Challenges for room temperature operation of electrically pumped GeSn lasers.

Recent demonstrations of room-temperature lasing in optically pumped GeSn show promise for future CMOS compatible lasers for Si-photonics applications. However, challenges remain for electrically pumped devices. Investigation of the processes that limit device performance is therefore vital in aiding the production of future commercial devices. In this work, a combined experimental and modelling approach is utilised to explore the dominant loss processes in current devices. By manipulating the band structure of functioning devices using high hydrostatic pressure techniques at low temperature, the dominant carrier recombination pathways are identified. This reveals that 93 ± 5% of the threshold current is attributable to defect-related recombination at a temperature, T = 85 K. Furthermore, carrier occupation of L-valley states (carrier leakage) is responsible for 1.1 ± 0.3% of the threshold current, but this sharply increases to 50% with a decrease of just 30 meV in the L- Γ separation energy. This indicates that thermal broadening of a similar order may reproduce these adverse effects, limiting device performance at higher temperatures. Temperature dependent calculations show that carrier occupation of indirect valley L-states strongly affects the transparency carrier density and is therefore very sensitive to the Sn composition, leading to an effective operational temperature range for given Sn compositions and strain values. Recommendations for future device designs are proposed based on band structure and growth optimisations.

Acquired limb deficiencies. 2. Perioperative management.

UNLABELLED: This self-directed learning module highlights recent advances in the evaluation and management of complications arising from diabetes and peripheral vascular disease leading to amputation. It is part of the chapter on acquired limb deficiencies in the Self-Directed Physiatric Education Program for practitioners and trainees in physical medicine and rehabilitation. This article includes discussion of comorbid conditions that may have an impact on the prosthetic rehabilitation of a transtibial amputee. It also offers essential information regarding perioperative management of an upper extremity amputee. OVERALL ARTICLE OBJECTIVE: To review recent advances in the evaluation and management of complications arising from diabetes and peripheral vascular disease leading to amputation.

Acquired limb deficiencies. 4. Troubleshooting.

UNLABELLED: This self-directed learning module offers practical analyses of and solutions for common clinical problems of amputees. It is part of the chapter on acquired limb deficiencies in the Self-Directed Physiatric Education Program for practitioners and trainees in physical medicine and rehabilitation. The information presented here has been designed to be useful also to other interested professionals, including prosthetists, physical therapists, occupational therapists, and nurses. Topics covered include the management of typical obstacles encountered in upper limb amputees, and the diagnosis and treatment of phantom and residual limb pain. Diagnostic and treatment approaches to skin breakdown in the transtibial amputee and to knee instability in the transfemoral amputee are also presented. OVERALL ARTICLE OBJECTIVE: To analyze common clinical problems of amputees.

Profile of the Kaiser Permanente Health Plans.

Kaiser Permanente is a group practice model health maintenance organization (HMO), with all its established regions being federally qualified under the HMO Act of 1973. Kaiser Permanente is comprised of Kaiser Foundation Hospitals, which owns and operates hospitals, Kaiser Foundation Health Plan, Inc., which arranges member prepaid services, and the Permanente Medical Groups, partnerships or corporations of physicians who provide professional services. After originally being based in California and Oregon/Washington, Kaiser Permanente is expanding in various regions around the country.