Effect of lateral crural cut overlay and medial crural cut and overlay in creating and maintaining tip projection and rotation: a randomised single-blind trial.

Lateral crural cut and overlay (LCC) or medial crural cut and overlay (MCC) are two of the many techniques applied to ensure an adequate nasal tip projection and rotation, but little evidence supports their long-term efficacy. Fifty-four rhinoplasty candidates were studied prospectively in this randomised clinical trial. The subjects were randomly divided into two groups according to the use of LCC or MCC. The outcome measures were gaining and maintaining tip projection and rotation in the long term. Standardised photographs taken before and at three and 12 months after surgery were used to compare nasolabial angle and projection between groups. Patients' satisfaction with the cosmetic results and nasal obstruction were evaluated using the Standardised Cosmesis and Health Nasal Outcomes Survey (SCHNOS). LCC and MCC were each used in 26 cases. Preoperatively, the nasolabial angle, tip projection, and other characteristics were not significantly different between the groups. There was no significant difference in tip rotation stability (p = 0.624) and projection (p = 0.329) between the groups postoperatively, but patients' satisfaction with the cosmetic results was significantly higher in the MCC group (p = 0.046). It seems that both LCC and MCC are effective techniques in rhinoplasty. Compared with LCC, the use of MCC in qualified hands may increase the patients' satisfaction with the cosmetic results.

Synthesis and characterization of a highly strained donor-acceptor nanohoop.

A highly-strained, nitrogen-doped cycloparaphenylene (CPP), aza[6]CPP, was synthesized and then converted to a donor-acceptor nanohoop, N-methylaza[6]CPP, via alkylation of the nitrogen center. The energy levels of the lowest unoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO) for both molecules were then probed by cyclic voltammetry (CV), which revealed that the donor-acceptor nanohoop had a significantly lower LUMO energy relative to [6]CPP and aza[6]CPP. Density functional theory (DFT) revealed that the donor-acceptor nanohoop underwent a redistribution of the frontier molecular orbital (FMO) density such that a significant portion of the LUMO density resided upon the electron-deficient nitrogen-containing ring. This localization of LUMO density caused a large lowering in the LUMO energy of nearly a full electron volt, while the HOMO energy was less affected due to a large centralization of the FMO on the electron-rich phenylene backbone. This ultimately resulted in a net lowering of the HOMO-LUMO energy gap which was observed both experimentally and computationally. In addition, N-methylaza[6]CPP has a significantly lower energy LUMO than N-methylaza[8]CPP, illustrating that the FMO levels of donor-acceptor nanohoops can be tuned by adjusting the hoop size.

A simulation study of the winter bed crisis.

The winter bed crisis is a cyclical phenomenon which appears in British hospitals every year, two or three weeks after Christmas. The crisis is usually attributed to factors such as the bad weather, influenza, older people, geriatricians, lack of cash or nurse shortages. However, a possible alternative explanation could be that beds within the hospital are blocked because of lack of social services for discharge of hospital patients during the Christmas period. Adopting this explanation of why the bed crisis occurs, the problem was considered as a queuing system and discrete event simulation was employed to evaluate the model numerically. The model shows that stopping discharges of rehabilitating patients for 21 days accompanied by a cessation of planned patients for 14 days precipitate a bed crisis when the planned admissions recommence. The extensive "what-if" capabilities of such models could be proved to be crucial to the designing and implementation of possible solutions to the problem.

Evaluating the costs of alternative options for dementia services.

In the next decade the number of demented people is likely to increase. This has a financial impact on the resources allocated for health and social care. Classical methodologies for dealing with dementia include the historic model that has been criticised for its poor co-ordination between general practitioners, psychiatrists, social workers and the treatment services, and the needs-based approach that, although it involves a co-ordinating needs manager, does not prevent leapfrogging of patients. In order to overcome these problems we propose an annual screening of patients to take place in the needs-based models and compare this with a more sophisticated model in which after being screened patients are investigated for potential drug treatment. We also consider mix intervals for under 75 and over 75. Decision analysis is used to assess the different screening options. Assuming a 20% reduction by treatment of the cost of care we find optimal the investigation/treatment of all patients after screening. Sensitivity analysis shows that even an 8.5% reduction would make the needs-based models non-optimal.

A simulation modelling approach to evaluating length of stay, occupancy, emptiness and bed blocking in a hospital geriatric department.

The flow of patients through geriatric hospitals has been previously described in terms of acute (short-stay), rehabilitation (medium-stay), and long-stay states where the bed occupancy at a census point is modelled by a mixed exponential model using BOMPS (Bed Occupancy Modelling and Planning System). In this a patient is initially admitted to acute care. The majority of the patients are discharged within a few days into their own homes or through death. The rest are converted into medium-stay patients where they could stay for a few months and thereafter either leave the system or move on to a long-stay compartment where they could stay until they die. The model forecasts the average length of stay as well as the average number of patients in each state. The average length of stay in the acute compartment is artificially high if some would-be long-term patients are kept waiting in the short-stay compartment until beds become available in long-stay (residential and nursing homes). In this paper we consider the problem as a queueing system to assess the effect of blockage on the flow of patients in geriatric departments. What-if analysis is used to allow a greater understanding of bed requirements and effective utilisation of resources.