Lubricity of gold nanocrystals on graphene measured using quartz crystal microbalance.

In order to test recently predicted ballistic nanofriction (ultra-low drag and enhanced lubricity) of gold nanocrystals on graphite at high surface speeds, we use the quartz microbalance technique to measure the impact of deposition of gold nanocrystals on graphene. We analyze our measurements of changes in frequency and dissipation induced by nanocrystals using a framework developed for friction of adatoms on various surfaces. We find the lubricity of gold nanocrystals on graphene to be even higher than that predicted for the ballistic nanofriction, confirming the enhanced lubricity predicted at high surface speeds. Our complementary molecular dynamics simulations indicate that such high lubricity is due to the interaction strength between gold nanocrystals and graphene being lower than previously assumed for gold nanocrystals and graphite.

Establishment of consistent gait after fitting of new components.

Since the time required for a person with an amputation to become familiarized with a prosthesis after a change of a component is not known, the gait of a single subject, a man with a through-knee amputation, was examined with two different knee mechanisms interchanged in the same prosthesis. Several parameters were analyzed to determine when the subject's gait had stabilized sufficiently to permit confident assessment of the appropriateness of the knee mechanisms. At least one week of functional walking was required before a clinical decision could be made about the suitability of the component. For the purposes of research, it was deemed preferable to try knee mechanisms for at least 3 weeks to be sure pertinent gait parameters stabilized.

Benchmark data for elderly, vascular trans-tibial amputees after rehabilitation.

Benchmark data for lower limb amputees is often limited to young subjects who have had their amputations as the result of trauma. The majority of trans-tibial amputees rehabilitated are, however, elderly vascular amputees who may have different gait characteristics than their younger counterparts. Without biomechanical analyses to provide such benchmark data for this group it is not possible to compare the effects of different rehabilitation programmes, gait training regimens, or prosthetic devices. Twenty elderly vascular trans-tibial amputees rehabilitated at The Queen Elizabeth Centre, Ballarat, Australia and at least six months post-amputation were measured in respect of kinetic and kinematic parameters, and relationships between gait speed, consistency, and function were demonstrated. Further, an unexplained vertical ground reaction force pattern was demonstrated in faster, more functional amputees.

"Lens lasso" repositioning of dislocated posterior chamber intraocular lenses.

BACKGROUND: Dislocation of posterior chamber intraocular lenses poses unique surgical problems for the vitreous surgeon. Although many methods have been devised to correct this problem, none are easily accomplished. A new technique that simplifies this task is described. METHODS: Six patients with complete posteriorly dislocated posterior chamber intraocular lenses underwent this procedure. Five lenses had prolene haptics and one was all polymethylmethacrylate. All except one traumatic case were spontaneous dislocations. A 9-0 prolene suture was transocularly placed through opposite sides of the ciliary sulcus; slip knots were tied on the internal ends and these knots then used to "lasso" the intraocular lens haptics. This achieved, the lens was easily pulled back up into the ciliary sulcus. RESULTS: All patients tolerated the procedure well without any complications. Lens centering was excellent and the externalized sutures showed no erosion through the conjunctiva. Visual acuity was 20/40 or better in all but the one patient with traumatic dislocation, who had a final visual acuity of 20/100. Average length of follow-up period was 17 months. CONCLUSIONS: This surgical technique offers distinct advantages to the surgeon by eliminating cumbersome manipulation of the dislocated intraocular lens, more accuracy in lens replacement, and secure suture attachment to the lens haptics.

Diabetes in an elderly population. A controlled study of morbidity and outcomes.

OBJECTIVE: To determine in an elderly diabetic population the frequency of vascular and related disorders, the mortality, and outcomes compared with a matched control group. SETTING: The Queen Elizabeth Geriatric Centre, Ballarat, Victoria. METHOD: The medical records of all diabetics admitted between 1982 and 1987 inclusive, and a control group matched for age, sex and ward of admission were studied retrospectively. The presence of associated conditions and outcome parameters were entered in to a database and analysed statistically. RESULTS: Increased prevalence in individuals with diabetes of ischaemic heart disease (2.0:1.0), cerebrovascualr accident (1.9:1.0) and hypertension (1.5:1.0). Similar death rate, cumulative bed days, discharge destination and use of discharge services. CONCLUSION: Despite the more frequent presence of clinical vascular disease, an elderly population with diabetes had the same outcomes as matched controls and did not require more bed occupancy or use of community based services.

Rehabilitation outcomes for elderly lower limb amputees.

The outcome following rehabilitation for 92 vascular amputees admitted to the Queen Elizabeth Geriatric Centre, Ballarat between 1 January 1982 and 31 December 1987 is presented. Data includes age, sex, concomitant disease, mortality, length of hospital stay and acceptance of prosthesis. Statistical analysis reveals no predictive factors for mobility levels attained by amputees other than amputation type, no predictive factors for acceptance of prostheses, and no predictive factors for total length of hospital stay. As a consequence, the Queen Elizabeth Geriatric Centre will continue the practice of admitting all amputees who wish to use artificial limbs to the prosthetic programme, regardless of age or concomitant disease.

Comparison of the B-D urine culture kit with a standard culture method and with the MS-2.

A total of 100 random clinical urine specimens were divided and used to compare Becton, Dickinson & Co. B-D Urine Culture Kit-treated urine (BDU) with refrigerated urine (RU). Each RU-BDU pair was cultured with the standard calibrated loop-plate method and also screened with the Abbott Laboratories MS-2 system at 0, 5, and 24 h. An additional 158 positive urine specimens containing greater than 10(5) CFU/ml were tested by standard culturing and MS-2 at 0 and 24 h. In addition, growth curves were run for Escherichia coli containing RU-BDU pairs at 0 and 24 h, and MS-2 detection time frequencies were analyzed. Culture results showed few changes in colony counts at 0 and 5 h for RU and BDU specimens. At 24 h, there were decreased colony counts for 7.0% of RU and 17.7% of BDU specimens. MS-2 results showed detection rates at 0 h of 100% for RU and 82.9% for BDU specimens and at 24 h of 91.1% for RU and 63.3% for BDU specimens. The organisms most frequently missed at 24 h were E. coli, Pseudomonas aeruginosa, and Staphylococcus epidermidis. Growth curve analysis showed a 1-h delay of logarithmic growth in BDU specimens. MS-2 detection time analysis showed delayed positive reports owing to be extended detection time for BDU specimens. The B-D Urine Culture Kit is a convenient transport system; however, some difficulty in recovering organisms at 24 h with the standard culture method and increased difficulty with the MS-2 system were recognized.

Intraocular pressure decrease in normal volunteers following timolol ophthalmic solution.

Timolol ophthalmic solutions 0.5 per cent, 1.0 per cent, and 1.5 per cent lowered intraocular pressures significantly in normal human volunteers. Maximum lowering of the intraocular pressures was reached at two hours with the 0.5 per cent solution of timolol and at one hour with the 1.0 per cent and 1.5 per cent timolol ophthalmic solutions. The effect lasted the full seven hours of observations. No objective or subjective evidence of ocular irritation could be attributed to the drug. A single dose of timolol applied topically to the eyes of normal human volunteers had no effect on pupillary size, visual acuity, blood pressure, or pulse rate.