Maxwell's demon in the Ranque-Hilsch vortex tube.

A theory was developed that explains energy separation in a vortex tube, known as one of the Maxwellian demons. It appears that there is a unique relation between the pressures in the exits of the vortex tube and its temperatures. Experimental results show that the computed and measured temperatures are in very good agreement.

Discharge planning in a community hospital--a multidisciplinary approach.

The population of Singapore is ageing rapidly. Acute hospitals in Singapore are also experiencing an acute bed shortage. However, many elderly admitted to acute hospitals require a longer period of convalescence before they are able to go home. Community hospitals are most suitable to provide such care for the elderly patient. Patients could be discharged to the community hospitals to continue rehabilitation and convalescence. In addition this would also free the beds in the acute hospitals. However, there is a risk that without adequate discharge planning, the community hospitals would in turn also reach full capacity and no longer be able to accept patients. A discharge planning programme has been set up in a community hospital to address the following needs: 1) caring for a rapidly ageing population with increasing degrees of disability; 2) the shortage of beds in the acute hospitals; (3) the provision of holistic care and care-giver education, and 4) to prevent long term institutionalisation of the elderly as much as possible.

Multimodal approach in the management of 1163 ureteric stone cases.

One thousand one hundred and sixty three patients (male-852, female-311) with ureteric calculi requiring intervention were treated between April 1988 to July 1992. Four hundred and eleven cases were treated by ESWL Monotherapy, 414 by stone manipulation plus ESWL, 301 by retrograde ureteroscopic lithotripsy, 36 by percutaneous antegrade ureteroscopic lithotripsy and 1 case by open ureterolithotomy. There were 25 failures of the initial procedures. Only three cases that failed primary procedures required open surgery. Other complications include minor ureteric mucosal perforation (3%), infection (3%), transient moderate to gross haematuria (20%), loin ache (26.4%), irritative urination (34.4%) and low grade fever (30.1%). Current modalities used in the treatment of ureteric calculi produce good results and there is generally no primary role for any open surgery.

Declining case fatality rates for acute myocardial infarction in South Asian and white patients in the past 15 years.

OBJECTIVES: To determine whether case fatality rates in South Asian (Bangladeshi, Indian and Pakistani) patients with acute myocardial infarction have shown similar declines to those reported for white patients during the past 15 years. DESIGN: Cross-sectional, observational study. SETTING: Coronary care unit in east London. PATIENTS: 2640 patients-29% South Asian-admitted with acute myocardial infarction between January 1988 and December 2002. MAIN OUTCOME MEASURES: Differences over time in rates of in-hospital death, ventricular fibrillation and left ventricular failure. RESULTS: The proportion of South Asians increased from 22% in 1988-92 to 37% in 1998-2002. Indices of infarct severity were similar in South Asian and white patients, with declining frequencies of ST elevation infarction (88.2% to 77.5%, p < 0.0001), Q wave development (78.1% to 56.9%, p < 0.0001) and mean (interquartile range) peak serum creatine kinase concentrations (1250 (567-2078) to 1007 (538-1758) IU/l, p < 0.0001) between 1988-92 and 1998-2002. Rates of in-hospital death (13.0% to 9.4%, p < 0.01), ventricular fibrillation (9.2% to 6.0%, p < 0.001) and left ventricular failure (33.2% to 26.5%, p < 0.0001) all declined; these changes did not interact significantly with ethnicity. Odds ratios for the effect of time on risk of death increased from 0.81 (95% CI 0.70 to 0.93) to 1.02 (95% CI 0.87 to 1.21) after adjustment for ethnicity and indices of infarct severity (ST elevation, peak creatine kinase, Q wave development and treatment with a thrombolytic). CONCLUSIONS: In the past 15 years, death from acute myocardial infarction among South Asians has declined at a rate similar to that seen in white patients. This is largely caused by reductions in indices of infarct severity.