Blood, sweat, and tears: extraterrestrial regolith biocomposites with in vivo binders.

The proverbial phrase 'you can't get blood from a stone' is used to describe a task that is practically impossible regardless of how much force or effort is exerted. This phrase is well-suited to humanity's first crewed mission to Mars, which will likely be the most difficult and technologically challenging human endeavor ever undertaken. The high cost and significant time delay associated with delivering payloads to the Martian surface means that exploitation of resources in situ - including inorganic rock and dust (regolith), water deposits, and atmospheric gases - will be an important part of any crewed mission to the Red Planet. Yet there is one significant, but chronically overlooked, source of natural resources that will - by definition - also be available on any crewed mission to Mars: the crew themselves. In this work, we explore the use of human serum albumin (HSA) - a common protein obtained from blood plasma - as a binder for simulated Lunar and Martian regolith to produce so-called 'extraterrestrial regolith biocomposites (ERBs).' In essence, HSA produced by astronauts in vivo could be extracted on a semi-continuous basis and combined with Lunar or Martian regolith to 'get stone from blood', to rephrase the proverb. Employing a simple fabrication strategy, HSA-based ERBs were produced and displayed compressive strengths as high as 25.0 MPa. For comparison, standard concrete typically has a compressive strength ranging between 20 and 32 MPa. The incorporation of urea - which could be extracted from the urine, sweat, or tears of astronauts - could further increase the compressive strength by over 300% in some instances, with the best-performing formulation having an average compressive strength of 39.7 MPa. Furthermore, we demonstrate that HSA-ERBs have the potential to be 3D-printed, opening up an interesting potential avenue for extraterrestrial construction using human-derived feedstocks. The mechanism of adhesion was investigated and attributed to the dehydration-induced reorganization of the protein secondary structure into a densely hydrogen-bonded, supramolecular ß-sheet network - analogous to the cohesion mechanism of spider silk. For comparison, synthetic spider silk and bovine serum albumin (BSA) were also investigated as regolith binders - which could also feasibly be produced on a Martian colony with future advancements in biomanufacturing technology.

System validation and work practice efficiency gains of a new localization method for stereotactic radiotherapy.

The increased procedural demands of stereotactic localization techniques when compared with conventional treatment practices reduces machine efficiency, an outcome likely to be greatly magnified by the introduction of fractionation to stereotactic techniques. Currently in Australia and New Zealand there are no guidelines for the definition of efficiency. We sought to devise a system to simultaneously validate the accuracy and efficiency of the technique. The frameless relocation methods employed in the Medtronic Sofamor Danek (MSD) stereotactic radiotherapy (SRT) system were studied in the clinical setting. Accuracy has been determined according to the accumulation of errors throughout the planning and treatment process. The clinical demands of the system (staffing and resources) were analysed relative to conventional treatment approaches. Timing studies indicate a mean time of 19.7 min for treatment of a daily SRT fraction (4-5 arcs, single isocentre). Cost and staffing requirements are similar to those for conventional radiotherapy. It is concluded that with the system used, SRT is efficient for routine clinical implementation, with the level of efficiency increasing with increasing patient numbers. It is recommended that a common acceptance standard be developed to allow cross-institutional comparison of the clinical efficiency of new treatment techniques.

Introduction and implementation of the basic treatment equivalent in a Varian-based department.

The increasing popularity of 3-D planning leads to procedural alterations as both workload and resource utilization increase. Although the complexity of the techniques has increased (as well as the set-up and treatment times), the workload statistics must still include the number of fields treated. It is commonly known that machine statistics of fields treated per day do not accurately represent workload because there are major differences between techniques. A mantle treatment technique and an opposed spine technique both have (statistically) two fields, although the set-up requirements and treatment times are very different. A basic treatment equivalent (BTE) formula was reported in early 1999 by Delaney et al. and incorporates a large number of variables inherent in patient treatment. The formula considers different factors that affect overall treatment time, and aims to represent a more accurate treatment time indicator. The aim of introducing the BTE into the Department of Radiation Oncology at Sir Charles Gairdner Hospital was to create a more accurate scheduling system and even out workloads on all treatment units. Therefore the BTE formula was used to assess accuracy of treatment times in order to determine if the values could be relied upon as accurate time indicators. Patients undergoing a variety of treatment techniques were timed for the duration of their treatment procedure, and their treatment times compared to the time estimated using the BTE formula. A few minor alterations were made to the equation for treatment units with multi-leaf collimation (MLC). A trial conducted at Sir Charles Gairdner Hospital found that, using the BTE formula (with a few modifications required for the MLC treatment units), of 60 patients timed for the duration of their set-up and treatment, 85% of values were in the range of +/- 3 min, and 95% were in the range of +/- 5 min of the estimated times. Through the routine use of the BTE equation a more sensitive indication of treatment machine workload can be found. Advantages such as: (i) a more accurate measure of treatment workload (for comparison with other departments) and (ii) increased scheduling accuracy will succeed over the currently accepted system of fields per hour.

Age and secular trends in risk factors for cardiovascular disease in Busselton.

Mortality rates from heart disease and stroke in Australia have been falling for more than 20 years. No completely satisfactory explanations for this trend exist. However, it is believed to be due, at least in part, to changes in the incidence of cardiovascular disease arising from changes in the prevalence and severity of risk factors for cardiovascular disease. The adult community of Busselton in Western Australia participated in cross-sectional health surveys every three years from 1966 to 1981. This paper describes secular trends from 1966 to 1981 and age trends from 25 to 80 years for cardiovascular risk factors in Busselton men and women. Downwards secular trends were observed for mean blood pressure and smoking for men and women, upwards trends were observed for body mass index in men, and mean cholesterol was approximately constant over this period. The age and secular trends were consistent with other Australian studies conducted in the 1980s and with overseas studies. An estimated 67 per cent of the decline in cardiovascular mortality rates among Busselton men and 22 per cent of the decline among Busselton women may be attributed to changes in the prevalence of risk factors for cardiovascular disease.

1989-90 National Health Survey: prevalence of self-reported diabetes in Australia.

OBJECTIVE: To estimate the prevalence of self-reported diabetes in a representative population sample in Australia; to identify major differences in prevalence by State and Territory and by geographic origin; and to compare trends in prevalence over time. DESIGN: and setting: Analysis of data collected by the Australian Bureau of Statistics in the 1989-90 National Health Survey. The sampling frame (22,202 households and 54,241 people) ensured adequate representation from each State and Territory in Australia. RESULTS: Prevalences of self-reported diabetes/high blood sugar levels were 1.9% for males and 2.0% for females over all ages; 3.1% for men and 2.9% for women aged over 25 years; and 8.1% for men and 6.9% for women aged over 65 years. Interstate differences of borderline significance were found and will require validation in larger samples. Age-standardised prevalences were higher in subjects born in Southern Europe and lower in those born in Western Europe compared with Australian-born subjects. Prevalences were high in households where the language spoken was other than English. The frequency of self-reported diabetes appears to be rising. CONCLUSIONS: Australia has comparatively low total prevalences of self-reported diabetes/high blood sugar levels. High prevalences subsections exist, including the elderly and certain migrant groups

Serum insulin is a risk marker for coronary heart disease mortality in men but not in women.

Serum insulin 1 h post-glucose load is examined in this prospective study of 2971 Caucasoid subjects aged > 20 years in 1966 and followed to 1989. The serum insulin levels as a continuous variable show no significant linear association with coronary heart disease (CHD) deaths in either sex after accounting for age by Cox proportional hazards analysis. In males the quintile classes of serum insulin show a striking U-shaped pattern with both the highest and lowest quintiles having significant associations with CHD deaths. In females the insulin quintiles show no direct association. Analysis for interactions of risk variables indicate that in females the relative protection of low cholesterol levels is abolished by hyperinsulinaemia after 12 years. Thus, serum insulin is not a direct aetiological risk factor for CHD. The findings suggest that the associations are likely to be due to confounding effects of unmeasured variables including lipid subfractions.

An analysis of excess mortality rates for persons with non-insulin-dependent diabetes mellitus in Western Australia using the Cox proportional hazards regression model.

A cohort of 888 rural, nonaboriginal persons with non-insulin-dependent diabetes mellitus identified in Western Australia through surveys in 1978-1982 were followed for death until the end of 1986. A total of 257 deaths were observed. Excess mortality in this cohort as compared with the general Australian population was investigated by calculating standardized mortality ratios and using the Cox proportional hazards regression model with hazard rates for the general population as the baseline. The overall standardized mortality ratio was 1.83 (95% confidence interval 1.51-2.16) for women and 1.43 (95% confidence interval 1.18-1.67) for men. Cause-specific comparisons with the general population showed that the majority of excess deaths could be attributed to diseases of the circulatory system. Factors assessed at the baseline survey that were independently prognostic of shorter survival were early onset of diabetes (for females only), high plasma glucose level, retinopathy, macrovascular disease, albuminuria (for females only), and elevated plasma creatinine level. Reductions in life expectancy at 60 years of age as compared with the general population averaged about 5 years but could be as much as 16 years for female diabetics with early onset of diabetes, high plasma glucose levels, and several complications.

Deaths from diabetes are under-reported in national mortality statistics.

Subjects with diabetes who attended rural surveys in Western Australia from 1978 to 1982 were followed up to ascertain death rates and the causes of death recorded on death certificates. Cardiovascular disease was assigned as the direct cause of death in 63% of deaths, with equal rates in male and female subjects, and renal disease in 8% of deaths with the proportion in women (12%) being greater than that in men (4%). The diagnosis of diabetes was stated on only 65% of the death certificates, and in only 24% was diabetes recorded as a direct or antecedent cause. In the same cohort the Australian Bureau of Statistics coded diabetes as the underlying cause of death in 24%, while attributing deaths to cardiovascular disease in 50% of the cases. This study suggests that diabetes is considerably underreported both on doctors' death certificates and in the mortality figures of the Australian Bureau of Statistics.

An estimate of diabetes prevalence from a national population sample: a male excess.

We report the prevalence of diabetes in a population sample of 10,083 persons who were aged 25 to 64 years in eight city centres. One hundred and sixty-nine persons were known to have diabetes and 48 persons were newly-discovered to have diabetes on the basis of fasting hyperglycaemia (plasma glucose level, equal to or greater than 7.8 mmol/L). Type-1 diabetes was identified by clinical criteria and accounted for 19% of cases of known diabetes, but this proportion ranged from 67% of persons with known diabetes in the age-group of 25-29 years, to between 9% and 15% in the age-groups of persons who were 50 years of age and over. For both known and newly-discovered cases, persons with type-2 diabetes showed a significant male preponderance, which suggests that an environmental factor is operating preferentially on male subjects to cause this form of diabetes. The results of the present study, when taken with those of other recent prevalence studies, enable an approximate estimate of numbers of persons with diabetes in Australia. Approximately 250,000 persons have diagnosed diabetes, of whom 40,000 persons have type-1 diabetes, including 7000 persons who are less than 25 years of age. The number of persons with undiagnosed diabetes who could be identified on the basis of fasting hyperglycaemia is estimated to be 75,000; an additional 150,000 persons would be diagnosed to have diabetes if they were to undergo glucose tolerance tests. This study gave prevalence rates for known diabetes in Australia in 1984 of 1.6% at all ages and 2.4% for adults who were 21 years of age and older; additionally, the estimated prevalence rates for undiagnosed diabetes were 1.4% for all ages and 2.2% for adults.

Diabetes in Western Australian children: descriptive epidemiology.

The prevalence and incidence of diabetes mellitus in the age group zero to 14 years in Western Australia were determined from a survey by means of Schools Health Services. Additional information from the State's computer-linked hospital records system, the State's only children's hospital, diabetic clinics and physicians enabled virtually complete ascertainment of cases of childhood diabetes. Only 60% of school-age diabetic children were known to school nurses before the survey, but the nurses were able to identify two-thirds of the remainder during the survey. Among non-Aboriginal children, the prevalence of diabetes in the age group zero to 14 years was 0.59 per 1000 children and the incidence was 12.3 per 100,000 children per year. These rates are somewhat lower than those that have been reported from the United Kingdom and North America, and substantially lower than the rates that were reported from Scandinavia. All but one of the diabetic children who were identified required insulin and were assumed to be insulin-dependent. An excess of boys was found. None of 8715 Aboriginal or part-Aboriginal children had insulin-dependent diabetes mellitus, which indicates that this racial group has a low prevalence of this condition. In case--control studies, which used questionnaires for parents, no significant trends were found in relation to the history of immunizations or of specific viral illnesses except for a past history of varicella which was less frequent in diabetic children. A past history of established breast-feeding (of more than one week) was less frequent in diabetic children, as was the ingestion of vitamin C supplements before the onset of diabetes. Some evidence for a seasonality of onset was obtained. The diabetic children were absent from school for more days and had more admissions to hospital than did non-diabetic children. The majority of diabetic children were prescribed insulin twice a day or more often (84%); performed home blood-glucose monitoring (74%); and attended hospital diabetic clinics (91%).