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Although the fly ash concrete with machine-made sand (MSFAC) was widely used in recent years in China, it was lack of studies on relations of compressive strength at different ages. According to the specification of Chinese standard, there are three ways of admixing fly ash (FA) into concrete, i.e. the additional admixing, the equal-mass replacing cement and the over-mass replacing cement. In this paper, 56 groups test data with additional admixing FA, 98 groups test data with equal-mass replacing cement and 86 groups test data with over-mass replacing cement for MSFAC are summarized from published references. Three linear formulas and Slatter formulas are fitted and compared for MSFAC by the different methods of admixing FA, all of them have good fitness with test data. The compressive strength at 28d can be predicted by the compressive strength at 7d with linear formula and Slatter formula for MSFAC.

Objective To develop an age-based weight estimation rule in a Chinese population and to compare its performance with existing formulae. Design Population-based observational study. Setting Schools and kindergartens in Hong Kong. Subjects Healthy Chinese children aged 1–10 years old on their last birthday. Interventions Weight was measured to the nearest 0.2 kg. Main outcome measures Linear regression was used to derive a simple formula relating weight to the child's age on his or her last birthday. The accuracy and precision of different age-based weight formulae was compared using coefficient of variation, Bland Altman plots, and by determining the proportion of children with estimates >30% outside the actual weight. Results The Chinese Age Weight Rule is a simple linear formula that is more accurate than and at least as precise as any other age-based weight estimation rule: weight in kg=(3×age last birthday)+5. It is accurate and precise in children

Aim Currently, the widely adopted renal dynamic imaging in clinical practice uses Gates' method to calculate the glomerular filtration rate (GFR), but many researchers have proven that Gates' method may result in bias. Thus, this article explores alternative improved formulae to calculate GFR by renal dynamic imaging. Methods Three hundred and sixty-seven patients were selected and their GFR values were measured using renal dynamic imaging and the two-plasma method with 99mTc-diethylenetriaminepentaacetic acid (99mTc-DTPA) as the imaging agent. With the two-plasma GFR as reference value, two equations were obtained from linear and non-linear regression analyses between the renal uptake percentage and two-plasma GFR. The 367 patients were divided into two random groups, with the first group used to derive the regression formulae and the second to verify the formulae. Finally, all patients were studied to derive the formulae to calculate GFR. The comparison of our formulae with the commonly used Gates' formula was conducted by the Bland-Altman method. Results The linear and non-linear GFR formulae were as follows: GFR (ml/min/1.73 m2)=(631.633 x renal uptake percentage - 2.040) x 1.73/BSA (BSA, body surface area) and GFR (ml/min/1.73 m2)=(-1996.585 x renal uptake percentage2 + 1013.526 x renal uptake percentage - 12.739) x 1.73/BSA, respectively. The biases of the GFR values calculated using the linear and non-linear formulae and Gates' formula relative to the two-plasma GFR were -2.5 +/- 19.1 ml/min/1.73 m2, -2.0 +/- 19.3 ml/min/1.73 m2 and 3.4 +/- 19.4 ml/min/1.73 m2, respectively. Conclusions The GFR values calculated using our new formulae correlate better with the reference GFR value than does GFR calculated by Gates' formula, and the GFR values measured using the non-linear formula are more accurate than those obtained using the linear formula.

Dialyzer clearance K is usually presented as K = K0 + Tr Qu, were Qu is ultrafiltration rate, K0 is clearance for Qu = 0, and Tr is transmittance coefficient. Although a simple and accurate mathematical description of K0 is widely used, only a somewhat inaccurate formula for Tr that predicts a linear relationship between Tr and K0 has been proposed before. In this study the detailed investigation of Tr using a one-dimensional theory of a dialyzer is presented. In general, the application of a one-dimensional theory requires sophisticated numerical methods, but for small and middle molecular weight solutes an analytical formula for K can be derived. Tr predicted by the developed theory in comparison to Tr predicted by the previous linear formula is higher for small molecular weight solutes and lower for middle and large molecular weight solutes. These theoretical results were confirmed in experiments carried out in vitro for hollow-fiber dialyzers and small molecular weight solutes (urea, creatinine, sodium, TcO4) as well as middle molecular weight solutes (vitamin B12).

The use of a Neubauer chamber is a broadly employed method when cell suspensions need to be quantified. However, this technique may take a long time and needs trained personnel. Spectrophotometry has proved to be a rapid, simple and accurate method to estimate the concentration of spore suspensions of isolates of the genus Fusarium . In this work we present a linear formula to relate absorbance measurements at 530 nm with the number of microconidia/ml in a suspension.

The need for normal figures on the growth of different parts of the body presented itself to me as a result of my studies on the growth and metabolism in pathologic cases during the last two years. 1 Since these data were not available, figures were compiled from a series of body surface measurements, taken, according to the Du Bois linear formula, on a group of clinically normal American children on whom studies had previously been made to determine the normal standards of basal metabolism. 2 These were average children within the accepted normal limits of height and weight for age, and do not represent exceptionally well nourished or poorly developed children. A description of these children has been given in an earlier publication. 2 The measurements were plotted on charts, and smoothed curves drawn to indicate the trend of growth of the different parts of the body. These curves

This series of untreated mongolian idiots, between the ages of 4 months and 10 years, has been studied from the point of view of growth of different parts of the body. The findings have been plotted to the growth curve of normal children, constructed from a series of body surface measurements taken according to the DuBois linear formula. In Chart 1 the standing heights of these cases are shown according to age. These findings show a close proximity up to the first year of life, after which there is a tendency for the mongolian idiot to be shorter than the normal. While this may be said to be due in some cases to the occurrence of rickets, which is frequently seen in this condition, it is by no means the sole explanation, and the retardation of growth is not so pronounced as it is in cretinism. On the basis of