Search

For three-dimensional bio-printed cell-laden hydrogel tissue constructs, the well-designed internal porous geometry is tailored to obtain the desired structural and cellular properties. However, significant differences often exist between the designed and as-printed scaffolds because of the inherent characteristics of hydrogels and cells. In this study, an iterative feedback bio-printing (IFBP) approach based on optical coherence tomography (OCT) for the fabrication of cell-laden hydrogel scaffolds with optimal geometrical fidelity and cellular controllability was proposed. A custom-made swept-source OCT (SS-OCT) system was applied to characterize the printed scaffolds quantitatively. Based on the obtained empirical linear formula from the first experimental feedback loop, we defined the most appropriate design constraints and optimized the printing process to improve the geometrical fidelity. The effectiveness of IFBP was verified from the second run using gelatin/alginate hydrogel scaffolds laden with C3A cells. The mismatch of the morphological parameters greatly decreased from 40% to within 7%, which significantly optimized the cell viability, proliferation, and morphology, as well as the representative expression of hepatocyte markers, including CYP3A4 and albumin, of the printed cell-laden hydrogel scaffolds. The demonstrated protocol paves the way for the mass fabrication of cell-laden hydrogel scaffolds, engineered tissues, and scaled-up applications of the 3D bio-printing technique.

Aims. We investigated whether self-monitoring of blood glucose could be used to assess dawn phenomenon in Chinese people with type 2 diabetes mellitus (T2DM).Methods. A total of 306 people with T2DM underwent continuous glucose monitoring and self-monitoring of blood glucose for 72 h. A linear model was used to fit the optimal linear formula of the magnitude of dawn phenomenon (ΔDawn) and self-monitoring of blood glucose values.Results. The prevalence of dawn phenomenon was similar within different oral antidiabetic drug groups (42.5%, 31.5%, and 40.9%,P=0.216). Multiple variable linear regression showed that prebreakfast, prelunch, and predinner glucose measurements were independently and significantly correlated with ΔDawn. The linear formula between ΔDawn and blood glucose was as follows:ΔDawn mg/dL=0.557×prebreakfast−0.065×prelunch−0.164×predinner−20.894 mg/dL(adjustedR2=0.302,P=0.000).Conclusions. Dawn phenomenon could be partly assessed by blood glucose self-monitoring in Chinese people with T2DM using the abovementioned formula. The incidence of dawn phenomenon was similar among patients in different oral antidiabetic drug groups.

The special wind compensation system recently adopted by Federation Internationale de Ski (FIS; International Ski Federation) to consider the effects of changing wind conditions has caused some controversy. Here, the effect of wind on jumping distance in ski jumping was studied by means of computer simulation and compared with the wind compensation factors used by FIS during the World Cup season 2009/2010. The results showed clearly that the effect of increasing head/tail wind on jumping distance is not linear: +17.4 m/ − 29.1 m, respectively, for a wind speed of 3 m/s. The linear formula used in the trial period of the wind compensation system was found to be appropriate only for a limited range of jumping distances as the gradient of the landing slope slows down the rate of distance change in long jumps.

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

The aim of the study was to evaluate the effect that coronary artery bypass grafting (CABG) and aneurysmectomy in the same session have on QT dispersion (QTd) in moderate or severe left ventricular dysfunction.Forty-four patients underwent QT interval analyses before and 1 month after aneurysmectomy and CABG. QT interval and QTd were corrected for heart rate using the square root formula of Bazett (QTCB), the cubic root formula of Fridericia (QTCF), and the linear formula of Sagie et al (QT CS ).The mean pre- and postsurgery QTd results were 65.29 +/- 29.25 and 51.76 +/- 18.49 milliseconds, respectively; the corresponding findings for QT CF were 68.06 +/- 31.26 and 55.16 +/- 24.56 milliseconds; and the corresponding findings for QT CS were 66.53 +/- 32.22 and 51.10 +/- 18.29 milliseconds. With these 3 methods, the postoperative findings were significantly lower than the preoperative findings ( P.05 for all). In contrast, the opposite was true with the QT CB method (preoperative 71.1 +/- 65.80 vs postoperative 76.43 +/- 7.96 milliseconds, P.05).The study showed that based on the methods of Fridericia (QT CF ) and Sagie et al (QT CS ), QT intervals are significantly decreased after CABG and aneurysmectomy.

To date, no information is available comparing the prognostic significance of the QT interval corrected by Bazett’s equation with that corrected by linear formulas in patients after myocardial infarction. Because several reports1,2 demonstrated that heart rate measured on a standard electrocardiogram is a strong predictor of adverse outcome in patients after myocardial infarction, it is very probable that linear adjustment of the QT interval decreases the prognostic power of corrected QT interval. The present study compares the value of linearly and nonlinearly corrected QT intervals for identifying high-risk patients, and tests the hypothesis that more accurate adjustment of the QT interval for heart rate paradoxically decreases the prognostic significance of the corrected QT interval in patients with remote myocardial infarc

EDITOR: WE AGREE WITH BRANDT AND ASSOCIATES 1 THAT GOLDmann applanation tonometry (GAT) yields systematic errors in measurement of intraocular pressure (IOP) attributable significantly to variations in central corneal thickness (CCT). We further agree that “true” IOP is far more complex than can be modeled by a simple linear arithmetic correction. However, there are a few issues related to the study that may be worth further discussion. We would like to point out that two plywoods placed together can bear four times as much weight as one. GAT is based on corneal deformation to external pressure. The relationship between the degree of corneal deformation to external pressure and the corneal thickness is not linear, but exponential. Exponential IOP correction formulas 2,3 are available, and they should give a better estimate of “true” IOP than a simple linear formula. Using the exponential IOP correction formula we developed, we calculated the “true” IOP from the data presented in Table 3 of

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

Since the publication of Paper 5 of this series the so-called "Linear Formula" has been used in the study of a large number of individuals. Practically all of the subjects of respiration experiments in the Sage calorimeter have been measured in this way, and in addition Means1of Boston has used it as a factor in determining his normal base line of metabolism and the extent of the pathological variations. Means has found that the range of normal variation from the average is smaller and that the apparent depression of metabolism in obesity is much less marked when the linear formula, instead of Meeh's formula, is used to determine surface area. The accuracy of the linear formula has been shown in Paper 9 of this series. In order to correct the slight error in the factor for the arms, and also in order to clear up a few points

Twenty years ago body weight was used as the point of reference from which parenteral fluid requirements were calculated. As interest in fluids and electrolytes increased it became apparent, however, that weight alone could not serve as the point of reference for these calculations since the same amount of fluid per pound could not be given to an older child as was given to an infant. Formulas were therefore constructed utilizing surface area as the standard of reference upon which maintenance fluid requirements could be based. 1 Recently the rationale of the entire "surface area concept" has been questioned by Wilson and his associates. 2 These authors have pointed out the inadequacy of the data upon which the surface area "nomograms" are based, and they have raised other technical objections. (Twelve patients studied in 1915 served as the basis for the DuBois Linear Formula from which the surface area nomograms

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