Lipid and lipoprotein measurements in a normal adult American population

From a parent population of 774, a subpopulation of 160 normal adults ages 27-66 was randomly selected, 20 from each decade and sex. A detailed comparison was made by analytic ultracentrifugation and complete agarose gel electrophoresis on serum and the 1.006 g/ml top and bottom preparative ultracentrifuge lipoprotein fractions. The latter was internally standardized by total lipid and plasma total cholesterol and triglyceride determinations giving normal reference lipoprotein values. The reading procedure allowed the identification and quantification of floating beta and sinking pre-beta. In the subpopulation, there were two of the former and 13 of the latter. For large scale clinical application of such quantitative lipoprotein electrophoresis full automation of the microdensitometry and calculations will be required.     

Cholesterol and triglyceride distributions in an adult employee population: The Pacific Northwest Bell Telephone Company health survey

Plasma cholesterol and triglyceride are presented for 4503 adult employees of the Pacific Northwest Bell Telephone Company. Cross-sectional age and sex specific means and percentiles are shown. Females are classified by use or nonuse of exogenous sex hormones. Comparisons are examined among these groups, between blacks and whites, and among education and occupation categories. In these cross-sectional data, cholesterol and triglyceride generally increase with age and exhibit distinct differences by sex and by hormone use.     

Effects of riser height and total solids inventory on the gas-solids in an ultra-tall CFB riser

More and more CFB boilers with large capacity and ultra-tall furnaces are used for power generation. Understanding the fluid dynamics in the ultra-tall furnace is important. However, existing studies on fluid dynamics in the CFB furnace are limited to the risers with rather short height. An experimental study was conducted with a cold CFB test rig of 240 mm in I.D. and 38 m and 54 m in height respectively. The influences of total solid inventory I_v, and fluidizing gas velocity U_g on the axial voidage profile along the riser and solid circulation rate G_s were investigated. Experimental results showed that when U_g exceeded the transport velocity, an S-shaped voidage profile characterized by fast fluidization was established in the riser. In such circumstance, the voidage at top dilute section kept constant and G_s reached saturation carrying capacity (G_s = G_s^?) and inappreciably change with riser height and I_v. Moreover, G_s^? increased from 40 kg to 50 kg when the riser height increased from 38 m to 54 m. The results indicated that even for the 600 MWe supercritical CFB boiler with a 54 m tall furnace, only a modest increase of I_v and power of forced draft fans is needed to obtain high enough G_s to meet the requirements of heating surfaces arrangement in furnace and the circulation loop. The necessary conditions to form the S-shaped profile of voidage in the riser were also discussed.     

Slugging bed height of polyethylene particles in a fluidized bed with an expanded section

Slugging experiments were performed in a fluidized bed of 7 cm ID and 50 cm in height to examine the maximum bed height with an expanded section. High-density polyethylene (HDPE) particles of 0.5 mm were employed as the bed materials. The slugging bed height was linearly increased with the gas velocity in the beds of uniform cross section as well as expanded section with different slope. From the results of this study, it was found that the existing correlation to predict the slugging bed height based on the heavier particles for the uniform cross section area was satisfactorily applied for the lighter particles of HDPE and for the expanded section, a slight modification was made for the particle of HDPE in the slugging bed. Presented at the Int’/Sym. on Int’l Symp. on Chem. Eng. (Cheju, Feb. 8–10, 2001), dedicated to Prof. H. S. Chun on the occasion of his retirement from Korea University.     

PE-UHMW分子量及其分布表征技术进展

针对常规分子量表征手段很难用于超高分子量聚乙烯(PE–UHMW)的分子量测试现状,综述了PE–UHMW分子量分布及其大小测试方法。PE–UHMW分子量分布可以通过以下方式实现:利用不同温度时溶解性不同实现分离,利用凝胶色谱柱实现分离,利用运动速度与分子量之间的关系实现分离。PE–UHMW分子量测试目前主要有黏度法、凝胶色谱连用技术、流变仪法等,其中黏度法在实际生产中得到了广泛应用,但这种方法重复性差,其可靠性和准确性还不稳定。     

A new alternative for estimating recommendations of protein intake in humans. Protein requirements of an adult population fed with a diet based on rice and beans

This paper proposes a new approach to estimate the protein needs of a population; recommendations are also made on the protein intake of adults fed diets based on rice and beans. For this purpose, the nitrogen balance data previously reported for 40 adult human subjects who had participated in 160 nitrogen balance periods fed diets based on rice and beans, with and without animal protein and/or energy supplementation were used. The proposed method is based on the curvilinear response between nitrogen intake and its nitrogen balance. The second degree equation describing the relationship between nitrogen balance and intake is calculated. Using the mathematical concept of the first and second derivatives, the point of inflexion is obtained, and interpreted as that condition wherein the individual utilizes with maximum efficacy the ingested nitrogen; nitrogen ingestion, which corresponds to that point, is therefore taken as the dietary nitrogen recommendation for the individual. When the values obtained by means of the quadratic equation are compared to those obtained by the traditional linear equation, values were found to be statistically equal (p less than 0.05) for both calculation methods. The recommended protein intake of an adult population fed a diet based on rice and beans was 0.80 and 0.77 g/kg/day for the quadratic approach, and for the conventional method, respectively. When this diet was supplemented with 10% milk protein and with the same energy level, the calculated values were 0.64 and 0.71 g protein/kg/day for both methods, in this same order. The essential amino acid intake and absorption values were also calculated from the protein levels recommended by both methods to be in nitrogen balance, from a diet based on rice and beans. Findings revealed, in all cases, that the intakes of each and all essential amino acids met those levels indicated by FAO/WHO, with the exception of isoleucine and the sulphur-containing amino acids, which apparently limit the quality of the diet.     

Interfacial tension from the height and diameter of sessile drops and captive bubbles with an arbitrary contact angle

A method has been developed to calculate the interfacial tension of sessile drops and captive bubbles of arbitrary contact angle by measuring the drop diameter and vertical distance to the apex at arbitrary horizontal planes within the drop. The procedure works in theory for any contact angle with an accuracy on the order of 0.1%. However, practical limitations reduce the range of angles to roughly 50°–180° but do not restrict the range of interfacial tensions (at least 0.01 mJ/m² to 72.0 mJ/m²). The optimal strategy is to use the method at several points on a single drop and to calculate the mean and standard deviation of the resulting interfacial tensions.     

Prediction of steady-state dispersion height in the disengaging section of an extraction column from batch settling data

The decay of a dense dispersion formed under calm conditions is given by Experiments in a batch vessel with different liquid-liquid systems and initial drop diameters show that the dimensionless constant K is equal to 26,000. This agrees with the value previously determined from the variation in steady-state dispersion height with throughput in spray columns, the analogous equation being The results can thus be used to predict the height of the dispersion formed in the disengaging section of extraction columns.     

内源性危险信号低分子量硫酸乙酰肝素的免疫佐剂作用

目的 研究内源性危险信号低分子量硫酸乙酰肝素(Heparan sulfate,HS)的免疫佐剂作用。方法按照HS的免疫剂量、免疫途径和免疫程序将ICR小鼠分组,同时设HBsAg对照组和铝佐剂对照组,分别于末次免疫后4、8、12、16、20和24周,采用ELISA法检测小鼠血清中的特异性IgG抗体水平;选择体液免疫效果最佳的剂量组免疫BALB/c小鼠,同时设空白对照组、抗原对照组和铝佐剂对照组,于末次免疫后8周,采用乳酸脱氢酶(LDH)法检测细胞杀伤活性。结果空白对照组小鼠在各检测时间点均未见IgG抗体产生。除第4组外,各实验组抗体滴度均在末次免疫后第8周达峰值,随着时间的推移,抗体水平呈下降趋势。第43组抗体水平升高快,峰值高,持续时间长;在实验剂量范围内,随着HS剂量的增加,针对HBsAg的特异性抗体水平也增加;HS的最佳剂量为100μg;皮下注射HS的免疫增强作用最佳,优于肌肉和鼻腔免疫;免疫程序对HS的佐剂作用影响不大。HS能诱导小鼠产生特异性的CTL细胞免疫效应,细胞杀伤活性显著高于空白对照组、抗原对照组及铝佐剂对照组(P﹤0.001)。结论 HS具有免疫佐剂作用,既能有效增强特异性体液免疫应答,又能显著诱导CTL细胞免疫效应,是一种优于铝佐剂的潜在人用疫苗佐剂。     

Weight loss and body composition

Body fat accounts for much of the excess weight in obese persons; but the amount of lean body tissue (muscle and other protein tissue) in the obese individual is similar to that found in the normal individual. In weight loss primarily excess fat should be lost; not essential protein tissue. Complete fasting has been proposed as a technique for losing weight, in lieu of partial caloric restriction. The present studies were carried out to evaluate these techniques for weight loss. Changes in body composition of obese rats were determined after the animals lost one third of their body weight on different regimens. Obese animals which were restricted to 37.5 and 60% of ad libitum caloric intakes required 53 and 93 days, respectively, to lose this weight, whereas those which were totally fasted required only 24 days. There were significant differences in body composition of these groups after weight loss. Fasted animals lost more protein and less fat than did animals restricted in caloric intake; the fasted animals lost 18% of their total body protein, whereas the calorically restricted animals lost only 8–9%. Epididymal fat pads were twice as large in the fasted animals as in the calorically restricted animals. In fasted animals, liver weight loss was greater than in restricted animals, but liver fat levels were still high, as in the obese rats. Liver cholesterol levels were also elevated in fasted animals. Neither the amount of fat nor the type of fat (unsaturation) in the diet had any significant effect on the rate of weight loss or on gross body composition. Type of fat affected fatty acid composition of plasma, but not of liver or depot fat. The development of new methods for determining body composition in man has permitted reasonably accurate estimates of the amount of excess body fat in obese individuals. In obese subjects who lost weight on restricted caloric intakes of an otherwise nutritionally complete diet, most of the weight loss was as body fat, without significant loss of lean body tissue. The studies in man confirm the findings in animals. The extra weight in obesity is mainly fat, with very little protein and some water; when weight is lost by restricted intake of a good diet, the composition of the tissue burned is quite similar to that comprising the extra weight. Fasting gives more rapid weight loss, but apparently less favorable changes in body composition.     

Growth in height of indigenous and non indigenous Chilean children

The aim of this study was to compare growth curves of stature in indigenous and non-indigenous children belonging to two levels of poverty and to establish the onset and evolution of the deficit. Children of indigenous and non-indigenous background living in communities of extreme and low poverty in Chile were studied and their height-for-age Z-score from birth until 6 year of age were compared. Mean weight at birth was within normal range, and no differences were found in ethnicity and levels of poverty. Length at birth was below the reference with the exception of the non indigenous newborn from counties of low poverty. Deficit in growth showed an early start, furthermore in indigenous children belonging to the extreme poverty, is from birth and progress through the 18 months. At 72 months the deficit reached -1.1 z scores in the indigenous of the extreme poverty versus -0.7 in the non indigenous group. Children from the low poverty had a Z-score of -0.4 z scores at 72 months without differences between ethnias. Indigenous of the extreme poverty had less accumulative growth while the indigenous of the low poverty areas growth satisfactory without differences with the non indigenous.     

Pulse height defect in pCVD and scCVD diamond based detectors

Polycrystalline (pCVD) and single crystal (scCVD) diamond films grown from Chemical Vapour Deposition (CVD), if sufficiently pure at Raman analysis, are very good materials for beam or flux monitors inside accelerators or nuclear reactors. This is because they are very hard to damage in high radiation fields and very resistant to high temperatures. Films of pCVD diamond are, however, not so good as spectroscopy detectors due to inhomogeneities induced by their growth in grains with the consequent presence of grain boundaries which worsen their energy resolution. The latter can be significantly improved by growing scCVD diamond films onto HPHT synthetic diamond substrates. We have shown that it is possible to measure the density of defects inside diamond specimens using as probes suitable penetrating nuclear radiations. With the preliminary results reported here we'll show that, bombarding CVD diamond films grown at Roma “Tor Vergata” with energetic protons and ⁴He, ⁶Li and ¹²C ions produced in the accelerators of Catania laboratories, the pulse height defects are higher than those in silicon detectors and likewise well described by a power law in the deposited energy. Furthermore, we'll show that pulse heights for the same particles seem to depend on the duration of the measurement, thus exhibiting a sort of depolarization of the insulator when exposed to the electric voltage which makes it a particle detector.     

相对分子质量及其分布对等规聚丙烯性能的影响研究

通过加入DCP来改变等规聚丙烯相对分子质量的大小及分布,研究了等规聚丙烯相对分子质量及其分布对其性能的影响。结果表明:加入DCP后,iPP的相对分子质量降低、分布变窄,促使聚丙烯结晶速度进一步提高,晶体尺寸进一步减小,iPP中的β晶型消失。随iPP的相对分子质量降低、其分布变窄,iPP的力学性能略微下降。     

Dietary and other lifestyle correlates of serum folate concentrations in a healthy adult population in Crete, Greece: a cross-sectional study

Background  

Folate has emerged as a key nutrient for optimising health. Impaired folate status has been identified as a risk factor for cardiovascular disease, various types of cancers, and neurocognitive disorders. The study aimed at examining the distribution and determinants of serum folate concentrations in a healthy adult population in Crete, Greece.     

涂料用聚合树脂的分子量及分子量分布与性能的关系

概述K、α参数未知时的求证方法。并当K、α参数已知时,如何使用其参数用于分子量分布的测定步骤,以及采用待测物与参照物GPC流出曲线定性比较分子量分布的实用技术。讨论了聚合树脂的分子量和分子量分布与性能的关系。     

凝胶色谱法测定木素分子量及其分布

综述了凝胶色谱法测定本素分子量及其分布的方法和取得的进展。新型高效凝胶位的出现,使凝胶色谱法可以测定多种本素分子量。用凝胶色谱法测定木素的分子量,需要根据样品的性质选择色谱技、流动相和标样,并通过实验确定合适的色谱条件。本素样品可能需要经过适当的预处理以适应色谱柱和流动相的要求。     

Maternal height and growth of Chilean premature infants

The aim of this study was to analyze the association between maternal age and growth of infants born preterm through the first 4 mo. of age. We prospectively studied 80 infant born at the hospital Herminda Martin in Chilean between January and September 1995 with birthweight < 2500 g and gestational age < or = 36 weeks; those born small for date, with congenital malformations or developing chronic diseases were excluded. The modified Graffar was applied to study socioeconomic status and growth, morbidity and type of feeding was monthly registered at Primary Care Centers where they were controlled. The maternal height was categorized as small (< -1 SD, n = 14), normal (> -1 SD and < +1 SD, 147.6-161.8 cm, n = 52) or tall (> +1 SD, n = 14). Sons from tall mothers presented better W/A z score at 4 mo than those from normal or small mothers (0.85 +/- 0.8 vs 0.31 +/- 0.6, p < 0.03 and 0.85 +/- 0.8 vs 0.15 +/- 0.8, p < 0.04). Length gain through the 4 mo was also better of infants with tall mothers (15.3 +/- 1.4 vs 13.7 +/- 2.3 and 13.6 +/- 2.2 cm, ANOVA p < 0.04), reaching better z-scores (0.2 +/- 0.3 vs -0.7 +/- 0.6 and -0.9 +/- 0.9, ANOVA p < 0.0001). The maternal schooling > 8 y was also associated to infant growth: those with tall mothers presented better L/A z-score at 4 mo than those with normal or small mothers (0.27 +/- 0.3 vs -0.89 +/- 0.7 and -0.85 +/- 0.5 p < 0.001). Exclusive breast milk was present in 7% of tall, 25% of normal and 0% of small mothers. No differences in morbidity were observed between groups. We conclude that Chilean infants born preterm from mothers > 1.61 m present a better growth that those with smaller mothers since the first 4 months of age.