Effect of dextroamphetamine and methylphenidate on calcium and magnesium concentration in hyperactive boys

Levels of calcium in plasma, red blood cells, and mononuclear blood cells, levels of calcium in plasma, and the plasma calcium-to-magnesium ratio were measured at baseline and after 3 weeks of each drug phase of a double-blind, placebo-controlled study of methylphenidate and dextroamphetamine in hyperactive boys. Levels of magnesium in plasma were significantly higher after 3 weeks of dextroamphetamine treatment, and the calcium-to-magnesium ratio was significantly lower after 3 weeks of either drug compared with the baseline or placebo condition. There was no change in magnesium levels in red blood cells or mononuclear blood cells. These measures were obtained 30 minutes before the morning dose and at 9 a.m., 9:30 a.m., 10:30 a.m., 11:00 a.m., and noon on the last day of each 3-week phase. Analysis of variance revealed a drug effect on plasma magnesium and on the calcium-to-magnesium ratio but no drug x time interaction. Although these changes were not correlated with the time course of acute symptomatic response to stimulant therapy, the decrease in the ratio may be relevant to side effects and treatment resistance associated with stimulant use.     

Quantification of acute phase reactants after muscle biopsy

Blood concentrations of six acute phase reactants (ESR, neutrophil count, fibrinogen, haptoglobin, alpha 1-antitrypsin, and ferritin), parameters of muscle necrosis (myoglobin, CK, ALT, and AST) as well as hemopexin, iron, and TIBC were determined before and for 7 consecutive days after muscle biopsy in patients and in a control group. A muscle biopsy was chosen as a standardized surgical procedure that induces a mild transient inflammatory response. After muscle biopsy, a significant increase occurred in five (ESR, neutrophil count, fibrinogen, haptoglobin, and alpha 1-antitrypsin) of the six acute phase reactants. The concentration of serum ferritin did not show a significant change. A significant decrease was noted in the serum iron concentration and a significant increase occurred with CK and myoglobin secondary to the muscle biopsy. Thus the inflammation of a muscle biopsy produces a significant acute phase reaction.     

Misuse of automated decision aids: Complacency, automation bias and the impact of training experience

The present study investigates automation misuse based on complacency and automation bias in interacting with a decision aid in a process control system. The effect of a preventive training intervention which includes exposing participants to rare automation failures is examined. Complacency is reflected in an inappropriate checking and monitoring of automated functions. In interaction with automated decision aids complacency might result in commission errors, i.e., following automatically generated recommendations even though they are false. Yet, empirical evidence proving this kind of relationship is still lacking. A laboratory experiment (N=24) was conducted using a process control simulation. An automated decision aid provided advice for fault diagnosis and management. Complacency was directly measured by the participants’ information sampling behavior, i.e., the amount of information sampled in order to verify the automated recommendations. Possible commission errors were assessed when the aid provided false recommendations. The results provide clear evidence for complacency, reflected in an insufficient verification of the automation, while commission errors were associated with high levels of complacency. Hence, commission errors seem to be a possible, albeit not an inevitable consequence of complacency. Furthermore, exposing operators to automation failures during training significantly decreased complacency and thus represents a suitable means to reduce this risk, even though it might not avoid it completely. Potential applications of this research include the design of training protocols in order to prevent automation misuse in interaction with automated decision aids.     

An experimental approach for smelting tin ores from Northwestern Iberia

ABSTRACT

In the present work microstructural and chemical analysis of tin and slag that resulted from three smelting experiments reconstructing prehistoric conditions are presented. Cassiterite ores were collected from northwestern (NW) Iberian deposits and were smelted in a small open pit. Results show that the loss in tin can be very high, up to 80%, mainly as a result of volatilization of Sn species. The experiments show that using handmade leather bag bellows and clay tuyeres, temperatures can easily reach >1200°C. The tin produced was a very pure (Sn) solid solution, with the presence of dispersed inclusions or phases of various composition. These included FeSn and FeSn₂ intermetallics and small metallic W inclusions. Slags could be grouped into three types based on their physical characteristics, and bulk chemical analysis could relate each type as being a product from the reaction of ore material or a product from the reaction with the crucible material. Generally, it was found that in spite of very low recovery rates, the tin produced by this simple technique would have been adequate for a domestic small-scale production.     

Sensing characteristics of NIR localized surface plasmon resonances in gold nanorings for application as ultrasensitive biosensors

The optical responses of 75-150 nm diameter gold nanorings to changes in local refractive index have been quantified by near-infrared extinction spectroscopy and compared to DDA calculations and an analytical approach. The "bulk" refractive index sensitivities of gold nanorings are substantially (>5 times) larger than those of nanodisks with similar diameters. Nanorings retain a significantly larger sensitivity than nanodisks at the same spectral position, demonstrating a clear shape dependence that may correlate to a systematic difference in the influence of the dielectric substrate. The nanoring bulk refractive index sensitivity scales linearly with plasmon peak position. The spectral sensitivity to thin films of alkanethiols gave a shift of approximately 5.2 nm/CH2 unit while bulk sensitivities as high as 880 nm/RIU were observed, the highest such reported sensitivities. Both bulk and thin dielectric film sensitivities correlated well with theory. Real-time label-free monitoring of protein binding via molecular recognition was demonstrated.     

Overlaying communities and topics: an analysis on publication networks

Two layers of enriched information are constructed for communities: a paper-to-paper network based on shared author relations and a paper-to-paper network based on shared word relations. k-means and VOSviewer, a modularity-based clustering technique, are used to identify publication clusters in the two networks. Results show that a few research topics such as webometrics, bibliometric laws, and language processing, form their own research community; while other research topics contain different research communities, which may be caused by physical distance.     

A Capillary Tube Viscometer Designed for Measurements of Hydrogen Gas Viscosity at High Pressure and High Temperature

A capillary tube viscometer was developed to measure the dynamic viscosity of gases for high pressure and high temperature. The apparatus is simple and designed for safe-handling operation. The gas was supplied to the capillary tube from a high-pressure reservoir tank through a pressure regulator unit to maintain a steady state flow. The measurements of a pressure drop across the capillary tube with high accuracy under extreme conditions are the main challenge for this method. A differential pressure sensor for high pressures up to 100 MPa is not available commercially. Therefore, a pair of accurate absolute pressure transducers was used as a differential pressure sensor. Then the pressure drop was calculated by subtracting the outlet pressure from the inlet one with a resolution of 100 Pa at 100 MPa. The accuracy of the present measurement system is confirmed by measuring the viscosity of nitrogen as a reference gas. The apparatus provided viscosities of nitrogen from ambient temperature to 500 K and hydrogen from ambient temperature to 400 K and for pressures up to 100 MPa with a maximum deviation of 2.2 % compared with a correlation developed by the present authors and with REFPROP (NIST).     

广西4种丛生竹材解剖特征的对比研究

采用生物解剖学方法,对广西4种丛生竹(撑篙竹、粉单竹、吊丝竹、青皮竹)的主要解剖特征进行了系统研究,以期为优质制浆造纸竹材的合理筛选提供基础数据。研究结果表明,4种丛生竹的维管束形态均属于断腰型,平均纤维组织比量、纤维长度、长宽比和壁腔比分别介于40.2%~46.8%、1.75~3.54mm、117~229、2.50~5.90之间。在竹壁径向上,维管束密度由竹黄向竹青逐渐增大,而双壁厚呈减小的趋势,竹壁径中部的纤维长度、宽度和腔径均为最大。综合来看,4种丛生竹适宜作为制浆造纸原料。其中,撑篙竹的纤维性能与毛竹相近,粉单竹、青皮竹和吊丝竹的纤维性能更优。     

Factors Explaining Interpersonal Variation in Plasma Enterolactone Concentrations in Humans

Lignans are diphenolic plant compounds with potential health modulating properties that are absorbed to the circulation and metabolized to the enterolignans enterodiol (END) and enterolactone (ENL) by gut microbiota. Epidemiological studies have inconsistently shown that a high lignan intake and circulating ENL are associated with reduced risk of breast‐, prostate‐, and colorectal cancer as well as cardiovascular disease and total and cause‐specific mortality. Inconsistencies can be due to interpersonal variation of ENL formation or responses. The aim of this review is to identify and evaluate the impact of factors influencing variability in plasma concentrations of the main enterolignan, ENL. The main determinants of plasma ENL concentrations are intake of lignan and lignan‐rich foods, composition and activity of intestinal microflora, antimicrobial use, nutrient intake, BMI, smoking, sex, and age. Composition and activity of the intestinal microbiota appear to be the most critical factor governing interpersonal variability in plasma ENL concentration followed by the use of antibiotics. Future studies with combined data from gut microbiota and metabolomics with food intake and life style data can be used to estimate the relative contribution of the different factors to ENL concentration in quantitative terms.