Insulin-coated gold nanoparticles: a plasmonic device for studying metal-protein interactions

Insulin-capped gold nanoparticles (Au@insulin NPs) are highly sensitive towards pH and heavy metals, due to the protein coating. Au@insulin NPs aggregate and disaggregate reversibly with pH and in the presence of various heavy metal ions, which can be monitored through reversible changes in their optical properties. The sensitivity of the NPs towards different metal ions is dissimilar and depends on the coordinative properties of each specific metal ion, its valence number, concentration, and reaction time (kinetics), representing a simple tool for studying fundamental metal-protein interactions. Moreover, Au@insulin NPs are biocompatible and highly stable at high ionic strengths, due to their robust protein coating.     

Reconstructing the 3D shape and bone mineral density distribution of the proximal femur from dual-energy X-ray absorptiometry

The accurate diagnosis of osteoporosis has gained increasing importance due to the aging of our society. Areal bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA) is an established criterion in the diagnosis of osteoporosis. This measure, however, is limited by its two-dimensionality. This work presents a method to reconstruct both the 3D bone shape and 3D BMD distribution of the proximal femur from a single DXA image used in clinical routine. A statistical model of the combined shape and BMD distribution is presented, together with a method for its construction from a set of quantitative computed tomography (QCT) scans. A reconstruction is acquired in an intensity based 3D-2D registration process whereby an instance of the model is found that maximizes the similarity between its projection and the DXA image. Reconstruction experiments were performed on the DXA images of 30 subjects, with a model constructed from a database of QCT scans of 85 subjects. The accuracy was evaluated by comparing the reconstructions with the same subject QCT scans. The method presented here can potentially improve the diagnosis of osteoporosis and fracture risk assessment from the low radiation dose and low cost DXA devices currently used in clinical routine.     

Site Management of Work-in-Process Buffers to Enhance Project Performance Using the Reliable Commitment Model: Case Study

Buffers have been commonly used as a production strategy to protect construction processes from the negative impact of variability. Construction practitioners and researchers have proposed several buffering approaches for different production situations and contexts. However, these solutions have been impractical for managing buffers. To overcome this, this study proposes a new site methodology for managing work-in-process (WIP) buffer in repetitive projects, on the basis of the reliable commitment model (RCM). RCM is a decision-making tool based on lean principles, which uses statistical models to develop more reliable work plans at the operational level. RCM helps to manage WIP buffer in work plans by using site information and planning reliability indicators that result in improved project performance, such as labor productivity and process progress. A repetitive building project was used as a case study. The main finding was that labor productivity, process progress, and waiting times improved when using larger WIP buffers than those typically used among crews. This shows the potential of RCM as a practical tool to manage WIP buffer sizes and to promote the use of lean production strategies at the operational level.     

Method-of-moments formulation for the analysis of plasmonic nano-optical antennas

We present a surface integral equation (SIE) to model the electromagnetic behavior of metallic objects at optical frequencies. The electric and magnetic current combined field integral equation considering both tangential and normal equations is applied. The SIE is solved by using a method-of-moments (MoM) formulation. The SIE-MoM approach is applied only on the material boundary surfaces and interfaces, avoiding the cumbersome volumetric discretization of the objects and the surrounding space required in differential-equation formulations. Some canonical examples have been analyzed, and the results have been compared with analytical reference solutions in order to prove the accuracy of the proposed method. Finally, two plasmonic Yagi-Uda nanoantennas have been analyzed, illustrating the applicability of the method to the solution of real plasmonic problems.     

Effect of selection for growth rate on biochemical, quality and texture characteristics of meat from rabbits

Biochemical characteristics, including myosin heavy chain I (MHC-I) percentage, isocitrate dehydrogenase and aldolase activities, meat quality traits and instrumental texture properties of rabbits selected for different growth rates were studied. The animals of the control (C) group (7th generation; n=60) were raised in parallel with those of selection (S) group (21st generation; n=60). Carcass weights (1230.1 ± 19.8 and 1348.3 ± 20.1 g, for C and S, respectively) and perirenal and scapular fat content differed significantly (P<0.01) between the two groups. Water holding capacity was expressed as the percentage of pressure released water and was significantly different (P<0.05) between groups C and S (33.29% and 35.57%). MHC-I percentage and aldolase activity also differed significantly (P<0.05) between groups, group C showing higher oxidative traits than group S (MHC-I: 12.5% and 9.8%; aldolase: 597.11 and 636.83 UI/g muscle). Texture properties from the Warner-Bratzler test showed higher (P<0.001) shear firmness for loin in the S group (1.69 kg/s cm²) than in the C group (1.34 kg/s cm²). In addition, the texture profile analysis indicated that chewiness, gumminess and hardness were also higher in the S group (P<0.01). In conclusion, the results confirmed a positive effect of the selection on productive traits and a negative effect on instrumental texture properties and on the water holding capacity of the meat.     

Effect of addition of sucrose and aspartame on the compression resistance of hydrocolloids gels

The effect of adding sucrose (5–25% w/w) and aspartame (0.04–0.16% w/w) on the compression resistance of three hydrocolloid gelled systems: κ‐carrageenan, gellan gum and κ‐carrageenan/locust bean gum at three different concentrations (0.3, 0.75 and 1.2% w/w) was studied. Sucrose addition increased true rupture stress in the three‐gelled systems, this effect being stronger in gellan gels. The deformability modulus increased with sucrose concentration in gellan gels, but not in the other systems. Rupture stress and deformability modulus increased with the addition of sucrose only in the harder gels (0.75 and 1.2% w/w). The effect of sucrose addition on the true rupture strain was significant but, in general, not important, mainly for lower gum concentrations. Aspartame addition did not affect the compression parameters.     

Effects of α s1-casein (CSN1S1) and κ-casein (CSN3) genotypes on milk coagulation properties in Murciano-Granadina goats

The effects of the caprine α s1-casein (CSN1S1) polymorphisms on milk quality and cheese yield have been widely studied in French and Italian goat breeds. Much less is known about the consequences of κ-casein (CSN3) genotype on the technological and coagulation properties of goat milk. In the current study, we have performed an association analysis between polymorphisms at the goat CSN1S1 and CSN3 genes and milk coagulation (rennet coagulation time, curdling rate and curd firmness) and technological (time to cutting of curd and cheese yield) properties. In this analysis, we have included 193 records from 74 Murciano-Granadina goats (with genotypes constituted by different combinations of alleles B, E and F of the gene CSN1S1 and alleles A and B of the gene CSN3) distributed in three herds, which were collected bimonthly during a whole lactation. Data analysis, using a linear mixed model for repeated observations, revealed significant associations between CSN1S1 genotypes and the rate of the curdling process. In this way, milk from EE goats had a significantly higher curdling rate than milk from BB individuals (P<0?·05). Contrary to previous experiments performed in French breeds, cheese yield was not significantly different in BB, EE and EF goats. Moreover, we have shown that CSN3 genotype has a significant effect on the rennet coagulation time (BB>AB, P<0?·05) but not on cheese yield. No interaction between the CSN1S1 and CSN3 genotypes was observed.     

Inactivation of Salmonella enterica serovar Enteritidis on shell eggs by ozone and UV radiation

The presence of Salmonella enterica serovar Enteritidis in shell eggs has serious public health implications. Several treatments have been developed to control Salmonella on eggs with mixed results. Currently, there is a need for time-saving, economical, and effective egg sanitization treatments. In this study, shell eggs externally contaminated with Salmonella (8.0 x 10(5) to 4.0 x 10(6) CFU/g of eggshell) were treated with gaseous ozone (O3) at 0 to 15 lb/in2 gauge for 0 to 20 min. In other experiments, contaminated shell eggs were exposed to UV radiation at 100 to 2,500 microW/cm2 for 0 to 5 min. Treatment combination included exposing contaminated eggs to UV (1,500 to 2,500 microW/cm2) for 1 min, followed by ozone at 5 lb/in2 gauge for 1 min. Eggs that were (i) noncontaminated and untreated, (ii) contaminated and untreated, and (iii) contaminated and treated with air were used as controls. Results indicated that treating shell eggs with ozone or UV, separately or in combination, significantly (P < 0.05) reduced Salmonella on shell eggs. For example, contaminated eggs treated with ozone at 4 to 8 degrees C and 15 lb/in2 gauge for 10 min or with UV (1,500 to 2,500 microW/cm2) at 22 to 25 degrees C for 5 min produced 5.9- or 4.3-log microbial reductions or more, respectively, when compared with contaminated untreated controls. Combinations including UV followed by ozone treatment resulted in synergistic inactivation of Salmonella by 4.6 log units or more in about 2 min of total treatment time. Salmonella was effectively inactivated on shell eggs in a short time and at low temperature with the use of a combination of UV radiation and ozone.