Surface immobilized zoledronate improves screw fixation in rat bone: A new method for the coating of metal implants

Previous studies show that surface immobilized bisphosphonates improve the fixation of stainless steel screws in rat tibia after 2–8 weeks of implantation. We report here about the immobilization of a potent bisphosphonate, zoledronate, to crosslinked fibrinogen by the use of another technique, i.e. ethyl-dimethyl-aminopropylcarbodiimide (EDC)/imidazole immobilization. Bone fixation of zoledronate-coated screws was compared to screws coated with crosslinked fibrinogen only and ditto with EDC/N-hydroxy-succinimide immobilized pamidronate. Fixation in rat tibia was evaluated by a pull-out test at either 2 or 6 weeks after implantation. Both bisphosphonate coatings increased the pull-out force at both time points, and zoledronate showed a significantly higher pull-out force than pamidronate. To further evaluate the new coating technique we also performed a morphometric study, focusing on the area surrounding the implant. The zoledronate coating resulted in an increased bone density around the screws compared to controls. No pronounced increase was seen around the pamidronate coated screws. Together, the results demonstrate the possibility of obtaining a significant local therapeutic effect with minute amounts of surface immobilized zoledronate.     

Stressor-Induced Increases in Circulating,but Not Colonic,Cytokines Are Related to Anxiety-like Behavior and Hippocampal Inflammation in a Murine Colitis Model

Stressor exposure increases colonic inflammation. Because inflammation leads to anxiety-like behavior, we tested whether stressor exposure in mice recovering from dextran-sulfate-sodium (DSS)-induced colitis enhances anxiety-like behavior. Mice received 2% DSS for five consecutive days prior to being exposed to a social-disruption (SDR) stressor (or being left undisturbed). After stressor exposure, their behavior was tested and colitis was assessed via histopathology and via inflammatory-cytokine measurement in the serum and colon. Cytokine and chemokine mRNA levels in the colon, mesenteric lymph nodes (MLNs), hippocampus, and amygdala were measured with RT-PCR. SDR increased anxiety-like behaviors, which correlated with serum and hippocampal IL-17A. The stressor also reduced IL-1β, CCL2, and iNOS in the colonic tissue, but increased iNOS, IFNγ, IL-17A, and TNFα in the MLNs. A network analysis indicated that reductions in colonic iNOS were related to elevated MLN iNOS and IFNγ. These inflammatory markers were related to serum and hippocampal IL-17A and associated with anxiety-like behavior. Our data suggest that iNOS may protect against extra-colonic inflammation, and when suppressed during stress it is associated with elevated MLN IFNγ, which may coordinate gut-to-brain inflammation. Our data point to hippocampal IL-17A as a key correlate of anxiety-like behavior.     

Omega-3 Index Correlates with Healthier Food Consumption in Adolescents and with Reduced Cardiovascular Disease Risk Factors in Adolescent Boys

The Omega-3 Index, a measure of long-chain omega-3 fats in red blood cell membranes, predicts heart disease mortality in adults, but its association with cardiovascular risk factors in younger populations is unknown. We determined the Omega-3 Index in adolescents participating in the Western Australian Pregnancy (Raine) Cohort, assessed associations with diet, lifestyle and socioeconomic factors, and investigated independent associations with cardiovascular and metabolic risk factors. Red blood cell fatty acid analysis was determined for 1,301 adolescents aged 13–15 years. Risk factors examined were blood pressure, fasting blood insulin and glucose concentrations, and fasting blood lipids including ratios. The mean Omega-3 Index was 4.90 ± 1.04% (range 1.41–8.42%). When compared with categories identified in adults, 15.6% of adolescents were in the high risk category (Index < 4%). Age (P < 0.01), maternal education (P < 0.01) and BMI (P = 0.05) were positively associated with the Omega-3 Index. The Index was positively associated with dietary intakes of eicosapentaenoic and docosahexaenoic acid (P < 0.01), protein (P < 0.01), omega-3 fats (P < 0.04), and food groups of fish and wholegrains (both P < 0.01), and negatively associated with intakes of soft drinks and crisps (both P < 0.01). In boys, the Omega-3 Index was independently associated with total (β = 0.06, P = 0.01) and HDL-cholesterol (β = 0.03, P = 0.01), and diastolic blood pressure (β = −0.68, P = 0.04). The predictability of the Index for the risk of cardiovascular disease later in life warrants further investigation in the adolescent population.     

Influence of Heat Treatments on Microstructure and Toughness of 9%Ni Steel

The 9%Ni low-carbon steel is applied to utilities and processes at temperatures as low as ??196 °C. However, the microstructural features play an important role on the mechanical properties. Notably, the cryogenic toughness and mechanical strength are strongly dependent on the final heat treatment. In this paper, the microstructure of a 9%Ni low-carbon steel was modified by different heat treatments. The hardness and cryogenic toughness were measured and correlated to microstructural features. The material shows a temper embrittlement with intergranular cracking and minimum cryogenic toughness after tempering around 400 °C. Austempering at 480 °C also produced very low toughness results. On the other hand, excellent cryogenic toughness was obtained with single tempering at 600 °C after quenching or normalizing. Even higher toughness was obtained with the double tempering at 670 °C/2 h plus 600 °C/2 h. The amount of reversed austenite and its morphology in the specimen quenched and tempered at 600 °C were shown in the paper.     

Robust algorithm for alignment of liquid chromatography-mass spectrometry analyses in an accurate mass and time tag data analysis pipeline

Liquid chromatography coupled to mass spectrometry (LC-MS) and tandem mass spectrometry (LC-MS/MS) has become a standard technique for analyzing complex peptide mixtures to determine composition and relative abundance. Several high-throughput proteomics techniques attempt to combine complementary results from multiple LC-MS and LC-MS/MS analyses to provide more comprehensive and accurate results. To effectively collate and use results from these techniques, variations in mass and elution time measurements between related analyses need to be corrected using algorithms designed to align the various types of data: LC-MS/MS versus LC-MS/MS, LC-MS versus LC-MS/MS, and LC-MS versus LC-MS. Described herein are new algorithms referred to collectively as liquid chromatography-based mass spectrometric warping and alignment of retention times of peptides (LCMSWARP), which use a dynamic elution time warping approach similar to traditional algorithms that correct for variations in LC elution times using piecewise linear functions. LCMSWARP is compared to the equivalent approach based upon linear transformation of elution times. LCMSWARP additionally corrects for temporal drift in mass measurement accuracies. We also describe the alignment of LC-MS results and demonstrate their application to the alignment of analyses from different chromatographic systems, showing the suitability of the present approach for more complex transformations.     

CONFECT: Conformations from an Expert Collection of Torsion Patterns

The generation of sets of low‐energy conformations for a given molecule is a central task in drug design. Herein we present a new conformation generator called CONFECT that builds on our previously published library of torsion patterns. Conformations are generated as well as ranked by means of normalized frequency distributions derived from the Cambridge Structural Database (CSD). Following an incremental construction approach, conformations are selected from a systematic enumeration within energetic boundaries. The new tool is benchmarked in several different ways, indicating that it allows the efficient generation of high‐quality conformation ensembles. These ensembles are smaller than those produced by state‐of‐the‐art tools, yet they effectively cover conformational space.     

Maximisation of the ratio of microhardness to the Young's modulus of Ti–12Mo–13Nb alloy through microstructure changes

Alloys for orthopaedic and dentistry applications require high mechanical strength and a low Young's modulus to avoid stress shielding. Metastable β titanium alloys appear to fulfil these requirements. This study investigated the correlation of phases precipitated in a Ti–12Mo–13Nb alloy with changes in hardness and the Young's modulus. The alloy was produced by arc melting under an argon atmosphere, after which, it was heat treated and cold forged. Two different routes of heat treatment were employed. Phase transformations were studied by employing X-ray diffraction and transmission electron microscopy. Property characterisation was based on Vickers microhardness tests and Young's modulus measurements. The highest ratio of microhardness to the Young's modulus was obtained using thermomechanical treatment, which consists of heating at 1000 °C for 24 h, water quenching, cold forging to reduce 80% of the area, and ageing at 500 °C for 24 h, where the final microstructure consisted of an α phase dispersed in a β matrix. The α phase appeared in two different forms: as fine lamellas (with 240 ± 100 nm length) and massive particles of 200–500 nm size.     

Influence of Impurities in Cathodic Copper on the Ductility of Copper Wires

The main characteristic of cathodic copper is its concentration of impurities because this determines the mechanical properties, i.e., ductility, of the derived copper wires. However, the results of standard mechanical tests to evaluate ductility show that there is no clear correlation between the content of impurities in the cathodes and the ductility of the copper wires. In this study, from traction tests on copper wires and observation of their fracture surfaces by means of scanning electron microscopy and energy dispersive spectroscopy, it has been concluded that the principal impurity affecting the ductility of the copper wires is oxygen, which is mainly incorporated during the melting of the cathodes and casting of the rods. In addition, to discriminate the effect of oxygen concentration in copper ductility, the used probes or wires must have the same previous deformation and must not have been annealed. When copper wires are annealed, cuprous oxide particles are also more dispersed in the matrix, and not only segregated and concentrated as occurs in the non-annealed condition, thus diminishing the mechanical fragility effect of the oxide.     

Overview of the Structural Design of World Trade Center 1, 2, and 7 Buildings

This paper summarizes the primary structural systems that comprised World Trade Center (WTC) 1, 2, and 7, which were destroyed in the terrorist attacks of September 11, 2001. There were four major structural subsystems in the towers: the exterior walls, the core, the floor system, and the hat truss. The major structural systems within WTC 7 were the foundation, exterior moment frames, floor system, interior columns, and column transfer trusses and girders. At the time of design and construction, the WTC towers were innovative in many ways, and resulted in a tremendous increase of open-plan commercial office space in downtown Manhattan. As the first of four papers, this paper summarizes the structural and passive fire protection features of each building, and focuses on the structural systems which played a critical role in the outcome of the attacks of September 11, 2001. Three companion papers address the effects of aircraft impact damage on the WTC towers and debris damage on WTC 7, the effects of fire on the three buildings, and how these events contributed to building collapse by describing the contribution of key structural systems to the overall building behavior and collapse, such as the floor systems and hat trusses in WTC 1 and WTC 2 and the floor connections around Column 79 in WTC 7.     

A method for the large-scale isolation of β-casein

A method for the large-scale isolation of β-casein from renneted skim milk was developed. The curd from renneted skim milk was dispersed in hot (?70 °C) water to inactivate residual chymosin. The heated curd was subsequently recovered by centrifugation, resuspended in water and incubated at 5 °C, during which β-casein dissociated from the curd; the suspension was centrifuged and the aqueous phase lyophilised. The isolated protein consisted mainly of β-casein, containing a minor amount of γ-caseins and traces of other caseins. Unless chymosin was fully inactivated by heating, some β-casein was hydrolysed at the Leu₁₉₂–Tyr₁₉₃ bond. The yield of β-casein increased with incubation time, up to ∼20% of the β-casein present in the milk after 24 h at 5 °C. Reducing milk pH to 5.5 or 6.0, prior to renneting, caused a high level of contamination with α_s-caseins. This isolation procedure can be easily scaled-up to an industrial process and the β-casein-depleted curd may be used for the manufacture of rennet casein or processed cheese.