Tissue-factor antigen and activity in human coronary atherosclerotic plaques

BACKGROUND: Coronary atherosclerotic-plaque thrombosis is a key event in the pathogenesis of unstable angina and myocardial infarction. Although plaque rupture or fissuring frequently occurs in atherosclerosis, only a small proportion of ruptured plaques develop thromboses. METHODS: Tissue-factor antigen and activity were measured in atherectomy samples from 50 consecutive patients with coronary artery disease (stable angina n = 19, unstable angina n = 24, and myocardial infarction n = 7). FINDINGS: Median tissue-factor antigen and activity concentrations were significantly higher in plaques from patients with unstable angina and myocardial infarction than in those from patients with stable angina (antigen: 66.1 pg/mg [interquartile range 43.8-82.5] vs 32.4 pg/mg [9.8-43.4], p = 0.0001; activity: 0.22 mU/mg [0.17-0.41] vs 0.13 mU/mg [0.05-0.16], p = 0.0004). INTERPRETATION: Tissue-factor, an initiator of the coagulation cascade, may account for the different thrombotic responses to the rupture of human coronary atherosclerotic plaques.     

Computed tomography in injuries to the respiratory system in children. The correlation with adults

INTRODUCTION: Diagnostic imaging in emergency rooms may be inadequate and delayed, which makes chest traumas in children more severe and difficult to treat. We carried out a retrospective study on adults and children who had survived major chest traumas involving the respiratory tract to assess the differences between the two age groups and the role of emergency CT. MATERIAL AND METHODS: Our series consisted of fourteen children admitted to the emergency department for various accidents. Home accidents prevailed (9/14 = 64.3%). On admission, chest radiography was performed in most cases (11/14 = 78.6%); CT was carried out in 21.4% (3/14 patients). RESULTS: Trauma involved more organs in pediatric patients (11/14 = 78.6%) and lung involvement was always associated with other types of injury, namely contusion (14/14 = 100%), pneumothorax (11/14 = 78.6%), hemothorax (10/14 = 71.4%), tear (4/14 = 28.6%). CT corrected or integrated the radiographic findings of contusion focus in 67% (8/14) and that of pneumothorax in 63.6%; both patterns cannot be demonstrated otherwise. DISCUSSION: Mixed and multiple posterior parenchymal injuries with no rib fractures prevail in young subjects because their bones and ligaments are more elastic, which may lead to trauma underestimation. Tracheobronchial ruptures and pneumomediastinum are much more severe in children than in adults. Chest plain film is often the only diagnostic tool used, despite its major technical and interpretative limitations, also because skull and abdomen are the most investigated regions. Executive limitations are stronger in childhood, increasing the margin of error and the risk of delayed treatment. CT is as cost-effective as radiography and shows even the injuries missed or poorly depicted on conventional images; CT also gives accurate information on damage severity and nature. CONCLUSIONS: Traumatic injuries are more severe in pediatric patients due to their build and to biomechanical, clinical and management factors. Spiral CT should be considered the examination of choice to be performed in the emergency department equipped also for pediatric re-animation.     

Global stabilization of the spinning top with mass imbalance

We consider the stabilization of a top with known imbalance to the sleeping motion. We first define the sleeping motion and show that it is a solution of the equations of motion of a balanced top. In the general case where the top is unbalanced, we derive two families of control laws that globally asymptotically stabilize a top with known imbalance to the sleeping motion using torque actuators. The input torque is produced by two body-fixed torque actuators in one case, and is confined to the inertial "XY-plane in the other. The control-design strategy is based on Hamilton-Jacobi-Bellman theory with zero dynamics. The result is global in the sense that the spinning top can be stabilized to the sleeping motion regardless of spin rate, and from an arbitrary initial motion that has a coning angle of up to 90^°     

Sustainability of bioethanol production from wheat with recycled residues as evaluated by Emergy assessment

An Emergy assessment study of 24 bioethanol production scenarios was carried out for the comparison of bioethanol production using winter wheat grains and/or straw as feedstock and conversion technologies based on starch (1st generation) and/or lignocellulose (2nd generation). An integrated biomass utilization system (IBUS) was used for combining the two kinds of feedstock. The crop was cultivated under four combinations of Danish soil conditions (sand or sandy loam) and crop managements (organic or conventional). For each of the production processes, two scenarios, with or without recycling of residues, were considered. Material and energy flows were assessed to evaluate the bioethanol yield, the production efficiency in terms of Emergy used compared to energy produced (transformity), and the environmental load (ELR) in terms of use of non-renewable resources. These three indicators varied among the four feedstock production scenarios to the same extent as among the three different industrial production scenarios and in each case the efficiency was lower and the use of non-renewables higher for the non-recycling system. The system most efficient for production of bioethanol (lowest transformity) and with the lowest environmental load (ELR) was bioethanol produced from grains cultivated in the organic sandy loam scenario; systems with the highest transformity and ELR were bioethanol production based on straw from conventional cultivation and without recycling of residues. The IBUS concept obtained the best bioethanol production efficiency for each cultivation system but its consumption of non-renewable resources was not optimal.     

Sensing of damage and healing in three-dimensional braided composites with vascular channels

With the rise of composite materials as replacements for traditional monolithic materials comes an increase in demand for multifunctionality. Prior studies have demonstrated the ability of an embedded, electrically percolating carbon nanotube network to respond electrically to the onset and progression of damage in composite structures. We build upon this work by incorporating healing functionality into braided composites through the use of a hollow channel resin delivery system. This study demonstrates the ability of a carbon nanotube network to sense crack filling during resin injection, thus providing the scientific basis required for sensing healing in advanced composites. With practical application in mind, a two-part healant system is employed in this study. Two methods for qualitatively assessing healing are employed and compared; these include elastic modulus/strain energy recovery and FTIR spectroscopy.     

The effect of stress invariants on ductile fracture limit in steels

It is widely accepted that damage due to plastic deformation and ductile fracture in metals greatly depends on the triaxiality level (T) of the stress tensor, but according to recent developments described in the literature, it has been observed that the fracture limit ε_f may depend also on the deviatoric parameter (X) of the stress state. In the present paper, several special fracture tests comprising tensile, torsion, flattening and bending have been devised for the specific purpose of investigating as much wide as possible region of the T, X domain. In addition, numerical simulations of each test have been set up to provide additional information whenever direct measures could not be feasible. Three steel grades for cold working applications, each characterized by two different heat treatments have been investigated in the experimental campaign.The results state that fracture limits in the ε_f - T plane can be confined between two boundary curves, characterized by the values X = 0 and X = 1. The paper proposes that this evidence is a consequence of the application of Tresca criterion for shear failure. It is furthermore theoretically derived and experimentally verified that the two limits are linked together through the material hardening behaviour. Finally, it is discussed that an asymmetry between tension and compression states could exist as a consequence of the proposed approach.     

Feasibility analysis of laser action in erbium-doped siliconwaveguides

The authors analyze the feasibility of laser action in erbium-doped silicon devices. The recent experimental results on spontaneous light emission at 1.54 μm from erbium doped silicon diodes and theoretical calculation on Bragg grating technology are used to evaluate the best scenario performances. The effects of processes-induced errors on the threshold conditions are taken into account. They show that laser action in the Er:Si system is feasible     

A high-speed differential resistor ladder

This paper describes the implementation of a novel high speed differential resistor ladder. In this paper it is shown that the novel ladder yields, theoretically, up to a sixteen fold reduction of the propagation delay with respect to the conventional differential ladder. In order to ease the design process, an accurate analytical model for the ladder INL is also derived in the paper.Simulation results, for a BiCMOS 0.25 μm technology, show that the novel ladder results in a fivefold increase of the maximum sampling frequency when employed to design an 8 bit Flash converter. A 65% higher speed is also highlighted when the ladder is employed in a Folding and Interpolating 8 bit converter.     

Sorption of humic acid on zeolitic tuff: a preliminary investigation

This work involves a study of the interaction of humic acid (HA) with zeolitic (phillipsite+chabazite) Neapolitan yellow tuff (NYT). HA sorption isotherms were carried out on untreated as well as on Li⁺-, Na⁺-, K⁺-, NH₄⁺-, Ca²⁺-, Mg²⁺-, or Ba²⁺-enriched samples. Except for the Li-enriched sample, Langmuir sorption curves fitted the experimental data, allowing the calculation of the maximum HA sorbable amount, Q_max, and the affinity constant between the sorbate and the sorbent, k. The Q_max for the untreated sample was 8512±265 mg kg⁻¹, with k=10.8±1.4 l kg⁻¹. The experimental amounts of HA taken up by the Li-enriched sample were very small (183 to 2322 mg kg⁻¹) and too scattered to be consistently fitted by any significant equation. For other cation enriched-samples, the HA-Q_max amounts ranged from 6583±205 mg kg⁻¹ for the K-treated tuff to 22 029±1065 mg kg⁻¹ for the Mg-treated tuff, whereas the k values ranged from 8.0±1.7 l kg⁻¹ for the Na-treated tuff to 81.4±17.5 l kg⁻¹ for the Ba-treated tuff. The tuff samples enriched by divalent cations took up HA in amounts larger than those observed for the untreated sample; the opposite was true for the monovalent cation-enriched samples. The HA sorption curves on monovalent cation-enriched tuff were scarcely different, within experimental variance, from those observed for the untreated sample. On the contrary, both the Q_max and the k values calculated for the HA sorption on the divalent cation-enriched samples were widely and significantly larger than those of the untreated sample, with the highest Q_max for Mg- and Ca-enriched sample, and the highest k value for the Ba-enriched one. The results demonstrate that enrichment by divalent cations enhances the ability of Neapolitan yellow tuff to take up humic acid, whereas enrichment by monovalent cations reduces it; the results also show that humic acid sorption on tuff must be regarded as a complex phenomenon, occurring as a compromise between the ability of the cations to form stable bridges with the organic matter, and, on the other hand, their specific selective sorption by the tuff.