Hypothermic coagulopathy in trauma: effect of varying levels of hypothermia on enzyme speed, platelet function, and fibrinolytic activity

Comparative study of protein metabolism in neurons of layers III and V of the sensorimotor cortex was carried out in two groups of Wistar rats, which differed in learning results: "bad" (60% of population) and "good" learners (40%). It was found out that the associative neurons (layer III) were most sensitive to cognitive load. In "bad" learners, an increase in nuclear and cytoplasmic dimensions and rise in protein concentration and content took place in these neurons, while in the efferent neurons (layer V) the protein content increased only in the cytoplasm. In "good" learners, the cognitive load led to a decrease in all the cytochemical parameters in neurons of the layer III while in the neurons of the layer V the content and concentration of proteins increased both in nuclei and cytoplasm. It is suggested that the character of protein metabolism changes produced by information load can be considered as a reflection of individual peculiarities of cognitive activity, and the extent of cytochemical changes as a reflection of complicity of a cognitive task.     

Innovative circuit board level routing designs for BGA packages

Advances in the performance of electronic devices have resulted in high input/output counts both at the chip and the package level, which has led to the development of new packaging technologies that can accommodate these high counts. This paper presents and analyzes a novel method for the placement of ball grid array (BGA) bonding pads and routing wires on printed circuit boards to maximize signal density, which ultimately reduces the number of circuit board layers needed for routing. This method has been termed as the "balls shifted as needed" method and all the ball placement/trace routing designs shown in this paper are based on this method. We also present a performance metric defined as the number of balls routed out divided by the area of package footprint on the circuit board, and we compare various placement/routing schemes using this method.     

Performance of orthogonal frequency division multiplexing based M-ary quadrature amplitude modulation in asymmetrical dual-hop mixed RF-FSO transmission system

This paper investigates the performance of a dual-hop mixed relay system with radio frequency (RF) and free-space optics (FSO) communication under the effect of pointing error (PE) and atmospheric turbulence (AT). This paper considers a system where RF and FSO links are cascaded. The RF link is modeled by Nakagami-m fading, and the FSO link is modeled as gamma–gamma (G-G) fading channel. Both the channel models use orthogonal frequency division multiplexing (OFDM) with M-ary quadrature amplitude modulation (QAM). The expressions for probability density function, cumulative distribution function, signal-to-noise ratio, and ergodic capacity are derived. The moment generating function (MGF) of fading and the bit error rate (BER) of the OFDM-based M-ary QAM scheme is derived in terms of Meijer's G-function. It has been observed that, in fixed gain relay systems, the modulation scheme's BER is dominated by the SNR of the RF link. While in a variable gain relay system, the turbulence conditions of the FSO system affect the SNR and the BER of the modulation method. The feasibility of heterodyne detection and intensity modulation direct detection (IM/DD) is analyzed in terms of outage probability and ergodic capacity. The results can be used to choose the optimal modulation order and relay system for QAM-OFDM-based optical wireless systems.     

Reliability analysis of a two-unit cold standby redundant system with two operating modes

This paper considers a two unit cold standby redundant system subject to a single repair facility with exponential failure and general repair time distribution. Each unit can work in three different modes — normal, partial failure and total failure. There is a perfect switch to operate the standby unit on total failure of the operative unit. The system has been analysed to determine the reliability parameters e.g. mean time to system failure (MTSF), steady state availability, mean recurrence to a state and expected number of visits to a state, first two moments of time in transient state, by using the theory of Semi-Markov Process. Howard's reward structure has been super-imposed on the Semi-Markov Process to obtained expected profit of the system. A number of results obtained earlier are derived as particular cases.     

Effect of radiographic positioning on interpretation of cubital joint congruity in dogs

OBJECTIVE: To ascertain effects of x-ray beam centering and limb position on apparent congruity of a normal cubital joint (elbow). ANIMALS: 6 skeletally mature male Treeing Walker Coonhounds without physical, radiographic, or gross evidence of elbow abnormalities. PROCEDURE: Relative movement among humerus, radius, and ulna and measured joint space width on mediolateral and craniocaudal radiographic views was compared, using various x-ray beam centering and limb positions. RESULTS: Highest agreement and greatest certainty on subjective determination of congruity was for the flexed 90 degrees mediolateral radiographic view with the x-ray beam centered on the elbow. Distortion artifact of the proximal ulnar measurements was significant when the x-ray beam was centered on the midpoint of the radius. On the mediolateral view, the humeroradial joint space became significantly wide when the elbow was flexed. On the craniocaudal view, maximal humeroradial joint space width was obtained when the x-ray beam bisected the angle of the joint or was angled +30 degrees toward the humerus. CONCLUSIONS: Artifact distortion of joint width affected objective and subjective assessment of elbow congruity when the limb was placed in extreme flexion or extension or when the x-ray beam was not centered over the area of interest. Optimal visualization of the humeroradial joint space on the craniocaudal view was achieved when the x-ray beam bisected the angle of the elbow or was slightly angled toward the humerus. CLINICAL RELEVANCE: Elbow congruity was best assessed on the flexed 90 degrees lateral radiographic view with the x-ray beam centered on the joint.     

Toughening of bone cement using nanoparticle: The effect of solvent

Drawbacks of poly(methyl methacrylate) (PMMA)‐based bone cement as a grouting agent for in vivo fixation of orthopedic and dental implants such as considerable low mechanical strength have been improved using nanotechnology. Bone cement‐layered silicate nanocomposites have been prepared without any heat treatment in the presence of polar (dimethyl formamide, DMF) and nonpolar (benzene) solvents. Solvents have been removed completely from the bone cement after its preparation. Nanostructure is very much dependent on the solvent used for nanocomposite preparation, and benzene‐based nanocomposites are highly intercalated, whereas DMF‐based nanocomposites do not exhibit intercalation. Thermal stability of bone cement has improved in the presence of nanoclays. The relative enhanced interaction in case of benzene‐based nanocomposites has been shown through FTIR and UV–vis studies. The significant improvement in modulus and toughness of bone cement has been demonstrated in the presence of minimum amount of nanoclay for benzene‐based nanocomposites, whereas no change in modulus and reduced toughness have been observed for DMF‐based nanocomposites. The decrease of contact angle has been witnessed with increasing nanoclay concentration indicating better hydrophilic materials suitable for biomedical applications for greater cell growth. The reason for varying property enhancement in different solvents has been discussed considering the polarity effect and interactions. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Ceria (La3+, Sr2+)/Carbonates Nanocomposite Electrolytes with High Electrical Conductivity for Low‐Temperature SOFCs

A series of ceria‐based nanocomposites consisting of lanthanum and strontium codoped ceria with composition Ce_0.89La_0.07Sr_0.04O_1.925 (CL7S4) and eutectic mixture of carbonates Li₂CO₃‐Na₂CO₃ (LNCO) have been prepared by mixing nanosize powders of CL7S4 and LNCO. Samples have been characterized using differential thermal analysis, X‐ray diffraction, scanning electron microscopy combined with energy‐dispersive spectroscopy, thermal expansion, and impedance spectroscopy. A sharp increase in ionic conductivity is observed in all the composite specimens corresponding to superionic transition. Sample containing 35 wt% of carbonate shows the maximum conductivity (2.56 × 10^?1 S/cm at 500°C) with activation energy of conduction, E_a 0.23 eV.     

Adenovirus-mediated gene transfer is augmented in basilar and carotid arteries of heritable hyperlipidemic rabbits

OBJECTIVE: Regional presynaptic dopaminergic function and its regulation by dopamine agonists in different stages of PD can be measured by L-[11C]dopa and PET. In the current investigation, we studied the effects of therapeutic apomorphine on L-[11C]dopa uptake in patients with early and advanced PD. BACKGROUND: With disease progression and chronic dopamine agonist treatment, motor response complications supervene in a majority of PD patients. It is assumed that both presynaptic and postsynaptic changes in the dopaminergic system act to modify dopaminergic efficacy. METHODS: Patients with early and advanced stages of PD were included in the study. All patients were investigated twice with PET and L-[11C]dopa drug free and during a subsequent standardized therapeutic apomorphine infusion. RESULTS: Subregional analysis of the striatum showed differences in the effects of apomorphine infusion on the L-[11C]dopa influx rate in the two patient categories. In patients with early and uncomplicated PD, apomorphine infusion decreased the L-[11C]dopa influx rate. This decrease was most pronounced in the dorsal part of the putamen. In advanced PD patients, apomorphine did not affect the striatal L-[11C]dopa influx rate. CONCLUSIONS: We suggest that in mild and stable PD an upregulated presynaptic inhibitory feedback regulation, particularly in the dorsal putamen, acts to maintain congruity within the dopaminergic system in response to antiparkinsonian medication. However, this inhibitory feedback regulation is diminished with the progression of nigrostriatal degeneration and chronic dopamine agonist treatment.     

Extracellular matrix survival signals transduced by focal adhesion kinase suppress p53-mediated apoptosis

In many malignant cells, both the anchorage requirement for survival and the function of the p53 tumor suppressor gene are subverted. These effects are consistent with the hypothesis that survival signals from extracellular matrix (ECM) suppress a p53-regulated cell death pathway. We report that survival signals from fibronectin are transduced by the focal adhesion kinase (FAK). If FAK or the correct ECM is absent, cells enter apoptosis through a p53-dependent pathway activated by protein kinase C lambda/iota and cytosolic phospholipase A2. This pathway is suppressible by dominant-negative p53 and Bcl2 but not CrmA. Upon inactivation of p53, cells survive even if they lack matrix signals or FAK. This is the first report that p53 monitors survival signals from ECM/FAK in anchorage- dependent cells.