bluuebunny/crossref_metadata_2025 huggingface dataset:
Mathematical Model of a Railway Pneumatic Brake System With Varying Cylinder Capacity Effects
Authors: Bharath S. , Nakra B. C. , Gupta K. N.
Published: March 2008

Governing equations for the analysis of pressure transient are derived from the principle of conservation of mass and momentum for a pneumatic brake system, which consists of a train pipe connected to a number of linear actuators (brake cylinders with piston displacement). The governing one-dimensional non-linear partial differential equations for the train pipe, non-linear ordinary differential equations for the brake cylinders, and second-order differential equation of motion for piston displacement are solved to determine the pressure transients in the brake system for a step change in pressure at the inlet. The governing equations are nondimensionalized and reduced to a set of ordinary nonlinear differential difference equations and integrated by standard numerical methods. The flow is considered isothermal, and the friction effects for turbulent and laminar flow are evaluated by quasi-steady state approximation. The auxiliary reservoir volume effect is also included. The results are compared with the experimental data obtained on a brake test rig.
Insect Odorant Receptors Are Molecular Targets of the Insect Repellent DEET
Authors: Ditzen Mathias , Pellegrino Maurizio , Vosshall Leslie B.
Published: March 2008

DEET (
N,N
-diethyl-meta-toluamide) is the world's most widely used topical insect repellent, with broad effectiveness against most insects. Its mechanism of action and molecular target remain unknown. Here, we show that DEET blocks electrophysiological responses of olfactory sensory neurons to attractive odors in
Anopheles gambiae
and
Drosophila melanogaster
. DEET inhibits behavioral attraction to food odors in
Drosophila
, and this inhibition requires the highly conserved olfactory co-receptor OR83b. DEET inhibits odor-evoked currents mediated by the insect odorant receptor complex, comprising a ligand-binding subunit and OR83b. We conclude that DEET masks host odor by inhibiting subsets of heteromeric insect odorant receptors that require the OR83b co-receptor. The identification of candidate molecular targets for the action of DEET may aid in the design of safer and more effective insect repellents.
Coherent Dynamics of a Single Spin Interacting with an Adjustable Spin Bath
Authors: Hanson R. , Dobrovitski V. V. , Feiguin A. E. , Gywat O. , Awschalom D. D.
Published: March 2008

Phase coherence is a fundamental concept in quantum mechanics. Understanding the loss of coherence is paramount for future quantum information processing. We studied the coherent dynamics of a single central spin (a nitrogen-vacancy center) coupled to a bath of spins (nitrogen impurities) in diamond. Our experiments show that both the internal interactions of the bath and the coupling between the central spin and the bath can be tuned in situ, allowing access to regimes with surprisingly different behavior. The observed dynamics are well explained by analytics and numerical simulations, leading to valuable insight into the loss of coherence in spin systems. These measurements demonstrate that spins in diamond provide an excellent test bed for models and protocols in quantum information.
Light-induced inhibition of respiration in DCMU-poisoned Chlorella caused by photosystem I activity
Authors: Sargent D. F. , Taylor C. P. S.
Published: March 2008

We have demonstrated that the reduced net rate of oxygen uptake observed when DCMU-poisoned Chlorella are illuminated is a result of an inhibition of respiration rather than residual photosynthetic oxygen evolution. The action spectrum of the effect demonstrates that chlorophyll a is the main photoreceptor, implicating system I of photosynthesis. Studies using PMS, which is known to stimulate cyclic photophosphorylation by photosystem I, show that the respiratory inhibition is caused by a change in the intracellular ATP/ADP balance as a result of cyclic photophosphorylation.
Host–parasite relations in mycoparasite. II. Incorporation of tritiated N-acetyl-glucosamine into Choanephora cucurbitarum infected with Piptocephalis virginiana
Authors: Manocha M. S. , Lee K. Y.
Published: March 2008

The mature spore of Choanephora cucurbitarum possesses a thick three-layered cell wall which is different from the hyphal wall. Its germination is accompanied by the formation of a thin, elastic inner layer which extends around the emerging germ tube and the growing hypha. High resolution autoradiography showed that 3H N-acetyl-glucosamine, a precursor of chitin, was incorporated preferentially in the thin inner layer of the conidial wall and also in the wall of the growing hypha. When the label was fed to the infected cells, at different intervals, 18, 24, 30 h after inoculation, grains were observed in the sheath area around the haustorium of Piptocephalis virginiana, only at 24 and 30 h after inoculation. The significance of these results in relation to the origin and composition of the haustorial sheath is discussed.
The linkage map of the second chromosome of the tomato
Authors: Butler L.
Published: March 2008

The map of chromosome 2 has been brought up to date and 33 genes are located. Three-point crosses indicate that the gene order is s ms10wv Wo Me o dil aw (v2op suf) p d m dv, with the relative order of the three genes in parentheses still to be determined. Multiple two-point crosses are reported for the other 18 genes whose linkage relationships to d, aw, and their nearest neighbor are discussed. This permits the construction of a map for these genes placing the 33 mutants in relation to the centromere. The gene dd seems to be wrongly located.The heterogeneity of some recombination values and the paucity of close linkages in the central portion of the chromosome reveal a number of problems which should be investigated. The chromosome map which has been largely constructed from material with a uniform background forms a reference point for investigating the effect of asynapsis and inversions.
Use of parenteral nutrition in patients with advanced cancer
Authors: Soo Isaac , Gramlich Leah
Published: March 2008

The purpose of this study is to describe patient-related variables in a cohort of advanced cancer patients (ACPs) enrolled in a home parenteral nutrition (HPN) program. This study reviewed the cohort of ACPs enrolled in the Northern Alberta Home Total Parenteral Nutrition Program (NAHTPNP). Thirty-eight ACPs received HPN during the study period, 24% of all patients admitted for PN. Of these, 27 (71%) were female. Mean age was 48.76 y (SD 13.8 y). Bowel obstruction was the most common indication for initiating HPN (84%, 32) and ovarian cancer was the most common malignancy (34%, 13). Patients who began HPN with a Karnofsky performance status (KPS) of greater than 50 (median of 70) were found to have a longer duration of life (median: 6 months) compared with patients who began HPN with a KPS of 50 or below (median = 50; median 3 months; p = 0.01; two-tailed). There was no difference in survival between malignancy type (p = NS). Advanced cancer is the fastest growing indication for enrollment in the HPN program. ACP demonstrated a 3% average annual increase proportionate to all indications for HPN starts, accounting for 7%–48% of HPN starts from 1999–2006. HPN is an increasingly used therapy for patients with advanced cancer, most commonly for intestinal failure in the setting of bowel obstruction. Initiation of HPN at a higher KPS was associated with a longer duration of life. Further studies are needed to validate the use of TPN in end-stage cancer patients.
TWO-STAGE BIOMETRIC AUTHENTICATION METHOD USING THOUGHT ACTIVITY BRAIN WAVES
Authors: PALANIAPPAN RAMASWAMY
Published: March 2008

Brain waves are proposed as a biometric for verification of the identities of individuals in a small group. The approach is based on a novel two-stage biometric authentication method that minimizes both false accept error (FAE) and false reject error (FRE). These brain waves (or electroencephalogram (EEG) signals) are recorded while the user performs either one or several thought activities. As different individuals have different thought processes, this idea would be appropriate for individual authentication. In this study, autoregressive coefficients, channel spectral powers, inter-hemispheric channel spectral power differences, inter-hemispheric channel linear complexity and non-linear complexity (approximate entropy) values were used as EEG features by the two-stage authentication method with a modified four fold cross validation procedure. The results indicated that perfect accuracy was obtained, i.e. the FRE and FAE were both zero when the proposed method was tested on five subjects using certain thought activities. This initial study has shown that the combination of the two-stage authentication method with EEG features from thought activities has good potential as a biometric as it is highly resistant to fraud. However, this is only a pilot type of study and further extensive research with more subjects would be necessary to establish the suitability of the proposed method for biometric applications.
AN EXPERIMENTAL STUDY OF HYBRIDIZING CULTURAL ALGORITHMS AND LOCAL SEARCH
Authors: NGUYEN TRUNG THANH , YAO XIN
Published: March 2008

In this paper the performance of the Cultural Algorithms-Iterated Local Search (CA-ILS), a new continuous optimization algorithm, is empirically studied on multimodal test functions proposed in the Special Session on Real-Parameter Optimization of the 2005 Congress on Evolutionary Computation. It is compared with state-of-the-art methods attending the Session to find out whether the algorithm is effective in solving difficult problems. The test results show that CA-ILS may be a competitive method, at least in the tested problems. The results also reveal the classes of problems where CA-ILS can work well and/or not well.
INVESTIGATION OF SEGMENTAL CARPAL TUNNEL PRESSURE IN PATIENTS WITH IDIOPATHIC CARPAL TUNNEL SYNDROME — IS IT NECESSARY TO RELEASE THE DISTAL APONEUROTIC PORTION OF THE FLEXOR RETINACULUM IN ENDOSCOPIC CARPAL TUNNEL RELEASE SURGERY?
Authors: Murata Keiichi , Yajima Hiroshi , Maegawa Naoki , Hattori Koji , Takakura Yoshinori
Published: March 2008

Segmental carpal tunnel pressure was measured in 12 hands of 11 idiopathic carpal tunnel syndrome patients before and after two-portal endoscopic carpal tunnel release. We aimed to determine at which part of the carpal tunnel the median nerve could be compressed, and to evaluate whether carpal tunnel pressure could be reduced sufficiently at all segments of the carpal tunnel after the surgery. Pressure measurements were performed using a pressure guide wire. The site with the highest pressure corresponded to the area around the hamate hook; the pressure in the area distal to the flexor retinaculum could be pathogenically high (more than 30 mmHg) before the surgery. The two-portal endoscopic carpal tunnel release achieved sufficient pressure reduction in all segments of the carpal tunnel when the flexor retinaculum and the fibrous structure between the flexor retinaculum and the palmar aponeurosis were completely released.
MALUNITED FRACTURES OF THE DISTAL RADIUS TREATED WITH CORRECTIVE OSTEOTOMY USING VOLAR LOCKING PLATE AND A CORTICOCANCELLOUS BONE GRAFT FOLLOWING IMMEDIATE MOBILISATION
Authors: Osada Denju , Kamei Shuzo , Takai Morimitsu , Tomizawa Kazuo , Tamai Kazuya
Published: March 2008

We describe our experience of using a volar locking plate for corrective osteotomy and bone grafting combined with early mobilisation in the treatment of distal radius malunions. Corrective osteotomy of the distal radius was performed through a volar approach, and fixated by a volar locking plate associated with corticocancellous iliac bone grafting in three patients aged 16, 71 and 75 years. Two patients had had volarly displaced malunion and one dorsally displaced malunion. Wrist motin was started immediately after surgery. The average follow-up was 15 months (range, 12–20 months). All osteotomies healed at an average 5.7 weeks post-operatively, resulting in a total arc of wrist motion of 133°, forearm rotation of 167°, and grip strength of 70% of that of the contralateral side. This treatment method proved to be effective and safe.
ISOLATED VOLAR DISLOCATION OF THE FIFTH CARPOMETACARPAL JOINT: A CASE REPORT
Authors: Nakayama Masanori , Horiuchi Yukio , Kawashima Hidekazu
Published: March 2008

Isolated volar dislocation of the fifth carpometacarpal joint is a very rare injury. We present two cases of isolated volar dislocation of the fifth carpometacarpal joint treated successfully with percutaneous skeletal fixation.
IDIOPATHIC CALCINOSIS CUTIS IN FINGERTIP TREATED WITH OCCLUSIVE DRESSING USING ALUMINUM FOIL: A CASE REPORT
Authors: Sato Kazuki , Nakamura Toshiyasu , Toyama Yoshiaki , Ikegami Hiroyasu , Kameyama Kaori , Takayama Shinichiro
Published: March 2008

Calcium deposition in the skin, known as calcinosis cutis, is an uncommon disorder caused by an abnormal deposit of calcium phosphate in the skin. We report a case of idiopathic calcinosis cutis in fingertip treated with surgical excision followed by the occlusive dressing using aluminum foil, and obtained significant pain relief and round-shaped fingertip which looked normal.
INTRA-ARTICULAR RADIAL HEAD FRACTURE IN A CHILD WITH AN OPEN PHYSIS: A CASE REPORT
Authors: Moriya Koji , Maki Yutaka , Kouda Hisao
Published: March 2008

Fractures of the proximal end of the radius in children are uncommon. A case of fracture through the articular surface of the radial head (Salter–Harris type IV) in a 12-year-old boy is presented. Our paper recommends bone peg fixation in the treatment of Salter–Harris (S–H) type III or IV injuries in nearly skeletally mature.
ON TRUTH, UNCERTAINTY, EQUILIBRIUM AND HARMONY — A TAXONOMY FOR YINYANG SCIENTIFIC COMPUTING
Authors: ZHANG WEN-RAN , WANG PAUL P. , PEACE KARL E. , ZHAN JUSTIN , ZHANG YAN-QING
Published: March 2008

Although modern scientific and technological advances derive computational power primarily from the classical evidence-based bottom-up cognition as founded by Greek philosopher Aristotle in his philosophy of science with a bivalent logic, the classical cognition, however, has met stiff challenges during the last few decades because of uncertainty faced by many new scientific endeavors. The holistic top-down nature of nanotechnology and brain modeling are just two of many examples. This new development points to the need for a critical review of the historical origins and distinctions of both top-down and bottom-up cognitions. This paper reviews the philosophy of science as founded by Aristotle (300BC), the Platonic realism as founded by Aristotle's teacher Plato (400BC-300BC), and the YinYang philosophy as founded by the ancient Chinese philosopher Laozi (or Laotze) (600BC). It is suggested that the long-standing unsettled dispute between Aristotle and Plato features a major source of uncertainty for both logic and mathematics. The authors hence propose a number of controversial philosophical and logical issues for debate. We advocate YinYang as an inspiration and unifying force for both top-down inductive and bottom-up deductive reasoning. We attempt to use an equilibrium-based YinYang bipolar dynamic logic (BDL) to bridge the gap between Aristotle and Plato as well as between logic and mathematics. Furthermore, we present a taxonomy for YinYang scientific computing with a classification of logical and statistical models for further discussion; we suggest that YinYang can be used as a catalyst for resolving certain "terminological difficulties" regarding truth, polarity, intuitionism, para-consistency, and fuzziness for equilibrium and harmony. A number of critical points are enumerated and discussed. An open challenge is posted.
SOIL-PILE INTERACTION DURING LIQUEFACTION-INDUCED LATERAL SPREAD
Authors: GOH S. H. , O'ROURKE T. D.
Published: March 2008

This paper describes a numerical model for the analysis of foundation piles subjected to large lateral ground deformation triggered by liquefaction. The model involves the use of p-y curves, but avoids the empiricism associated with the selection of degradation coefficients or reduction factors. To obtain a proper p-y characterization of the reaction between laterally deformed liquefied soil and an embedded pile, triaxial extension is recognized as the most appropriate analogue for the loading conditions. A suite of undrained triaxial extension tests was carried out using Nevada sand to establish the relevant strength and deformation parameters. Using the material parameters obtained from these tests, 2D FLAC analyses were performed to develop strain-softening p-y curves. Application of these p-y curves to the analyses of centrifuge experiments involving lateral spread effects on piles yields good agreement between the computed and measured responses. The strain-softening model provides excellent predictions of the measured peak and residual moments. Furthermore, the computed soil pressure diagrams agree well with the recommendations made by the Japan Road Association, which were calibrated using case histories from the 1995 Kobe earthquake. The same p-y curves were applied to the analysis of a field problem involving an actual pile foundation subjected to lateral spread effects during the 1964 Niigata earthquake.
Proton Conductivity and Micro-morphology of Nafion Fuel Cell Membranes Determined by Electrochemical Atomic Force Microscopy
Authors: Aleksandrova Elena , Hiesgen Renate , Roduner Emil
Published: March 2008

The proton conductivity of a Nafion 112 membrane is measured with a resolution of ca. 10 nm using Electrochemical Atomic Force Microscopy. The observations are compared with the Gierke model of the micro-morphology due to phase separation of the hydrophobic polymer backbone and the hydrophilic pendant groups. The results demonstrate a highly inhomogeneous conductivity distribution which is attributed to the limited connectivity of hydrophilic domains. A pronounced peak was found in histograms representing the number of conductive areas with a certain current. We suggest that the measured current significantly depends on the formation of a continuous network in the membrane, so that the same conductivity can be measured at all pore exits. These pore exits to some extent seem to be quantized in size, even though they are of irregular shape.
Miniband Formation in Superlattices of Colloidal Quantum Dots and Conductive Polymers
Authors: Sun Ke , Li Yang , Stroscio Michael A. , Dutta Mitra
Published: March 2008

We study the bound states and quasi-bound states in a 3- dimensional superlattice formed by an alternating structure of colloidal quantum dots and conductive polymers. Calculations of transmission coefficient of injected holes and electrons vs. their energy, by means of a transfer-matrix implementation1, are performed. In this study, TiO2, CdSe, CdS and GaN quantum dots are investigated as in a 1-dimensional array of ten quantum dots, interspersed in conductive polymers PDCTh and MEH- PPV. These compound semiconductor quantum dots are selected in view of their potential applications in single-photon detectors, solar cells, etc.2,3 Discrete energy levels in such periodic nanoscale structures form minibands;4 moreover, for injection energies close to the barrier height, these minibands have substantial width and large transmission coefficients implying that they may be used to improve the charge transport efficiency in previously-identified c lasses of electronic and optoelectronic devices incorporating ensembles of colloidal quantum dots embedded in conductive polymers.
Synthesis and Application of Titanate Nanotubes in Lactate Electrochemical Biosensor
Authors: Yang Mingli , Wang Jin , Li Huaqing , Wu Nianqiang Nick N.
Published: March 2008

Hydrogen titanate (H2Ti3O7) nanotubes (TNTs) have been synthesized by a one-step hydrothermal reaction of TiO2 with NaOH. A reagentless amperometric lactate oxidase (LOx)-based biosensor has been constructed for lactate detection. In the biosensor, the LOx enzyme is immobilized on to the TNTs that are multiwall hollow tubes with two open ends with diameter of 15-20 nm. The biosensor exhibits a sensitivity of 4 µA/mM and a linear response range up to 14 mM lactic acid. The TNTs facilitate direct electron transfer between the active centers of LOx and the gold electrode.
Modeling of Crevice Corrosion of Fe - Cr Alloys in Chloride Media
Authors: Stroe Mioara , Oltra Roland , Vuillemin Bruno
Published: March 2008

Crevice corrosion of stainless steel in chloride media was investigated based on a 11 species model. The role of parameters like pH inside the crevice, external potential, chloride concentration of the bulk solution and crevice geometry was studied. A thermodynamic criterion for arrest / propagation of the crevice corrosion was used in order to identify the conditions for which the localised corrosion can propagate. This study shows that there is a combination of crevice geometry and potential for which the crevice is not blocked by precipitates and thus the corrosion can proceed.
Growth and Characterization of Vertically Aligned Densely Packed TiO2 Nanocrystals on Sapphire(100) via Metal-Organic Chemical Vapor Deposition
Authors: Chen C. A. , Korotcov A. , Chen Y.M. , Huang Ying-Sheng , Tsai D. S. , Tiong K. K. , Liao P.C.
Published: March 2008

Vertically aligned densely packed anatase- and rutile-phase TiO2 nanocrystals (NCs) have been grown by metal-organic chemical vapor deposition (MOCVD) on sapphire (SA)(100) substrates under different conditions, using titanium-tetraisopropoxide (Ti(OC3H7)4) as a source reagent. The surface morphology, structural and spectroscopic properties of the as-deposited NCs were characterized in detail using field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffractometry (XRD) and micro-Raman scattering. FESEM and TEM micrographs reveal the growth of vertically aligned NCs on SA(100) substrates. The XRD results indicate that the anatase- and rutile-TiO2 NCs are, respectively, (110) and (001) oriented on SA(100). Raman spectra show that pure anatase- and rutile- phase have been deposited. The roles of different growth conditions in the formation of different phases of the vertically aligned TiO2 NCs are studied and the probable mechanisms have been discussed.
Zinc Composite Layers, Incorporating Polymeric Nano-aggregates: Surface Analysis and Electrochemical Behavior.
Authors: Koleva Dessislava , Zhang Xiaolong , Petrov Petar , Boshkov Nikolai , Van Breugel Klaas , De Wit J.H.W. , Mol J.M.C. , Tsvetkova Neli
Published: March 2008

This study reports on a comparative investigation of the corrosion behavior of zinc (Zn) and nano-composite zinc (ZnC) galvanic layers in 5% NaCl solution. The metallic matrix of the ZnC layers incorporates nano-sized, stabilized polymeric aggregates, formed from the amphiphilic tri-block co-polymer: poly(2-hydroxyethyl methacrylate) - poly (propylene oxide - poly (2-hydroxyethyl methacrylate) (PHEMA15PPO34PHEMA15). The main objective was to evaluate the electrochemical properties and surface characteristics of both coatings, thus further to investigate if the nano-composite layers will have better corrosion resistance, compared to pure galvanic zinc. The electrochemical behavior, investigated by Impedance spectroscopy (EIS) and Scanning vibrating electrode technique (SVET), supported by surface analysis, using Atomic-force microscopy (AFM) and Scanning electron microscopy (SEM), reveals higher corrosion resistance and consequently better performance of the nano-composite layers, compared to pure galvanic zinc. The mechanism of incorporation of the polymeric nano-aggregates in the coating and their influence on the barrier properties of the composite layers are also briefly discussed.
Investigation of Effect of Germanium on the Crystallization Process of Hafnium Aluminum Oxide Matrix
Authors: Zheng F , Choi W.K. , Chew H.G. , Chan L.
Published: March 2008

Germanium (Ge) nanocrystals have been successfully synthesized in the hafnium aluminum oxide (HfAlO) matrix via co-sputtering and furnace annealing. The crystallization process of the HfAlO film has been studied using a combination of Raman spectroscopy, transmission electron microscopy, secondary ions mass spectrometry and X-Ray diffraction techniques. It was found that 800{degree sign}C is the ideal annealing temperature for synthesis of Ge nanocrystals in HfAlO matrix. A higher the annealing temperature will result in significant Ge outdiffusion and thus no formation of the nanocrystals. In addition, for the sample with relatively high Ge content (~23.3%) in the HfAlO matrix, a noteworthy Ge outdiffusion and the crystallization of the film were observed even upon the annealing at 800{degree sign}C. The crystallographic phase of the film was found to favor the orthorhombic phase.
EIS Study of Soil Corrosivity
Authors: Silva Sabrina , Dick Luís Frederico P.
Published: March 2008

The corrosivity of soils was investigated by EIS. Three soil samples have collected along existing pipelines. All measurements show that the RH variation modifies the impedance response. Two times constants are found in the impedance spectra. One time constant has been attributed to the electrode-soil interface (low frequency) and the other one to the bulk effects. An equivalent electrical circuit is then proposed to fit experimental data. The granularity of soils affects the impedance spectrum. The intercept between the resistance spectrum line and real axis was inversely proportional to the specific surface area.
A "Photochemical Corrosion Diode" Model Depicting Galvanic Corrosion in Metal-Matrix Composites Containing Semiconducting Constituents
Authors: Ding Hongbo , Hihara Lloyd H.
Published: March 2008

A modified photochemical-diode (PD) model, designated as a photochemical-corrosion-diode (PCD) model, was proposed for interpreting galvanic corrosion in metal-matrix composites (MMCs) containing semiconducting constituents. The characteristics of the PCD model were introduced through direct comparison with that of the PD model. The PCD model was then used to interpret galvanic corrosion in SiC-reinforced Al-MMCs. The PCD model and the photoelectrochemical experiments on both Al/SiC MMCs and monolithic SiC predicted that solar irradiation may affect the corrosion of the Al/SiC MMCs, corroborating well with field experiments.
Serum response factor neutralizes Purα- and Purβ-mediated repression of the fetal vascular smooth muscle α-actin gene in stressed adult cardiomyocytes
Authors: Zhang Aiwen , David Jason J. , Subramanian Sukanya V. , Liu Xiaoying , Fuerst Matthew D. , Zhao Xue , Leier Carl V. , Orosz Charles G. , Kelm Robert J. , Strauch Arthur R.
Published: March 2008

Mouse hearts subjected to repeated transplant surgery and ischemia-reperfusion injury develop substantial interstitial and perivascular fibrosis that was spatially associated with dysfunctional activation of fetal smooth muscle α-actin (SMαA) gene expression in graft ventricular cardiomyocytes. Compared with cardiac fibroblasts in which nuclear levels of the Sp1 and Smad 2/3 transcriptional-activating proteins increased markedly after transplant injury, the most abundant SMαA gene-activating protein in cardiomyocyte nuclei was serum response factor (SRF). Additionally, cardiac intercalated discs in heart grafts contained substantial deposits of Purα, an mRNA-binding protein and known negative modulator of SRF-activated SMαA gene transcription. Activation of fetal SMαA gene expression in perfusion-isolated adult cardiomyocytes was linked to elevated binding of a novel protein complex consisting of SRF and Purα to a purine-rich DNA element in the SMαA promoter called SPUR, previously shown to be required for induction of SMαA gene transcription in injury-activated myofibroblasts. Increased SRF binding to SPUR DNA plus one of two nearby CArG box consensus elements was observed in SMαA-positive cardiomyocytes in parallel with enhanced Purα:SPUR protein:protein interaction. The data suggest that de novo activation of the normally silent SMαA gene in reprogrammed adult cardiomyocytes is linked to elevated interaction of SRF with fetal-specific CArG and injury-activated SPUR elements in the SMαA promoter as well as the appearance of novel Purα protein complexes in both the nuclear and cytosolic compartments of these cells.
Mechanical behavior of the quadriceps femoris muscle tendon unit during low-load contractions
Authors: Finni Taija , Havu Marko , Sinha Shantanu , Usenius Jussi-Pekka , Cheng Sulin
Published: March 2008

We examined the relationships between morphology and muscle-tendon dynamics of the quadriceps femoris muscle of 11 men using velocity-encoded phase-contrast magnetic resonance imaging (MRI). Thigh muscle electromyography and joint range of motion were first measured outside the MRI scanner during knee extension-flexion tasks that were performed at a rate of 40 times/min with elastic bands providing peak resistance of 5.2 kp (SD 0.4) to the extension. The same movement was repeated inside the MRI scanner bore where tissue velocities and muscle morphology were recorded. The average displacement in the proximal and distal halves of the rectus femoris and vastus intermedius aponeuroses was different ( P = 0.049), reflecting shortening (1.6%), but the tensile strain along the length of the aponeuroses was uniform. The aponeurosis behavior varied among individuals, and these individual patterns were best explained by the differences in relative cross-sectional area of rectus femoris to vastus muscles ( r = 0.71, P = 0.014). During dynamic contraction, considerable deformation of muscles in the axial plane caused an anatomic measure such as muscle thickness to change differently (decrease or increase) in different sites of measurement. For example, when analyzed from the axial images, the vastus lateralis thickness did not change ( P = 0.946) in the frontal plane through femur but increased in a 45° oblique plane between the frontal and sagittal planes ( P = 0.004). The present observations of the heterogeneity and individual behavior emphasize the fact that single-point measurements do not always reflect the overall behavior of muscle-tendon unit.
Combined lapatinib and cetuximab enhance cytotoxicity against gefitinib-resistant lung cancer cells
Authors: Kim Hwang-Phill , Han Sae-Won , Kim Sung-Hak , Im Seock-Ah , Oh Do-Youn , Bang Yung-Jue , Kim Tae-You
Published: March 2008

Although non-small cell lung cancer (NSCLC) cells with somatic mutations in their epidermal growth factor receptors (EGFR) initially show a dramatic response to tyrosine kinase inhibitor (TKI), these cells eventually develop resistance to TKI. This resistance may be caused by a secondary T790M mutation in the EGFR tyrosine kinase, which leads to the substitution of methionine for threonine in 790. In this study, we show that a combination of lapatinib and cetuximab overcomes gefitinib resistance in NSCLC with the T790M mutation. We observed that T790M lung cancer cells were resistant to gefitinib, and Stat3 was persistently activated in the resistant cells. A reversible EGFR and HER2 TKI, lapatinib, decreased Stat3 activation by blocking heterodimerization of EGFR and HER2, which led to a modest increase in the inhibitory effect on gefitinib-resistant T790M cells. In addition to lapatinib, the anti-EGFR antibody, cetuximab, induced down-regulation of EGFR and apoptotic cell death in T790M cells. Finally, combined lapatinib and cetuximab treatment resulted in significantly enhanced cytotoxicity against gefitinib-resistant T790M cells in vitro and in vivo. Taken together, these data suggest that treatment with a combination of lapatinib and cetuximab, which induces dimeric dissociation and EGFR down-regulation, appears to be an effective strategy for treatment of patients with EGFR TKI-resistant NSCLC. [Mol Cancer Ther 2008;7(3):607–15]
Antiangiogenic effect of gemcitabine following metronomic administration in a pancreas cancer model
Authors: Laquente Berta , Lacasa Cristina , Ginestà Mireia M. , Casanovas Oriol , Figueras Agnès , Galán Maica , Ribas Ignacio García , Germà Josep Ramon , Capellà Gabriel , Viñals Francesc
Published: March 2008

Gemcitabine shows a marked antitumor effect as a result of its cytotoxic action toward proliferative cells. In this article, we aim to investigate the potential antitumor and antiangiogenic effect of gemcitabine following a metronomic schedule that involves the regular administration of cytotoxic drugs at doses lower than standard treatment. In vitro results showed that human endothelial cells are more sensitive to gemcitabine (IC50 3 nmol/L) than pancreatic tumor cells (IC50 20 nmol/L). For in vivo studies, we used an orthotopic implantation model of human pancreatic carcinoma in nude mice. Gemcitabine was administered i.p. following a low-dose schedule (1 mg/kg/d for a month) and compared with the conventional schedule (100 mg/kg days 0, 3, 6, and 9 postimplantation). Metronomic treatment effect on established tumor was equivalent to standard administration. The measure of CD31 endothelial marked area allowed us to show an in vivo antiangiogenic effect of this drug that was further enhanced by using metronomic administration. This effect correlated with an induction of thrombospondin-1, a natural inhibitor of angiogenesis. Our results allow us to hypothesize that, in addition to a direct antiproliferative or cytotoxic antiendothelial cell effect, a secondary effect involving thrombospondin-1 induction might provide an explanation for the specificity of the effects of metronomic gemcitabine treatment. [Mol Cancer Ther 2008;7(3):638–47]
Hepatocellular carcinoma cell-specific peptide ligand for targeted drug delivery
Authors: Lo Albert , Lin Chin-Tarng , Wu Han-Chung
Published: March 2008

Hepatocellular carcinoma is the fourth leading cause of cancer death worldwide. Novel treatment strategies derived from increased knowledge of molecular oncology are constantly being developed to cure this disease. Here, we used phage display to identify a novel peptide (SP94), which binds specifically to hepatocellular carcinoma cells. In vitro, the phage clone PC94 was shown to bind to hepatocellular carcinoma cell lines by ELISA and flow cytometry analysis. In vivo, PC94 homed specifically to tumor tissues but not to normal visceral organs in severe combined immunodeficient mice bearing human hepatocellular carcinoma xenografts. This homing ability could be competitively inhibited by synthetic peptide, SP94. Immunohistochemical staining confirmed that PC94 localized to tumor tissues and that it could not be detected in SP94-competed tumor tissues. In addition, PC94 recognized the tumor tissue but not nontumor tissue in surgical specimens from hepatocellular carcinoma patients, with a positive rate of 61.3% (19 of 31). With the conjugation of SP94 and liposomal doxorubicin, the targeted drug delivery system enhanced the therapeutic efficacy against hepatocellular carcinoma xenografts through enhanced tumor apoptosis and decreased tumor angiogenesis. Our results indicate that SP94 has the potential to improve the systemic treatment of patients with advanced hepatocellular carcinoma. [Mol Cancer Ther 2008;7(3):579–89]
Engineering Biocatalysts for Production of Commodity Chemicals
Authors: Shanmugam K.T. , Ingram L.O.
Published: March 2008

Lignocellulosic biomass is an attractive alternate to petroleum for production of both fuels and commodity chemicals. This conversion of biomass would require a new generation of microbial biocatalysts that can convert all the sugars present in the biomass to the desired compounds. In this review, the critical factors that need to be considered in engineering such microbial biocatalysts for cost-effective fermentation of sugars are discussed with specific emphasis on commodity chemicals such as lactic acid, succinic acid and acetic acid.
Technological Options for Biological Fuel Ethanol
Authors: Vertès Alain A. , Inui Masayuki , Yukawa Hideaki
Published: March 2008

The current paradigm to produce biotechnological ethanol is to use the yeast Saccharomyces cerevisiae to ferment sugars derived from starch or sugar crops such as maize, sugar cane or sugar beet. Despite its current success, the global impact of this manufacturing model is restricted on the one hand by limits on the availability of these primary raw materials, and on the other hand by the maturity of baker’s yeast fermentation technologies. Revisiting the technical, economic, and value chain aspects of the biotechnological ethanol industry points to the need for radical innovation to complement the current manufacturing model. Implementation of lignocellulosic materials is clearly a key enabler to the billion-ton biofuel vision. However, realization of the full market potential of biofuels will be facilitated by the availability of an array of innovative technological options, as the flexibility generated by these alternative processes will not only enable the exploitation of heretofore untapped local market opportunities, but also it will confer to large biorefinery structures numerous opportunities for increased process integration as well as optimum reactivity to logistic and manufacturing challenges. In turn, all these factors will interplay in synergy to contribute in shifting the economic balance in favor of the global implementation of biotechnological ethanol.
Concerns, Expectations and Perception Regarding Stature, Physical Appearance and Psychosocial Functioning before and during High-Dose Growth Hormone Treatment of Short Pre-pubertal Children Born Small for Gestational Age
Authors: Lagrou K. , Froidecoeur C. , Thomas M. , Massa G. , Beckers D. , Craen M. , de Beaufort C. , Rooman R. , François I. , Heinrichs C. , Lebrethon M.C. , Thiry-Counson G. , Maes M. , De Schepper J.
Published: March 2008

Background/Aims: Few data are available about parental concerns and psychosocial functioning of young children born small for gestational age (SGA) treated with growth hormone (GH). The present study focused on the perception of short stature and the concerns and expectations of the parents regarding GH treatment. Methods: Forty prepubertal short SGA children, randomized into a GH-treated and a GH-untreated group, and their parents were evaluated by a questionnaire and a semi-structured interview at start and after 2 years of follow-up. Results: Before start, 85% of the parents were concerned about short stature, 76% expected an increase in adult height of ≧10 cm and 81% expected a positive impact on well-being. Half of the parents expressed fears regarding GH treatment. After 2 years, more parents of treated children reported obvious growth and physical changes, and fewer parents reported teasing because of short stature. An improvement of well-being was reported by half of the parents of treated and untreated children. Fears about GH treatment disappeared almost completely. Conclusion: The perspective of GH treatment induced major adult height expectations. In treated children, the physical effects of GH treatment became obvious, teasing because of short stature decreased and initial concerns about short stature and GH therapy decreased.
Physical Effects of Short-Term Recombinant Human Growth Hormone Administration in Abstinent Steroid Dependency
Authors: Graham Michael R. , Baker Julien S. , Evans Peter , Kicman Andrew , Cowan David , Hullin David , Thomas Non , Davies Bruce
Published: March 2008

Background/Aims: Recombinant human growth hormone (rhGH) as opposed to cadaver pituitary GH is misused for physical improvement. Six days’ rhGH administration, in abstinent anabolic-androgenic steroid dependents, was compared with controls. Method: Male subjects (n = 48) were randomly divided into two groups: (1): control group (C), n = 24, mean ± SD, age 32 ± 11 years, height 1.8 ± 0.06 m; (2): rhGH-using group (0.058 IU·kg–1·day–1) (GH), n = 24, mean ± SD, age 32 ± 9 years, height 1.8 ± 0.07 m. Physiological measurements included anthropometry, strength, power and peak oxygen uptake (VO2 peak). Biochemical measurements included haemoglobin, packed cell volume, glucose, sodium, potassium, urea, creatinine, total protein, albumin, thyroid function, testosterone, prolactin, cortisol, GH and insulin-like growth factor-I (IGF-I). Results: Strength, peak power output and IGF-I significantly increased and total protein, albumin and free tetra-iodothyronine significantly decreased compared to controls (p < 0.05) and within the GH group (p < 0.017). Fat-free mass index and VO2 peak significantly increased, while body fat and thyroid-stimulating hormone significantly decreased within the GH group (p < 0.017). Conclusions: Short-term rhGH increased strength and power. Of therapeutic value is the possibility that muscle bulk and strength could be increased in patients with muscle-wasting conditions.
Familial Glucocorticoid Deficiency Type 1 due to a Novel Compound Heterozygous MC2R Mutation
Authors: Mazur Artur , Koehler Katrin , Schuelke Markus , Skunde Mandy , Ostański Mariusz , Huebner Angela
Published: March 2008

Objective: Description of the clinical, biochemical and genetic features of a Polish patient with familial glucocorticoid deficiency. Methods: Detailed clinical investigation, hormonal analysis and sequencing of the coding region of the melanocortin 2 receptor (MC2R) gene in this patient. Results: We report on a 3-month-old boy with familial glucocorticoid deficiency who presented at the age of 3 months with skin hyperpigmentation, muscle weakness, mild jaundice and constipation. Hormonal analyses revealed high ACTH and TSH serum concentrations, low serum cortisol concentration along with normal blood electrolytes. On hydrocortisone supplementation, the disease symptoms disappeared and the child recovered completely. His physical and mental development progresses normally. Genetic analysis disclosed a novel compound heterozygous MC2R mutation p.Leu46fs and p.Val49Met. Conclusion: The heterozygous p.Leu46fs mutation adds to the small number of MC2R nonsense mutations and is the first frameshift mutation within the first transmembrane domain of the receptor. According to molecular modeling the Val49Met mutation results in a structural change of the first transmembrane domain and in a potential novel interaction of the transmembrane domains I and VII.
Possible Role of Meckel’s Scan Fused with SPECT CT Imaging: Unraveling the Cause of Abdominal Pain and Obscure-Overt Gastrointestinal Bleeding
Authors: Turgeon D.Kim , Brenner Darren , Brown Richard K.J. , DiMagno Matthew J.
Published: March 2008

A 27-year-old male presented with recurrent abdominal pain and high volume hematochezia despite undergoing extensive testing and a right hemicolectomy 3 years prior for a linear bleeding ulceration in the ascending colon. Studies at the University of Michigan included esophagogastroduodenoscopy (EGD), colonoscopy and video capsule endoscopy (VCE), revealing an arteriovenous malformation (AVM) in the terminal ileum. He was hospitalized for recurrent symptoms. His presentation suggested a small bowel source of obscure-overt GI bleeding based on prior non-diagnostic colonoscopy and EGD and a bilious nasogastric lavage. Tagged red blood cell scan localized bleeding to the right lower quadrant. Colonoscopy showed fresh blood in the terminal ileum without a clear source. Angiography showed no evidence of bleeding or terminal ileal AVM. A novel Meckel’s scan fused with SPECT imaging showed focal uptake in the terminal ileum. The patient underwent Meckel’s diverticulectomy with sparing of adjacent bowel and has remained asymptomatic for 19 months. This case illustrates that patients with obscure-overt GI bleeding require a step-wise multi-modality diagnostic work-up. Because Meckel’s scans are false-positive in 28% of adults, Meckel’s scan fused with SPECT imaging may offer an approach to refine diagnostic accuracy of either scan alone, but requires further investigation. Exploratory laparotomy should be reserved as a last option and is best performed with intraoperative endoscopy.
Liver Involvement with Acute Myeloid Leukemia
Authors: Mathews Emily , Laurie Timothy , O’Riordan Kenneth , Nabhan Chadi
Published: March 2008

Liver involvement with acute myeloid leukemia (AML) is rarely reported. The majority of published cases suggest a cholestatic picture and obstructive jaundice at presentation. On the contrary, our patient presented with transaminitis without cholestasis. Elevated liver function tests persisted in our patient despite cholecystectomy; however, they normalized with chemotherapy administration, suggesting that AML was the causative effect of the hepatitis-like picture. Our review of the literature revealed that most reported cases of AML with liver involvement had short-lived remissions and an overall ominous prognosis. In our opinion, patients who have liver involvement with AML should be offered alternative investigational therapies with a low hepatic toxicity profile.
Characterization of Everyday Functioning in Mild Cognitive Impairment: A Direct Assessment Approach
Authors: Giovannetti Tania , Bettcher Brianne Magouirk , Brennan Laura , Libon David J. , Burke Marykate , Duey Katia , Nieves Christine , Wambach Denene
Published: March 2008

Aims: To evaluate the degree and pattern of functional difficulties in mild cognitive impairment (MCI) via direct observation of everyday task performance. Methods: MCI (n = 25), mild Alzheimer’s disease (AD; n = 25), and control (n = 18) participants performed three everyday tasks of increasing complexity. Results: Although caregivers reported no functional difficulties in MCI, direct observation measures of overall impairment and total errors showed MCI participants performed worse than controls, but better than AD participants, even on simple tasks. MCI and control participants exhibited significantly more difficulty performing steps accurately (i.e. commission errors) than completing task steps (i.e. omission errors), but AD participants showed an even distribution of commissions and omissions. Conclusions: Diagnostic criteria for MCI should specify mild functional deficits due to the inefficient and imprecise execution of task steps. Functional deficits characterized by omission of major task segments may indicate a diagnosis of dementia.
Cohabitation with a Sick Cage Mate: Effects on Ascitic Form of Ehrlich Tumor Growth and Macrophage Activity
Authors: Alves Glaucie Jussilane , Vismari Luciana , Palermo-Neto João
Published: March 2008

The present study was designed to evaluate the effects of mice cohabitation with a sick conspecific cage mate on peritoneal macrophage activity and on resistance to Ehrlich tumor growth. Female mice housed in pairs were divided into control and experimental groups. One mouse of each control pair was inoculated with NaCl (0.1 ml/10 g) intraperitoneally and the other, called ‘companion of healthy partner’ (CHP), was kept undisturbed. One animal of each experimental pair of mice was inoculated with 5.0 × 106 Ehrlich tumor cells intraperitoneally and the other, the subject of this study, was called ‘companion of sick partner’ (CSP). Peritoneal macrophages were removed from CSP and CHP mice to analyze resident macrophage activity (experiment 1), macrophage activity after Mycobacterium bovis (experiment 2) or Ehrlich tumor cells (experiment 3) in vivo inoculations. The resistance of CSP and CHP mice to Ehrlich tumor growth was also analyzed (experiment 4). Differences between groups were not found on resident macrophage activity. However, Onco-BCG- and Ehrlich tumor-activated macrophages from CSP mice presented a decreased intensity and percentage of phagocytosis and an increased respiratory burst in the presence of Staphylococcus aureus stimulation in vitro. CSP animals at the same time displayed a decreased resistance to Ehrlich tumor growth. These data were discussed in light of a possible psychological stress effect imposed by the housing condition on mice’s peritoneal macrophage activity and, as a consequence, on their resistance to Ehrlich tumor growth.