bluuebunny/crossref_metadata_2025 huggingface dataset:
A MULTIVARIATE PURE-JUMP MODEL WITH MULTI-FACTORIAL DEPENDENCE STRUCTURE
Authors: MARFÈ ROBERTO
Published: June 2012

In this work we propose a new approach to build multivariate pure jump processes. We introduce linear and nonlinear dependence, without restrictions on marginal properties, by imposing a multi-factorial structure separately on both positive and negative jumps. Such a new approach provides higher flexibility in calibrating nonlinear dependence than in other comparable Lévy models in the literature. Using the notion of multivariate subordinator, this modeling approach can be applied to the class of univariate Lévy processes which can be written as the difference of two subordinators. A common example in the financial literature is the variance gamma process, which we extend to the multivariate (multi-factorial) case. The model is tractable and a straightforward multivariate simulation procedure is available. An empirical analysis documents an accurate multivariate fit of stock index returns in terms of both linear and nonlinear dependence. An example of multi-asset option pricing emphasizes the importance of the proposed multivariate approach.
A CLASSIFICATION OF FINITE p-GROUPS WHOSE PROPER SUBGROUPS ARE OF CLASS ≤ 2 (II)
Authors: LI PUJIN
Published: June 2012

A finite group G is said to be a minimal non-[Formula: see text] group if G is not a group of class ≤ n whose proper subgroups are of class ≤ n. In this paper, we give a complete classification of minimal non-[Formula: see text]p-groups G with G3 ≅ Cp × Cp for p > 3.
GOSSIP ON WEIGHTED NETWORKS
Authors: TASGIN MURSEL , BINGOL HALUK O.
Published: June 2012

In this work, we analyze gossip spreading on weighted networks. We try to define a new metric to classify weighted complex networks using our model. The model proposed here is based on the gossip spreading model introduced by Lind et al. on unweighted networks. The new metric is based on gossip spreading activity in the network, which is correlated with both topology and relative edge weights in the network. The model gives more insight about the weight distribution and correlation of topology with edge weights in a network. It also measures how suitable a weighted network is for gossip spreading. We analyze gossip spreading on real weighted networks of human interactions. Six co-occurrence and seven social pattern networks are investigated. Gossip propagation is found to be a good parameter to distinguish co-occurrence and social pattern networks. As a comparison some miscellaneous networks of comparable sizes and computer generated networks based on ER, BA and WS models are also investigated. They are found to be quite different from the human interaction networks.
THEORETICAL STUDY OF THE REGIOSELECTIVITY OF THE ADDITION OF THE TRIPLET OXYGEN ATOM TO UNSYMMETRICAL SUBSTITUTED ALKENES
Authors: MESSAOUDI BOULANOUAR , MEKELLECHE SIDI MOHAMED , MORA-DIEZ NELAINE
Published: June 2012

A theoretical study of the reactivity and regioselectivity of the addition of the triplet oxygen atom O(3P) to a series of unsymmetrical substituted alkenes has been performed at the PMP2/6-311++G (d,p) level of theory. Two reaction pathways, namely, the addition to the substituted carbon atom (α-site) and addition to the non-substituted carbon atom (β-site), have been studied. Our calculations show that the β-addition products are kinetically more favored; whereas the α-addition products are found to be thermodynamically more stable. The regioselectivity (α vs. β) of the addition of the O(3P) to the carbon–carbon double bond is predicted by means of the relative energies of the localized transition states and also by the calculation of spin densities of the3ππ* states of reactants and Fukui indices corresponding to the radical attack to alkenes. Our calculations are in good agreement with experimental outcomes.
THEORETICAL INVESTIGATIONS OF THE CHARGE TRANSFER PROPERTIES IN OLIGOTHIOPHENE DERIVATIVES
Authors: IRFAN AHMAD , AL-SEHEMI ABDULLAH G. , ASIRI ABDULLAH M.
Published: June 2012

The structures of 5,5′-bis(naphth-2-yl)- 2,2′-bithiophene (NaT2), 5,5″-bis(naphth-2-yl)-2,2′:5′,2′-terthiophene (NaT3), 5,5‴-bis(naphth-2-yl)-2,2′:5′,2″:5″,2‴-tetrathiophene (NaT4), 5,5″″-bis(naphth-2-yl)-2,2′:5′,2″:5″,2‴:5‴,2″″-quinquethiophene (NaT5) and 5,5′″″-bis(naphth-2-yl)-2,2′:5′,2″:5″,2‴:5‴,2″″:5″″,2′″″-sexithiophene (NaT6) have been optimized at PBE1PBE/6-31G* level of theory. By increasing the chain length (thiophene units) energy gap decreases. The hole reorganization energy also decreases from NaT2–NaT6 . We have observed that mobility of NaT5 and NaT6 can be enhanced by minimizing the polarization and relaxation. The end-capped naphthyl groups have been rotated from 0°–60° in the case study of NaT2 , it was found that hole reorganization energy increases with the increment in angle. Furthermore the charge transport properties of 5,5′-bis(thionaphth-2-yl)-2,2′-bithiophene (TNT2), 5,5″-bis(thionaphth-2-yl)-2,2′:5′,2″-terthiophene (TNT3), and 5,5‴-bis(thionaphth-2-yl)-2,2′:5′,2″:5″,2‴-quaterthiophene (TNT4) have been investigated at the same level of theory. It has been studied that cis isomers have higher hole reorganization energies as compared to trans ones thus these isomers would diminish the mobility.
CURVILINEAR DYNAMICS OF PROTEIN COMPLEXES
Authors: HENRIKSSON K. O. E. , PESONEN J. , CHACON P.
Published: June 2012

The suitability of a recently developed extension to the polyspherical parametrization of protein complexes has been investigated by molecular dynamic simulations. The extension makes it possible to study the motion of proteins consisting of several chains, which are internally covalently bonded. Tests indicate that time steps of up to at least 10 fs for simulations lasting up to 100 ps are possible, at least for small proteins.
A review of recent advances in 3D ear- and expression-invariant face biometrics
Authors: Islam Syed M. S. , Bennamoun Mohammed , Owens Robyn A. , Davies Rowan
Published: June 2012

Biometric-based human recognition is rapidly gaining popularity due to breaches of traditional security systems and the lowering cost of sensors. The current research trend is to use 3D data and to combine multiple traits to improve accuracy and robustness. This article comprehensively reviews unimodal and multimodal recognition using 3D ear and face data. It covers associated data collection, detection, representation, and matching techniques and focuses on the challenging problem of expression variations. All the approaches are classified according to their methodologies. Through the analysis of the scope and limitations of these techniques, it is concluded that further research should investigate fast and fully automatic ear-face multimodal systems robust to occlusions and deformations.
Identification of a novel intracellular cholesteryl ester hydrolase (carboxylesterase 3) in human macrophages: compensatory increase in its expression after carboxylesterase 1 silencing
Authors: Zhao Bin , Bie Jinghua , Wang Jing , Marqueen Stephanie A. , Ghosh Shobha
Published: June 2012

Cholesteryl ester (CE) hydrolysis is the rate-limiting step in the removal of free cholesterol (FC) from macrophage foam cells, and several enzymes have been identified as intracellular CE hydrolases in human macrophages. We have previously reported the antiatherogenic role of a carboxylesterase [carboxylesterase 1 (CES1)], and the objective of the present study was to determine the contribution of CES1 to total CE hydrolytic activity in human macrophages. Two approaches, namely, immune depletion and short hairpin (sh)RNA-mediated knockdown, were used. Immuneprecipitation by a CES1-specific antibody resulted in a 70–80% decrease in enzyme activity, indicating that CES1 is responsible for >70% of the total CE hydrolytic activity. THP1-shRNA cells were generated by stably transfecting human THP1 cells with four different CES1-specific shRNA vectors. Despite a significant (>90%) reduction in CES1 expression both at the mRNA and protein levels, CES1 knockdown neither decreased intracellular CE hydrolysis nor decreased FC efflux. Examination of the underlying mechanisms for the observed lack of effects of CES1 knockdown revealed a compensatory increase in the expression of a novel CES, CES3, which is only expressed at <30% of the level of CES1 in human macrophages. Transient overexpression of CES3 led to an increase in CE hydrolytic activity, mobilization of intracellular lipid droplets, and a reduction in cellular CE content, establishing CES3 as a bona fide CE hydrolase. This study provides the first evidence of functional compensation whereby increased expression of CES3 restores intracellular CE hydrolytic activity and FC efflux in CES1-deficient cells. Furthermore, these data support the concept that intracellular CE hydrolysis is a multienzyme process.
Contractile activity-induced mitochondrial biogenesis and mTORC1
Authors: Carter Heather N. , Hood David A.
Published: June 2012

In response to exercise training, or chronic contractile activity, mitochondrial content is known to be enriched within skeletal muscle. However, the molecular mechanisms that mediate this adaptation are incompletely defined. Recently, the protein complex, mammalian target of rapamycin complex 1 (mTORC1), has been identified to facilitate the expression of nuclear genes encoding mitochondrial proteins (NUGEMPs) in resting muscle cells via the interaction of the mTORC1 components, mTOR and raptor, the transcription factor Yin Yang 1, and peroxisome proliferator-activated receptor-γ coactivator-1α. It is currently unknown if this mechanism is operative during the increase in mitochondrial content that occurs within skeletal muscle with chronic contractile activity (CCA). Thus we employed a cell culture model of murine skeletal muscle and subjected the myotubes to CCA for 3 h per day for 4 consecutive days in the presence or absence of the mTORC1 inhibitor rapamycin. CCA produced increases in the mitochondrial markers cytochrome oxidase (COX) IV (2.5-fold), Tfam (1.5-fold), and COX activity (1.6-fold). Rapamycin-mediated inhibition of mTORC1 did not suppress these CCA-induced increases in mitochondrial proteins and organelle content. mTORC1 inhibition alone produced a selective upregulation of mitochondrial proteins (COX IV, Tfam), but diminished organelle state 3 respiration. CCA restored this impairment to normal. Our results suggest that mTORC1 activity is not integral for the increase in mitochondrial content elicited by CCA, but is required to maintain mitochondrial function and homeostasis in resting muscle.
Altered astrocyte glutamate transporter regulation of hypothalamic neurosecretory neurons in heart failure rats
Authors: Potapenko Evgeniy S. , Biancardi Vinicia C. , Zhou Yiqiang , Stern Javier E.
Published: June 2012

Neurohumoral activation, which includes augmented plasma levels of the neurohormone vasopressin (VP), is a common finding in heart failure (HF) that contributes to morbidity and mortality in this disease. While an increased activation of magnocellular neurosecretory cells (MNCs) and enhanced glutamate function in HF is well documented, the precise underlying mechanisms remain to be elucidated. Here, we combined electrophysiology and protein measurements to determine whether altered glial glutamate transporter function and/or expression occurs in the hypothalamic supraoptic nucleus (SON) during HF. Patch-clamp recordings obtained from MNCs in brain slices show that pharmacological blockade of astrocyte glutamate transporter 1 (GLT1) function [500 μM dihydrokainate (DHK)], resulted in a persistent N-methyl-d-aspartate receptor (NMDAR)-mediated inward current (tonic INMDA) in sham rats, an effect that was significantly smaller in MNCs from HF rats. In addition, we found a diminished GLT1 protein content in plasma membrane (but not cytosolic) fractions of SON punches in HF rats. Conversely, astrocyte GLAST expression was significantly higher in the SON of HF rats, while nonselective blockade of glutamate transport activity (100 μM TBOA) evoked an enhanced tonic INMDA activation in HF rats. Steady-state activation of NMDARs by extracellular glutamate levels was diminished during HF. Taken together, these results support a shift in the relative expression and function of two major glial glutamate transporters (from GLT1 to GLAST predominance) during HF. This shift may act as a compensatory mechanism to preserve an adequate basal glutamate uptake level in the face of an enhanced glutamatergic afferent activity in HF rats.
Central ventilatory and cardiovascular actions of angiotensin peptides in trout
Authors: Lancien Frédéric , Wong Marty , Arab Ali Al , Mimassi Nagi , Takei Yoshio , Le Mével Jean-Claude
Published: June 2012

In the brains of teleosts, angiotensin II (ANG II), one of the main effector peptides of the renin-angiotensin system, is implicated in various physiological functions notably body fluid and electrolyte homeostasis and cardiovascular regulation, but nothing is known regarding the potential action of ANG II and other angiotensin derivatives on ventilation. Consequently, the goal of the present study was to determine possible ventilatory and cardiovascular effects of intracerebroventricular injection of picomole doses (5–100 pmol) of trout [Asn1]-ANG II, [Asp1]-ANG II, ANG III, ANG IV, and ANG 1–7 into the third ventricle of unanesthetized trout. The central actions of these peptides were also compared with their ventilatory and cardiovascular actions when injected peripherally. Finally, we examined the presence of [Asn1]-ANG II, [Asp1]-ANG II, ANG III, and ANG IV in the brain and plasma using radioimmunoassay coupled with high-performance liquid chromatography. After intracerebroventricular injection, [Asn1]-ANG II and [Asp1]-ANG II two ANG IIs, elevated the total ventilation through a selective stimulatory action on the ventilation amplitude. However, the hyperventilatory effect of [Asn1]-ANG II was threefold higher than the effect of [Asp1]-ANG II at the 50-pmol dose. ANG III, ANG IV, and ANG 1–7 were without effect. In addition, ANG IIs and ANG III increased dorsal aortic blood pressure (PDA) and heart rate (HR). After intra-arterial injections, none of the ANG II peptides affected the ventilation but [Asn1]-ANG II, [Asp1]-ANG II, and ANG III elevated PDA(50 pmol: +80%, +58% and +48%, respectively) without significant decrease in HR. In brain tissue, comparable amounts of [Asn1]-ANG II and [Asp1]-ANG II were detected (ca. 40 fmol/mg brain tissue), but ANG III was not detected, and the amount of ANG IV was about eightfold lower than the content of the ANG IIs. In plasma, ANG IIs were also the major angiotensins (ca. 110 fmol/ml plasma), while significant but lower amounts of ANG III and ANG IV were present in plasma. In conclusion, our study suggests that the two ANG II isoforms produced within the brain may act as a neurotransmitter and/or neuromodulator to regulate the cardioventilatory functions in trout. In the periphery, two ANG IIs and their COOH-terminal peptides may act as a circulating hormone preferentially involved in cardiovascular regulations.
The startle response during whiplash: a protective or harmful response?
Authors: Mang Daniel W. H. , Siegmund Gunter P. , Inglis J. Timothy , Blouin Jean-Sébastien
Published: June 2012

Whiplash injuries are common following rear-end collisions. During such collisions, initially relaxed occupants exhibit brisk, stereotypical muscle responses consisting of postural and startle responses that may contribute to the injury. Using prestimulus inhibition, we sought to determine if the startle response elicited during a rear-end collision contributes to head stabilization or represents a potentially harmful overreaction of the body. Three experiments were performed. In the first two experiments, two groups of 14 subjects were exposed to loud tones (124 dB) preceded by prestimulus tones at either four interstimulus intervals (100–1,000 ms) or five prestimulus intensities (80–124 dB). On the basis of the results of the first two experiments, 20 subjects were exposed to a simulated rear-end collision (peak sled acceleration = 2 g; speed change = 0.75 m/s) preceded by one of the following: no prestimulus tone, a weak tone (85 dB), or a loud tone (105 dB). The prestimulus tones were presented 250 ms before sled acceleration onset. The loud prestimulus tone decreased the amplitude of the sternocleidomastoid (16%) and cervical paraspinal (29%) muscles, and key peak kinematics: head retraction (17%), horizontal head acceleration (23%), and head angular acceleration in extension (23%). No changes in muscle amplitude or kinematics occurred for the weak prestimulus. The reduced muscle and kinematic responses observed with loud tones suggest that the startle response represents an overreaction that increases the kinematics in a way that potentially increases the forces and strains in the neck tissues. We propose that minimizing this overreaction during a car collision may decrease the risk of whiplash injuries.
Minimum acceleration with constraints of center of mass: a unified model for arm movements and object manipulation
Authors: Leib Raz , Karniel Amir
Published: June 2012

Daily interaction with the environment consists of moving with or without objects. Increasing interest in both types of movements drove the creation of computational models to describe reaching movements and, later, to describe a simplified version of object manipulation. The previously suggested models for object manipulation rely on the same optimization criteria as models for reaching movements, yet there is no single model accounting for both tasks that does not require reminimization of the criterion for each environment. We suggest a unified model for both cases: minimum acceleration with constraints for the center of mass (MACM). For point-to-point reaching movement, the model predicts the typical rectilinear path and bell-shaped speed profile as previous criteria. We have derived the predicted trajectories for the case of manipulating a mass-on-spring and show that the predicted trajectories match the observations of a few independent previous experimental studies of human arm movement during a mass-on-spring manipulation. Moreover, the previously reported “unusual” trajectories are also well accounted for by the proposed MACM. We have tested the predictions of the MACM model in 3 experiments with 12 subjects, where we demonstrated that the MACM model is equal or better (Wilcoxon sign-rank test, P < 0.001) in accounting for the data than three other previously proposed models in the conditions tested. Altogether, the MACM model is currently the only model accounting for reaching movements with or without external degrees of freedom. Moreover, it provides predictions about the intermittent nature of the neural control of movements and about the dominant control variable.
Altered dendritic complexity affects firing properties of cortical layer 2/3 pyramidal neurons in mice lacking the 5-HT3A receptor
Authors: van der Velden Luuk , van Hooft Johannes A. , Chameau Pascal
Published: June 2012

We have previously shown that the serotonergic input on Cajal-Retzius cells, mediated by 5-HT3 receptors, plays an important role in the early postnatal maturation of the apical dendritic trees of layer 2/3 pyramidal neurons. We reported that knockout mice lacking the 5-HT3A receptor showed exuberant apical dendrites of these cortical pyramidal neurons. Because model studies have shown the role of dendritic morphology on neuronal firing pattern, we used the 5-HT3A knockout mouse to explore the impact of dendritic hypercomplexity on the electrophysiological properties of this specific class of neurons. Our experimental results show that hypercomplexity of the apical dendritic tuft of layer 2/3 pyramidal neurons affects neuronal excitability by reducing the amount of spike frequency adaptation. This difference in firing pattern, related to a higher dendritic complexity, was accompanied by an altered development of the afterhyperpolarization slope with successive action potentials. Our abstract and realistic neuronal models, which allowed manipulation of the dendritic complexity, showed similar effects on neuronal excitability and confirmed the impact of apical dendritic complexity. Alterations of dendritic complexity, as observed in several pathological conditions such as neurodegenerative diseases or neurodevelopmental disorders, may thus not only affect the input to layer 2/3 pyramidal neurons but also shape their firing pattern and consequently alter the information processing in the cortex.
A quantitative analysis of information about past and present stimuli encoded by spikes of A1 neurons
Authors: Klampfl Stefan , David Stephen V. , Yin Pingbo , Shamma Shihab A. , Maass Wolfgang
Published: June 2012

To process the rich temporal structure of their acoustic environment, organisms have to integrate information over time into an appropriate neural response. Previous studies have addressed the modulation of responses of auditory neurons to a current sound in dependence of the immediate stimulation history, but a quantitative analysis of this important computational process has been missing. In this study, we analyzed temporal integration of information in the spike output of 122 single neurons in primary auditory cortex (A1) of four awake ferrets in response to random tone sequences. We quantified the information contained in the responses about both current and preceding sounds in two ways: by estimating directly the mutual information between stimulus and response, and by training linear classifiers to decode information about the stimulus from the neural response. We found that 1) many neurons conveyed a significant amount of information not only about the current tone but also simultaneously about the previous tone, 2) the neural response to tone sequences was a nonlinear combination of responses to the tones in isolation, and 3) nevertheless, much of the information about current and previous tones could be extracted by linear decoders. Furthermore, our analysis of these experimental data shows that methods from information theory and the application of standard machine learning methods for extracting specific information yield quite similar results.
Presynaptic NMDA receptor-mediated modulation of excitatory neurotransmission in the mouse dorsal motor nucleus of the vagus
Authors: Bach Eva C. , Smith Bret N.
Published: June 2012

Activity of neurons in the dorsal motor nucleus of the vagus nerve (DMV) is closely regulated by synaptic input, and regulation of that input by glutamate receptors on presynaptic terminals has been proposed. Presynaptic N-methyl-d-aspartic acid (NMDA) receptors have been identified in a number of brain regions and act to modulate neurotransmitter release, but functional presynaptic NMDA receptors have not been adequately studied in the DMV. This study identified the presence and physiological function of presynaptic NMDA receptors on synaptic input to DMV neurons. Whole-cell patch-clamp recordings from DMV neurons in acute slices from mice revealed prevalent miniature excitatory postsynaptic currents, which were significantly increased in frequency, but not amplitude, by application of NMDA. Antagonism of NMDA receptors with dl-2-amino-5-phosphonopentanoic acid (100 μM) resulted in a decrease in miniature excitatory postsynaptic current frequency and an increase in the paired pulse ratio of responses following afferent stimulation. No consistent effects of presynaptic NMDA receptor modulation were observed on GABAergic inputs. These results suggest that presynaptic NMDA receptors are present in the dorsal vagal complex and function to facilitate the release of glutamate, preferentially onto DMV neurons tonically, with little effect on GABA release. This type of presynaptic modulation represents a potentially novel form of glutamate regulation in the DMV, which may function to regulate glutamate-induced activity of central parasympathetic circuits.
Time-dependent effect of acute hypoxia on corticospinal excitability in healthy humans
Authors: Rupp T. , Jubeau M. , Wuyam B. , Perrey S. , Levy P. , Millet G. Y. , Verges S.
Published: June 2012

Contradictory results regarding the effect of hypoxia on cortex excitability have been reported in healthy subjects, possibly depending on hypoxia exposure duration. We evaluated the effects of 1- and 3-h hypoxia on motor corticospinal excitability, intracortical inhibition, and cortical voluntary activation (VA) using transcranial magnetic stimulation (TMS). TMS to the quadriceps cortex area and femoral nerve electrical stimulations were performed in 14 healthy subjects. Motor-evoked potentials (MEPs at 50–100% maximal voluntary contraction; MVC), recruitment curves (MEPs at 30–100% maximal stimulator power output at 50% MVC), cortical silent periods (CSP), and VA were measured in normoxia and after 1 ( n = 12) or 3 ( n = 10) h of hypoxia (FiO2 = 0.12). One-hour hypoxia did not modify any parameters of corticospinal excitability but reduced slightly VA, probably due to the repetition of contractions 1 h apart (96 ± 4% vs. 94 ± 4%; P = 0.03). Conversely, 3-h hypoxia significantly increased 1) MEPs of the quadriceps muscles at all force levels (+26 ± 14%, +24 ± 12%, and +27 ± 17% at 50, 75, and 100% MVC, respectively; P = 0.01) and stimulator power outputs (e.g., +21 ± 14% at 70% maximal power), and 2) CSP at all force levels (+20 ± 18%, +18 ± 19%, and +14 ± 22% at 50, 75, and 100% MVC, respectively; P = 0.02) and stimulator power outputs (e.g., +9 ± 8% at 70% maximal power), but did not modify VA (98 ± 1% vs. 97 ± 3%; P = 0.42). These data demonstrate a time-dependent hypoxia-induced increase in motor corticospinal excitability and intracortical inhibition, without changes in VA. The impact of these cortical changes on physical or psychomotor performances needs to be elucidated to better understand the cerebral effects of hypoxemia.
Fuzzy Stability of ann-Dimensional Quadratic and Additive Functional Equation
Authors: Lee Yang Hi , Jung Soon-Mo
Published: June 2012

We will investigate a fuzzy version of stability for the functional equation2f(∑i=1nxi)+∑1≤i,j≤n,i≠jf(xi-xj)=(n+1)∑i=1nf(xi)+(n-1)∑i=1nf(-xi)in the sense of Mirmostafaee and Moslehian.
Prevention of the Musculoskeletal Complications of Hemophilia
Authors: Rodriguez-Merchan E. C.
Published: June 2012

Hemophilia is an inherited disorder of clotting factor deficiencies resulting in musculoskeletal bleeding, including hemarthroses, leading to musculoskeletal complications. The articular problems of hemophiliac patients begin in infancy. These include: recurrent hemarthroses, chronic synovitis, flexion deformities, hypertrophy of the growth epiphyses, damage to the articular cartilage, and hemophilic arthropathy. The most commonly affected joints are the ankle, the knee, and the elbow. Hematologic prophylactic treatment from ages 2 to 18 years could avoid the development of hemophilic arthropathy if the concentration of the patient's deficient factor is prevented from falling below 1% of normal. Hemarthroses can be prevented by the administration of clotting factor concentrates (prophylaxis). However, high costs and the need for venous access devices in younger children continue to complicate recommendations for universal prophylaxis. Prevention of joint arthropathy needs to focus on prevention of hemarthroses through prophylaxis, identifying early joint disease through the optimal use of cost-effective imaging modalities and the validation of serological markers of joint arthropathy. Screening for effects on bone health and optimal management of pain to improve quality of life are, likewise, important issues. Major hemarthrosis and chronic hemophilic synovitis should be treated aggressively to prevent hemophilic arthropathy.
Bioabsorbable Pins for Treatment of Osteochondral Fractures of the Knee after Acute Patella Dislocation in Children and Young Adolescents
Authors: Gkiokas A. , Morassi L. G. , Kohl S. , Zampakides C. , Megremis P. , Evangelopoulos D. S.
Published: June 2012

A retrospective study was performed on the use of bioabsorbable pins in the fixation of osteochondral fractures (OCFs) after traumatic patellar dislocation in children. Eighteen children (13 females, 5 males) aged 11 to 15 years (mean age 13.1 years) with osteochondral fracture (OCF) of the knee joint were treated at the authors’ institution. Followup ranged from 22 months to 5 years. Diagnosis was verified by X-ray and magnetic resonance imaging (MRI) of the knee and patella. In seven patients the osteochondral fragment was detached from the patella and in 11 it was detached from the lateral femoral condyle. All patients were subjected to open reduction and fixation of the lesion with bioabsorbable pins. Postoperatively, the knee was immobilized in a cast and all patients were mobilized applying a standardized protocol. Bone consolidation was successful in 17 of the 18 patients. Bioabsorbable pins reliably fix OCF in children and adolescents, demonstrating a high incidence of consolidation of the detached osteochondral fragment in short- and middle-term followup without requiring further operative procedures.
Sleep Apnea and Cognitive Function in Heart Failure
Authors: Knecht Krysten M. , Alosco Michael L. , Spitznagel Mary Beth , Cohen Ronald , Raz Naftali , Sweet Lawrence , Colbert Lisa H. , Josephson Richard , Hughes Joel , Rosneck Jim , Gunstad John
Published: June 2012

Background. Prior research indicates that heart failure (HF) patients exhibit significant cognitive deficits on neuropsychological testing. Sleep apnea is associated with both HF and reduced cognitive function, but the combined impact of these conditions on cognitive function is unknown. Methods. In the current study, 172 older adults with a dual diagnosis of HF and sleep apnea or HF alone completed a battery of cognitive tests measuring attention, executive functioning, and memory. Results. Relative to patients with HF alone, persons with both HF and sleep apnea performed worse on measures of attention after adjusting for demographic and medical variables. Conclusions. The current findings suggest that HF patients with comorbid sleep apnea may be at greater risk for cognitive impairment relative to HF patient without such history. Further work is needed to clarify mechanisms for these findings and to determine whether the interactive effects on cognitive function lead to poorer patient outcomes.
Comparative Study of Vibrational Spectra of Two Bioactive Natural Products Lupeol and Lupenone Using MM/QM Method
Authors: Dwivedi Apoorva , Pandey Anoop Kumar , Raj Kanwal , Misra Neeraj
Published: June 2012

This work deals with the theoretical study on the molecular structure and vibrational spectra of two well-known natural products: lupeol and lupenone. The spectra were interpreted with the aid of normal mode analysis following full-structure optimization carried out with the hybrid two-level ONIOM (B3LYP/6-31G: PM3) method. A detailed interpretation of the infrared spectra of Lupeol and Lupenone is also reported in the present work. The similarities and differences between the vibrational spectra of the two molecules studied have been highlighted. The scaled theoretical wave numbers are in perfect agreement with the experimental values. The thermodynamic calculations related to the title compounds were also performed at B3LYP/6-31G: PM3 level of theory. Quantum chemical calculations have been carried out to understand the dynamical behavior of the bioactive molecules Lupeol and Lupenone.
Cardiac Myxoma Presenting as Dyspnea after Cesarean Delivery
Authors: Wyman Allison , Hurd William , Lappen Justin
Published: June 2012

Introduction.Dyspnea during pregnancy and in the immediate postpartum or postoperative period is a relatively common symptom that can be an early sign of a life threatening condition. The differential diagnosis is broad and can represent a wide variety of underlying etiologies. Cardiac tumors are one of the rarest causes of dyspnea in a reproductive age women during the postpartum period.Case Presentation.42-years old G7P1051presented with acute dyspnea postoperatively after an elected uncomplicated repeat cesarean section and tubal ligation. The patient was diagnosed with a large left atrial cardiac myxoma and required urgent cardiothoracic surgery.Conclusion.The following case illustrates how a standard response to a common postpartum symptom, dyspnea, can divert and distract from less common exam findings. A careful, stepwise evaluation of symptoms and related findings will usually determine the underlying cause so that appropriate and timely treatment can be initiated.
Conservatively Treated Incidental Aneurysm of the Distal Left Main Coronary Artery: Detection by Coronary Angiography and Noninvasive Followup Using Coronary Computed Tomography Angiography
Authors: Hofmann Nina P. , Abdel-Aty Hassan , Siebert Stefan , Katus Hugo A. , Korosoglou Grigorios
Published: June 2012

Coronary artery aneurysms are relatively rare and commonly associated with significant coronary artery disease (CAD), inflammatory diseases (Kawasaki syndrome, infection), or iatrogenic complications. Herein, we report an unusual case of an incidental coronary aneurysm of the left main artery in a patient without specific clinical symptoms of myocardial ischemia or systemic inflammation and without angiographically significant CAD. Angiographic images are provided, acquired during cardiac catheterization, as well as coronary computed tomography angiography (CCTA) images obtained at 1 year of followup.
Spectrofluorometric Analysis of New-Generation Antidepressant Drugs in Pharmaceutical Formulations, Human Urine, and Plasma Samples
Authors: Das Ruchita S. , Agrawal Y. K.
Published: June 2012

Spectrofluorometric analysis for the quantification of new-generation antidepressant drugs belong to the class of selective serotonin reuptake inhibitors and selective norepinephrine reuptake inhibitors is described. Five different drugs, sertraline, paroxetine, citalopram, venlafaxine, and fluoxetine, were analysed for spectrofluorometric detection in pharmaceutical formulations and urine and plasma samples. The calibration curves were found linear between fluorescence intensity and drugs concentration in the range of 5–500 ng/L with coefficients of determination above 0.9985 for all the analytes. The method recoveries were higher than 85% in all the three matrices. The intra- and interday variation coefficients were observed less than 8% and 13%, respectively. The limits of detection (LOD) and limit of quantification (LOQ) were found in the range of 0.016–0.084 ng/L and 0.090–0.285 ng/L, respectively. Additionally, the results were compared statistically for each analyte in all the three matrices and were found equivalent, which signifies the absence of matrix effect. Thus, the method will be applied successfully to the determination of the cited drugs in pure or dosage forms as well as in biological fluids with good accuracy and precision.
Synthesis of Neutral / Hydrosol and Its Application as Antireflective Self-Cleaning Thin Film
Authors: Huang Chiahung , Bai Hsunling , Huang Yaoling , Liu Shuling , Yen Shaoi , Tseng Yaohsuan
Published: June 2012

A neutral SiO2/TiO2composite hydrosol was prepared by a coprecipitation-peptization method using titanium tetrachloride and silicon dioxide hydrosol as precursors. It is not only an antireflective self-cleaning coating material but also an environmental-benign material. Even heated at 700°C for 5 minutes in the tempering process, the as-prepared SiO2/TiO2thin film still demonstrated antireflection and photocatalytic self-cleaning effect. The SiO2/TiO2thin film increased near 2% of transmittance; however, the TiO2thin film decreased 5% of transmittance at least. In addition to antireflection, the SiO2/TiO2thin film decomposed the surface coated oleic acid under ultraviolet light and showed superhydrophilicity under dark for two days. The SiO2/TiO2thin film also showed good photocatalytic degradation of methylene blue. With these antireflection, persistent superhydrophilicity, and photocatalytic self-cleaning effects, this prepared neutral SiO2/TiO2hydrosol would be a good coating material for tempered glass and other building materials.
Ewingella Americana: An Emerging True Pathogen
Authors: Hassan Syed , Amer Syed , Mittal Chetan , Sharma Rishi
Published: June 2012

Infections caused byEwingella americanahave been rarely reported in the literature. Most of the cases that have been reported were among the immunocompromised patients. We report a case ofE. americanacausing osteomyelitis and septic arthritis of the shoulder joint in a previous intravenous drug abuser. The causative pathogen was identified by synovial fluid analysis and culture.
Effects of Somatic Mutations in the C-Terminus of Insulin-Like Growth Factor 1 Receptor on Activity and Signaling
Authors: Craddock Barbara P. , Miller W. Todd
Published: June 2012

The insulin-like growth factor I receptor (IGF1R) is overexpressed in several forms of human cancer, and it has emerged as an important target for anticancer drug design. Cancer genome sequencing efforts have recently identified three somatic mutations in IGF1R: A1374V, a deletion of S1278 in the C-terminal tail region of the receptor, and M1255I in the C-terminal lobe of the kinase catalytic domain. The possible effects of these mutations on IGF1R activity and biological function have not previously been tested. Here, we tested the effects of the mutations on thein vitrobiochemical activity of IGF1R and on major IGF1R signaling pathways in mammalian cells. While the mutations do not affect the intrinsic tyrosine kinase activity of the receptor, we demonstrate that the basal (unstimulated) levels of MAP kinase and Akt activation are increased in the mutants (relative to wild-type IGF1R). We hypothesize that the enhanced signaling potential of these mutants is due to changes in protein-protein interactions between the IGF1R C-terminus and cellular substrates or modulators.
Spectrophotometric Determination of Thioridazine Hydrochloride in Tablets and Biological Fluids by Ion-Pair and Oxidation Reactions
Authors: El-Didamony Akram , Hafeez Sameh
Published: June 2012

Two simple, sensitive and selective spectrophotometric methods have been described for the determination of the psychoactive drug, thioridazine HCl in tablets and in biological fluids. The first method is based on the oxidation of thioridazine HCl with measured excess of KMnO4under acidic conditions followed by the determination of unreacted oxidant using indigo carmine and methyl orange. The second method is based on the formation of ion-pair complexes with the acidic sulphophthalein dyes such as bromocresol green and bromocresol purple at pH 1.8 of KCl-HCl buffer. The formed complexes were extracted into methylene chloride and their absorbance was measured at 412 nm. Optimizations of the different experimental conditions are described for both methods. The proposed methods were successfully applied for determination of the drug in tablets and biological fluids with good accuracy and precision. Statistical comparison of the results with those obtained by an official method showed good agreement and indicated no significant difference in accuracy and precision.
A Comparison of Inflammatory and Oxidative Stress Markers in Adipose Tissue from Weight-Matched Obese Male and Female Mice
Authors: Nickelson Karen J. , Stromsdorfer Kelly L. , Pickering R. Taylor , Liu Tzu-Wen , Ortinau Laura C. , Keating Aileen F. , Perfield James W.
Published: June 2012

Expansion of intra-abdominal adipose tissue and the accompanying inflammatory response has been put forward as a unifying link between obesity and the development of chronic diseases. However, an apparent sexual dimorphism exists between obesity and chronic disease risk due to differences in the distribution and abundance of adipose tissue. A range of experimental protocols have been employed to demonstrate the role of estrogen in regulating health benefits; however, most studies are confounded by significant differences in body weight and adiposity. Therefore, the purpose of this study was to compare weight-matched obese male and female mice to determine if the sex-dependent health benefits remain when body weight is similar. The development of obesity in female mice receiving a high-fat diet was delayed; however, subsequent comparisons of weight-matched obese mice revealed greater adiposity in obese female mice. Despite excess adiposity and enlarged adipocyte size, obese females remained more glucose tolerant than weight-matched male mice, and this benefit was associated with increased expression of adiponectin and reductions in immune cell infiltration and oxidative stress in adipose tissue. Therefore, the protective benefits of estrogen persist in the obese state and appear to improve the metabolic phenotype of adipose tissue and the individual.
Preparation and Characterization of Folate Targeting Magnetic Nanomedicine Loaded with Cisplatin
Authors: Xie Minqiang , Xu Yiming , Liu Jie , Zhang Tao , Zhang Hongzheng
Published: June 2012

We used Aldehyde sodium alginate (ASA) as modifier to improve surfactivity and stability of magnetic nanoparticles, and folate acid (FA) as targeting molecule. Fe3O4 nanoparticles were prepared by chemical coprecipitation method. FA was activated and coupled with diaminopolyethylene glycol (NH2‐PEG‐NH2). ASA was combined with Fe3O4 nanoparticles, and FA‐PEG was connected with ASA by Schiff’s base formation. Then Cl- in cisplatin was replaced by hydroxyl group in ASA, and FA‐ and ASA‐modified cisplatin‐loaded magnetic nanomedicine (CDDP‐FA‐ASA‐MNPs) was prepared. This nanomedicine was characterized by transmission electron microscopy, dynamic lighterring scattering, phase analysis light scattering and vibrating sample magnetometer. The uptake of magnetic nanomedicine by nasopharyngeal and laryngeal carcinoma cells with folate receptor positive or negative expression were observed by Prussian blue iron stain and transmission electron microscopy. We found that CDDP‐FA‐ASA‐MNPs have good water‐solubility and stability. Mean diameter of Fe3O4 core was 8.17 ± 0.24 nm, hydrodynamic diameters was 110.90 ± 1.70 nm, and zeta potential was −26.45 ± 1.26 mV. Maximum saturation magnetization was 22.20 emu/g. CDDP encapsulation efficiency was 49.05 ± 1.58% (mg/mg), and drug loading property was 14.31 ± 0.49% (mg/mg). In vitro, CDDP‐FA‐ASA‐MNPs were selectively taken up by HNE‐1 cells and Hep‐2 cells, which express folate receptor positively.
Chlorophyll Fluorescence Spectra as an Indicator of X-Ray+EMS-Induced Phytotoxicity in Safflower
Authors: Pandey Jitendra Kumar , Srivastava Preeti , Yadav Ram Singh , Gopal Ram
Published: June 2012

The present investigation deals with the study of in vivo laser-induced chlorophyll florescence spectra (LICF) of safflower leaves (Carthamus tinctoriusL.) for X-rays+EMS-treated plants. Seeds were treated with different doses of X-ray+EMS (5, 8, 12, 25, and 30 Kr+0.5% EMS) and were grown in the green house. The effects of the concerned treatment on chlorophyll (Chl) contents and Chl fluorescence were investigated after 7 days of germination. Results obtained revealed that the values of Chl contents, intensity of Chl fluorescence spectra, and fluorescence intensity ratio (FIR) F685/F730 are directly correlated with the treatment doses monitored. The treatment sets of 8, 12, and 25 Kr + 0.5% EMS doses showed an increase in FIR and thereby a decrease in the Chl contents. However, the lowest treatment dose of 5 Kr + 0.5% showed a decrease in FIR and thereby an increase in chlorophyll contents. Safflower seeds treated with 30 Kr + 0.5% EMS were proved to be lethal as they showed no germination. Thus, our study demonstrates early detection of chlorophyll damage caused by various physical and chemical mutagens through the application of LICF spectra.
Influence of Intercalation‐Exfoliation‐Reduction Technique towards the Physico‐Chemical of VPO Catalysts
Authors: Wong Y. C. , Taufiq-Yap Y. H.
Published: June 2012

Four VPO catalysts were synthesized through intercalation and exfoliation in various alcohols and subsequent reduction of the exfoliated VOPO4 sheets with various alcohols to produce VOHPO4·0.5H2O. The resulting VOHPO4·0.5H2O that undergoes the intercalation‐exfoliation‐reduction (IER) process will be further activated into VPO catalysts, and addition of 1 mole % Bi(NO3)3·5H2O in the first stage of this experiment has also being investigated. The synthesized materials were characterized by X‐ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and temperature‐programmed reduction (TPR) in H2. Catalytic evaluation of the IER‐treated and Bi‐doped VPO catalysts was also studied on microreactor. The VPO catalyst produced through IER using 2‐butanol and ethanol with addition of Bi, IERC(2Bu‐Et)RBi1, gave the highest MA selectivity due to reactive O2− species released from the additional crystalline V5+ phase formed by doping 1% bismuth as promoter (O2−‐V5+ pair) at relative lower temperature. Nevertheless, the VPO catalyst produced through IER using isobutanol, IERC(isoBu), gave the highest activity due to high amount of reactive O− species released from V4+ phase (O−‐V4+ pair) whereby the IERC(isoBu) catalyst synthesized consists of high percentage of V4+ (93 %).
Prediction of Gas Chromatography‐Mass Spectrometry Retention Times of Pesticide Residues by Chemometrics Methods
Authors: Konoz Elaheh , Sarrafi Amir H. M. , Feizbakhsh Alireza , Dashtbozorgi Zahra
Published: June 2012

A quantitative structure‐retention relationships (QSRRs) method is employed to predict the retention time of 300 pesticide residues in animal tissues separated by gas chromatography‐mass spectroscopy (GC‐MS). Firstly, a six‐parameter QSRR model was developed by means of multiple linear regression. The six molecular descriptors that were considered to account for the effect of molecular structure on the retention time are number of nitrogen, Solvation connectivity index‐chi 1, Balaban Y index, Moran autocorrelation‐lag 2/weighted by atomic Sanderson electronegativity, total absolute charge, and radial distribution function‐6.0/unweighted. A 6‐7‐1 back propagation artificial neural network (ANN) was used to improve the accuracy of the constructed model. The standard error values of ANN model for training, test, and validation sets are 1.559, 1.517, and 1.249, respectively, which are less than those obtained reveals by multiple linear regressions model (2.402, 1.858, and 2.036, resp.). Results obtained the reliability and good predictability of nonlinear QSRR model to predict the retention time of pesticides.
Breakthrough Curve Analysis for Column Dynamics Sorption of Mn(II) Ions from Wastewater by Using Mangostana garcinia Peel‐Based Granular‐Activated Carbon
Authors: Chowdhury Z. Z. , Zain S. M. , Rashid A. K. , Rafique R. F. , Khalid K.
Published: June 2012

The potential of granular‐activated carbon (GAC) derived from agrowaste of Mangostene (Mangostana garcinia) fruit peel was investigated in batch and fixed bed system as a replacement of current expensive methods for treating wastewater contaminated by manganese, Mn(II) cations. Batch equilibrium data was analyzed by Langmuir, Freundlich, and Temkin isotherm models at different temperatures. The effect of inlet metal ion concentration (50 mg/L, 70 mg/L, and 100 mg/L), feed flow rate (1 mL/min and 3 mL/min), and activated carbon bed height (4.5 cm and 3 cm) on the breakthrough characteristics of the fixed bed sorption system were determined. The adsorption data were fitted with well‐established column models, namely, Thomas, Yoon‐Nelson, and Adams‐Bohart. The results were best‐fitted with Thomas and Yoon‐Nelson models rather than Adams‐Bohart model for all conditions. The column had been regenerated and reused consecutively for five cycles. The results demonstrated that the prepared activated carbon was suitable for removal of Mn(II) ions from wastewater using batch as well as fixed bed sorption system.