bluuebunny/crossref_metadata_2025 huggingface dataset:
Human colonic epithelial cells detect and respond to C5a via apically expressed C5aR through the ERK pathway
Authors: Cao Qi , McIsaac Shayla M. , Stadnyk Andrew W.
Published: April 2012

Intestinal epithelial cells (IECs) exhibit numerous adaptations to maintain barrier function as well as play sentinel roles by expressing receptors for microbial products and antimicrobial peptides. The complement system is another important innate sensing and defense mechanism of the host against bacteria and increasing evidence shows that complement plays a role in colitis. The split component C5a is a potent proinflammatory molecule, and the C5a receptor (C5aR) CD88 has been reported on multiple cell types. Here, we examined the question of whether human colonic cell lines can detect activated complement via C5aR and what signaling pathway is critical in the subsequent responses. T84, HT29, and Caco2 cell lines all possessed mRNA and protein for C5aR and the decoy receptor C5L2. Polarized cells expressed the proteins on the apical cell membrane. C5a binding to the C5aR on human IECs activates the ERK pathway, which proved critical for a subsequent upregulation of IL-8 mRNA, increased permeability of monolayers, and enhanced proliferation of the cells. The fact that human IECs are capable of detecting complement activation in the lumen via this anaphylatoxin receptor highlights the potential for IECs to detect pathogens indirectly through complement activation and be primed to amplify the host response through heightened inflammatory mediator expression to further recruit immune cells.
Exercise training prevents skeletal muscle afferent sensitization in rats with chronic heart failure
Authors: Wang Han-Jun , Li Yu-Long , Zucker Irving H. , Wang Wei
Published: April 2012

An exaggerated exercise pressor reflex (EPR) contributes to exercise intolerance and excessive sympathoexcitation in the chronic heart failure (CHF) state, which is prevented by exercise training (ExT) at an early stage in the development of CHF. We hypothesized that ExT has a beneficial effect on the exaggerated EPR by improving the dysfunction of muscle afferents in CHF. We recorded the discharge of mechanically sensitive ( group III) and metabolically sensitive ( group IV) afferents in response to static contraction, passive stretch, and hindlimb intra-arterial injection of capsaicin in sham+sedentary (Sed), sham+ExT, CHF+Sed, and CHF+ExT rats. Compared with sham+Sed rats, CHF+Sed rats exhibited greater responses of group III afferents to contraction and stretch, whereas the responses of group IV afferents to contraction and capsaicin were blunted. ExT prevented the sensitization of group III responses to contraction or stretch and partially prevented the blunted group IV responses to contraction or capsaicin in CHF rats. Furthermore, we investigated whether purinergic 2X (P2X) and transient receptor potential vanilloid 1 (TRPV1) receptors mediate the altered sensitivity of muscle afferents by ExT in CHF. We found that the upregulated P2X and downregulated TRPV1 receptors in L4/5 dorsal root ganglia of CHF rats were normalized by ExT. Hindlimb intra-arterial infusion of a P2X antagonist attenuated the group III response to contraction or stretch in CHF rats to a greater extent than in sham rats, which was normalized by ExT. These findings suggest that ExT improves the abnormal sensitization of muscle afferents in CHF at least, in part, via restoring the dysfunction of P2X and TRPV1 receptors.
Evidence of a metabolic fatty acid-sensing system in the hypothalamus and Brockmann bodies of rainbow trout: implications in food intake regulation
Authors: Librán-Pérez Marta , Polakof Sergio , López-Patiño Marcos A. , Míguez Jesús M. , Soengas José L.
Published: April 2012

Enhanced lipid levels inhibit food intake in fish but no studies have characterized the possible mechanisms involved. We hypothesize that the presence of fatty acid (FA)-sensing mechanisms could be related to the control of food intake. Accordingly, we evaluated in the hypothalamus, hindbrain, and Brockmann bodies (BB) of rainbow trout changes in parameters related to fatty acid metabolism, transport of FA, nuclear receptors, and transcription factors involved in lipid metabolism, and components of the KATP channel after intraperitoneal administration of different doses of oleic acid (long-chain fatty acid, LCFA) or octanoic acid (medium-chain fatty acid, MCFA). The increase in circulating LCFA or MCFA levels elicited an inhibition in food intake and induced in the hypothalamus a response compatible with fatty acid sensing in which fatty acid metabolism, binding to cluster of differentiation 36 (CD36), and mitochondrial activity are apparently involved, which is similar to that suggested in mammals except for the apparent capacity of rainbow trout to detect changes in MCFA levels. Changes in those hypothalamic pathways can be related to the control of food intake, since food intake was inhibited when FA metabolism was perturbed (using fatty acid synthase or acetyl-CoA carboxylase inhibitors) and changes in mRNA levels of specific neuropeptides such as neuropeptide Y and proopiomelancortin were also noticed. This response seems to be exclusive for the hypothalamus, since the other center controlling food intake (hindbrain) was unaffected by treatments. The results obtained in BB suggest that at least two of the components of a putative fatty acid-sensing system (based on fatty acid metabolism and binding to CD36) could be present. Therefore, the present study provides, for the first time in fish, evidence for a specific role for FA (MCFA and LCFA) as metabolic signals in hypothalamus and BB, where the detection of those FA can be associated with the control of food intake and hormone release.
Changes in glucose tolerance and leptin responsiveness of rats offered a choice of lard, sucrose, and chow
Authors: Harris Ruth B. S. , Apolzan John W.
Published: April 2012

Rats offered chow, lard, and 30% sucrose solution (choice) rapidly become obese. We tested metabolic disturbances in rats offered choice, chow+lard, or chow+30% sucrose solution [chow+liquid sucrose (LS)] and compared them with rats fed a composite 60% kcal fat, 7% sucrose diet [high-fat diet (HFD)], or a 10% kcal fat, 35% sucrose diet [low-fat diet (LFD)]. Choice rats had the highest energy intake, but HFD rats gained the most weight. After 23 days carcass fat was the same for choice, HFD, chow+lard, and chow+LS groups. Glucose clearance was the same for all groups during an intraperitoneal glucose tolerance test (GTT) on day 12, but fasting insulin was increased in choice, LFD fed, and chow+LS rats. By contrast, only choice and chow+LS rats were resistant to an intraperitoneal injection of 2 mg leptin/kg on day 17. In experiment 2 choice rats were insulin insensitive during an intraperitoneal GTT, but this was corrected in an oral GTT due to GLP-1 release. UCP-1 protein was increased in brown fat and inguinal white fat in choice rats, and this was associated with a significant increase in energy expenditure of choice rats during the dark period whether expenditure was expressed on a per animal or a metabolic body size basis. The increase in expenditure obviously was not great enough to prevent development of obesity. Further studies are required to determine the mechanistic basis of the rapid onset of leptin resistance in choice rats and how consumption of sucrose solution drives this process.
Magnetic resonance and confocal imaging of solute penetration into the lens reveals a zone of restricted extracellular space diffusion
Authors: Vaghefi Ehsan , Walker Kerry , Pontre Beau P. , Jacobs Marc D. , Donaldson Paul J.
Published: April 2012

It has been proposed that in the absence of blood supply, the ocular lens operates an internal microcirculation system that delivers nutrients to internalized fiber cells faster and more efficiently than would occur by passive diffusion alone. To visualize the extracellular space solute fluxes potentially generated by this system, bovine lenses were organ cultured in artificial aqueous humor (AAH) for 4 h in the presence or absence of two gadolinium-based contrast agents, ionic Gd3+, or a chelated form of Gd3+, Gd-diethylenetriamine penta-acetic acid (Gd-DTPA; mol mass = 590 Da). Contrast reagent penetration into the lens core was monitored in real time using inversion recovery-spin echo (IR-SE) magnetic resonance imaging (MRI), while steady-state accumulation of [Gd-DTPA]−2 was also determined by calculating T1 values. After incubation, lenses were fixed and cryosectioned, and sections were labeled with the membrane marker wheat germ agglutinin (WGA). Sections were imaged by confocal microscopy using standard and reflectance imaging modalities to visualize the fluorescent WGA label and gadolinium reagents, respectively. Real-time IR-SE MRI showed rapid penetration of Gd3+ into the outer cortex of the lens and a subsequent bloom of signal in the core. These two areas of signal were separated by an area in the inner cortex that limited entry of Gd3+. Similar results were obtained for Gd-DTPA, but the penetration of the larger negatively charged molecule into the core could only be detected by calculating T1 values. The presence of Gd-DTPA in the extracellular space of the outer cortex and core, but its apparent absence from the inner cortex was confirmed using reflectance imaging of equatorial sections. In axial sections, Gd-DTPA was associated with the sutures, suggesting these structures provide a pathway from the surface, across the inner cortex barrier to the lens core. Our studies have revealed inner and outer boundaries of a zone within which a narrowing of the extracellular space restricts solute diffusion and acts to direct fluxes into the lens core via the sutures.
Autophagy protects against necrotic renal epithelial cell-induced death of renal interstitial fibroblasts
Authors: Ponnusamy Murugavel , Liu Na , Sellamuthu Reena , Zhao Ting C. , Mao Haiping , Zhuang Shougang
Published: April 2012

We recently reported that necrotic renal proximal tubular cells (RPTC) can induce the death of renal interstitial fibroblasts. Since autophagy plays either cytoprotective or cytodestructive roles depending on the experimental condition, the present study was carried out to investigate whether necrotic RPTC would induce autophagy of renal interstitial fibroblasts and, if so, whether autophagy would contribute to cell death or exert a protective effect. Exposure of necrotic RPTC supernatant (RPTC-Sup) induced autophagy in renal interstitial fibroblast cells (NRK-49F) in a time- and dose-dependent manner, and its induction was earlier than caspase-3 activation. Inhibition of autophagy with 3-methyladenine (3-MA) or knockdown of Beclin-1, a molecule involved in the initiation of autophagosome formation, with small interference RNA (siRNA) significantly enhanced necrotic RPTC-Sup-induced cell death. Necrotic RPTC-Sup induced phosphorylation of extracellular signal-regulated kinases (ERK1/2), p38, c-Jun NH2-terminal kinases (JNKs), and AKT. Treatment with an ERK1/2 pathway inhibitor, but not with specific inhibitors for p38, JNKs, or AKT pathways, blocked NRK-49F autophagy and cell death upon exposure to necrotic RPTC-Sup. Furthermore, knockdown of MEK1 with siRNA also reduced autophagy along with cell death in NRK-49F exposed to necrotic RPTC-Sup. In contrast, overexpression of MEK1/2 increased RPTC-Sup-induced fibroblast cell death without enhancing autophagy. Collectively, this study demonstrates that necrotic RPTC induce both autophagy and cell death and that autophagy plays a cytoprotective or prosurvival role in renal fibroblasts. Furthermore, necrotic RPTC-induced autophagy and cell death in renal fibroblasts is mediated by the activation of the MEK1-ERK1/2 signaling pathway.
Low plasma carnosinase activity promotes carnosinemia after carnosine ingestion in humans
Authors: Everaert Inge , Taes Youri , De Heer Emile , Baelde Hans , Zutinic Ana , Yard Benito , Sauerhöfer Sibylle , Vanhee Lander , Delanghe Joris , Aldini Giancarlo , Derave Wim
Published: April 2012

A polymorphism in the carnosine dipeptidase-1 gene ( CNDP1), resulting in decreased plasma carnosinase activity, is associated with a reduced risk for diabetic nephropathy. Because carnosine, a natural scavenger/suppressor of ROS, advanced glycation end products, and reactive aldehydes, is readily degraded in blood by the highly active carnosinase enzyme, it has been postulated that low serum carnosinase activity might be advantageous to reduce diabetic complications. The aim of this study was to examine whether low carnosinase activity promotes circulating carnosine levels after carnosine supplementation in humans. Blood and urine were sampled in 25 healthy subjects after acute supplementation with 60 mg/kg body wt carnosine. Precooled EDTA-containing tubes were used for blood withdrawal, and plasma samples were immediately deproteinized and analyzed for carnosine and β-alanine by HPLC. CNDP1 genotype, baseline plasma carnosinase activity, and protein content were assessed. Upon carnosine ingestion, 8 of the 25 subjects (responders) displayed a measurable increase in plasma carnosine up to 1 h after supplementation. Subjects with no measurable increment in plasma carnosine (nonresponders) had ∼2-fold higher plasma carnosinase protein content and ∼1.5-fold higher activity compared with responders. Urinary carnosine recovery was 2.6-fold higher in responders versus nonresponders and was negatively dependent on both the activity and protein content of the plasma carnosinase enzyme. In conclusion, low plasma carnosinase activity promotes the presence of circulating carnosine upon an oral challenge. These data may further clarify the link among CNDP1 genotype, carnosinase, and diabetic nephropathy.
Enhanced intrarenal receptor-mediated prorenin activation in chronic progressive anti-thymocyte serum nephritis rats on high salt intake
Authors: Huang Yanjie , Yamamoto Tatsuo , Misaki Taro , Suzuki Hiroyuki , Togawa Akashi , Ohashi Naro , Fukasawa Hirotaka , Fujigaki Yoshihide , Ichihara Atsuhiro , Nishiyama Akira , Senbonmatsu Takaaki , Ikegaya Naoki , Hishida Akira
Published: April 2012

Despite suppression of the circulating renin-angiotensin system (RAS), high salt intake (HSI) aggravates kidney injury in chronic kidney disease. To elucidate the effect of HSI on intrarenal RAS, we investigated the levels of intrarenal prorenin, renin, (pro)renin receptor (PRR), receptor-mediated prorenin activation, and ANG II in chronic anti-thymocyte serum (ATS) nephritic rats on HSI. Kidney fibrosis grew more severe in the nephritic rats on HSI than normal salt intake. Despite suppression of plasma renin and ANG II, marked increases in tubular prorenin and renin proteins without concomitant rises in renin mRNA, non-proteolytically activated prorenin, and ANG II were noted in the nephritic rats on HSI. Redistribution of PRR from the cytoplasm to the apical membrane, along with elevated non-proteolytically activated prorenin and ANG II, was observed in the collecting ducts and connecting tubules in the nephritic rats on HSI. Olmesartan decreased cortical prorenin, non-proteolytically activated prorenin and ANG II, and apical membranous PRR in the collecting ducts and connecting tubules, and attenuated the renal lesions. Cell surface trafficking of PRR was enhanced by ANG II and was suppressed by olmesartan in Madin-Darby canine kidney cells. These data suggest the involvement of the ANG II-dependent increase in apical membrane PRR in the augmentation of intrarenal binding of prorenin and renin, followed by nonproteolytic activation of prorenin, enhancement of renin catalytic activity, ANG II generation, and progression of kidney fibrosis in the nephritic rat kidneys on HSI. The origin of the increased tubular prorenin and renin remains to be clarified. Further studies measuring the urinary prorenin and renin are needed.
ATP mediates flow-induced NO production in thick ascending limbs
Authors: Cabral Pablo D. , Hong Nancy J. , Garvin Jeffrey L.
Published: April 2012

Mechanical stimulation caused by increasing flow induces nucleotide release from many cells. Luminal flow and extracellular ATP stimulate production of nitric oxide (NO) in thick ascending limbs. However, the factors that mediate flow-induced NO production are unknown. We hypothesized that luminal flow stimulates thick ascending limb NO production via ATP. We measured NO in isolated, perfused rat thick ascending limbs using the fluorescent dye DAF FM. The rate of increase in dye fluorescence reflects NO accumulation. Increasing luminal flow from 0 to 20 nl/min stimulated NO production from 17 ± 16 to 130 ± 37 arbitrary units (AU)/min ( P < 0.02). Increasing flow from 0 to 20 nl/min raised ATP release from 4 ± 1 to 21 ± 6 AU/min ( P < 0.04). Hexokinase (10 U/ml) plus glucose, which consumes ATP, completely prevented the measured increase in ATP. Luminal flow did not increase NO production in the presence of luminal and basolateral hexokinase (10 U/ml). When flow was increased with the ATPase apyrase in both luminal and basolateral solutions (5 U/ml), NO levels did not change significantly. The P2 receptor antagonist suramin (300 μmol/l) reduced flow-induced NO production by 83 ± 25% ( P < 0.03) when added to both and basolateral sides. Luminal hexokinase decreased flow-induced NO production from 205.6 ± 85.6 to 36.6 ± 118.6 AU/min ( P < 0.02). Basolateral hexokinase also reduced flow-induced NO production. The P2X receptor-selective antagonist NF023 (200 μmol/l) prevented flow-induced NO production when added to the basolateral side but not the luminal side. We conclude that ATP mediates flow-induced NO production in the thick ascending limb likely via activation of P2Y receptors in the luminal and P2X receptors in the basolateral membrane.
Thalamic POm projections to the dorsolateral striatum of rats: potential pathway for mediating stimulus–response associations for sensorimotor habits
Authors: Smith Jared B. , Mowery Todd M. , Alloway Kevin D.
Published: April 2012

The dorsolateral part of the striatum (DLS) represents the initial stage for processing sensorimotor information in the basal ganglia. Although the DLS receives much of its input from the primary somatosensory (SI) cortex, peripheral somesthetic stimulation activates the DLS at latencies that are shorter than the response latencies recorded in the SI cortex. To identify the subcortical regions that transmit somesthetic information directly to the DLS, we deposited small quantities of retrograde tracers at DLS sites that displayed consistent time-locked responses to controlled whisker stimulation. The neurons that were retrogradely labeled by these injections were located mainly in the sensorimotor cortex and, to a lesser degree, in the amygdala and thalamus. Quantitative analysis of neuronal labeling in the thalamus indicated that the strongest thalamic input to the whisker-sensitive part of the DLS originates from the medial posterior nucleus (POm), a somesthetic-related region that receives inputs from the spinal trigeminal nucleus. Anterograde tracer injections in POm confirmed that this thalamic region projects to the DLS neuropil. In subsequent experiments, simultaneous recordings from POm and the DLS during whisker stimulation showed that POm consistently responds before the DLS. These results suggest that POm could transmit somesthetic information to the DLS, and this modality-specific thalamostriatal pathway may cooperate with the thalamostriatal projections that originate from the intralaminar nuclei.
β-Adrenergic modulation of spontaneous spatiotemporal activity patterns and synchrony in hyperexcitable hippocampal circuits
Authors: Hazra Anupam , Rosenbaum Robert , Bodmann Bernhard , Cao Siyuan , Josić Krešimir , Žiburkus Jokūbas
Published: April 2012

A description of healthy and pathological brain dynamics requires an understanding of spatiotemporal patterns of neural activity and characteristics of its propagation between interconnected circuits. However, the structure and modulation of the neural activation maps underlying these patterns and their propagation remain elusive. We investigated effects of β-adrenergic receptor (β-AR) stimulation on the spatiotemporal characteristics of emergent activity in rat hippocampal circuits. Synchronized epileptiform-like activity, such as interictal bursts (IBs) and ictal-like events (ILEs), were evoked by 4-aminopyridine (4-AP), and their dynamics were studied using a combination of electrophysiology and fast voltage-sensitive dye imaging. Dynamic characterization of the spontaneous IBs showed that they originated in dentate gyrus/CA3 border and propagated toward CA1. To determine how β-AR modulates spatiotemporal characteristics of the emergent IBs, we used the β-AR agonist isoproterenol (ISO). ISO significantly reduced the spatiotemporal extent and propagation velocity of the IBs and significantly altered network activity in the 1- to 20-Hz range. Dual whole cell recordings of the IBs in CA3/CA1 pyramidal cells and optical analysis of those regions showed that ISO application reduced interpyramidal and interregional synchrony during the IBs. In addition, ISO significantly reduced duration not only of the shorter duration IBs but also the prolonged ILEs in 4-AP. To test whether the decrease in ILE duration was model dependent, we used a different hyperexcitability model, zero magnesium (0 Mg2+). Prolonged ILEs were readily formed in 0 Mg2+, and addition of ISO significantly reduced their durations. Taken together, these novel results provide evidence that β-AR activation dynamically reshapes the spatiotemporal activity patterns in hyperexcitable circuits by altering network rhythmogenesis, propagation velocity, and intercellular/regional synchronization.
Reduction in receptive field size of macaque MT neurons in the presence of visual noise
Authors: Kumano Hironori , Uka Takanori
Published: April 2012

The visual system faces a trade-off between increased spatial integration of disparate local signals and improved spatial resolution to filter out irrelevant noise. Increased spatial integration is beneficial when signals are weak, whereas increased spatial resolution is particularly beneficial when focusing on a small object in a cluttered natural scene. The receptive field (RF) size of visual cortical neurons can be modulated depending on various factors such as sensory context, allowing adaptive integration of sensory signals. In this study, we explored the spatial integration properties of neurons in macaque middle temporal visual area (MT). We hypothesized that spatial resolution would increase when high-contrast noise was presented simultaneously with a visual stimulus, enabling focus on a small object in a cluttered scene. To test this hypothesis, we mapped the RFs of MT neurons of two fixating monkeys in a 5 × 5 grid manner using a small patch of random-dot motion. To examine the effects of noise on RF profile, a dynamic noise (0% coherence dots) of varying diameter was concurrently presented at the RF center. We found that RF size decreased when noise diameter increased. Analyses based on the response normalization model and area summation provided evidence for the potential contribution of spatial summation properties within the RF and surround suppression to the apparent contraction of RF size. Our results suggest that MT neurons integrate smaller regions of motion signals when signals are embedded in noise, an efficient strategy to filter out surrounding noise.
Increased Frontal Lobe Phosphocreatine Levels Observed in Heavy Cocaine Users after Treatment for Cocaine Dependence–An 1H MRS T2 Relaxometry Study
Authors: Ke Y. , Streeter C. , Lowen S. , Nassar L. E. , Parow A. M. , Hennen J. , Yurglun-Todd D. A. , Sarid-Segal O. , Awad L. A. , Rendall M. , Gruber S. A. , Nason A. , Mudrick M. J. , Blank S. R. , Ciraulo D. A. , Renshaw P. F.
Published: April 2012

We have recently reported that relative concentrations of phosphocreatine (PCr) and creatine (Cr) may be estimated from brain 1H MR spectra based upon T2 relaxation times. Emission tomography studies have consistently associated cocaine dependence and abstinence with decreased cerebral metabolism. We hypothesized that increased frontal lobe PCr levels would accompany treatment for cocaine dependence. Twenty‐four cocaine dependent (CD) subjects were studied before and after 8 weeks of cocaine dependence treatment. Nine comparison subjects were studied at the same time points. At baseline, left frontal lobe ratios of PCr/tCr were 0.406±0.081 in CD subjects and 0.411±0.016 in comparison subjects. After treatment, these ratios increased 14.3% (0.464 vs. 0.406;p = 0.006) in CD subjects, remaining unchanged in comparison subjects (2.9%, 0.399 vs. 0.411; p = 0.480). At baseline, PCr levels of non‒responders were 17.8% lower (0.375 vs. 0.442; p = 0.042) than those of responders, defined as 25% decrease in urine cocaine metabolites. After treatment, CD subjects had increased PCr levels: 18.4% (0.444 vs. 0.375; p = 0.035) for non‐responders and 10.4% (0.488 vs. 0.442; p = 0.092) for responders. These results are consistent with decreased cerebral metabolism during treatment, measured as increased PCr. This is the first report using 1H MRS T2 relaxometry to measure a change in human brain energetics.
Solid state NMR study of 1,3imidazolidine‐2‐thione, 1,3‐imidazolidine‐2‐selenone and some of their N‐substituted derivatives
Authors: Wazeer Mohamed I. M. , Isab Anvarhusein A. , El-Rayyes Ali
Published: April 2012

Solid‒state NMR spectra were recorded for 1,3‐imidazolidine‐2‐thione, 1,3‐imidazolidine‐2‐selenone and some of their N‐substituted derivatives. Spinning side‐bands of thione and selenone carbons were analysed to yield chemical shift anisotropies for these carbons. The NMR spectrum of imidazolidine‐2‐thione (Imt) showed some evidence for the presence of thiol tautomer. Molecular computations were carried out for Imt and its N‐methyl derivative to yield relative energies of various tautomers.
Utilization of Agrowaste Polymers in PVC/NBR Alloys: Tensile, Thermal, and Morphological Properties
Authors: Mousa Ahmad , Heinrich Gert , Kretzschmar Bernd , Wagenknecht Udo , Das Amit
Published: April 2012

Poly(vinyl chloride)/nitrile butadiene rubber (PVC/NBR) alloys were melt-mixed using a Brabender Plasticorder at and 50 rpm rotor speed. Alloys obtained by melt mixing from PVC and NBR were formulated with wood-flour- (WF-) based olive residue, a natural byproduct from olive oil extraction industry. WF was progressively increased from 0 to 30 phr. The effects of WF loadings on the tensile properties of the fabricated samples were inspected. The torque rheometry, which is an indirect indication of the melt strength, is reported. The pattern of water uptake for the composites was checked as a function WF loading. The fracture mode and the quality of bonding of the alloy with and without filler are studied using electron scanning microscope (SEM).
Nitrate Removal from Ground Water: A Review
Authors: Archna  , Sharma Surinder K. , Sobti Ranbir Chander
Published: April 2012

Nitrate contamination of ground water resources has increased in Asia, Europe, United States, and various other parts of the world. This trend has raised concern as nitrates cause methemoglobinemia and cancer. Several treatment processes can remove nitrates from water with varying degrees of efficiency, cost, and ease of operation. Available technical data, experience, and economics indicate that biological denitrification is more acceptable for nitrate removal than reverse osmosis and ion exchange. This paper reviews the developments in the field of nitrate removal processes which can be effectively used for denitrifying ground water as well as industrial water.
Synthesis of Novel N1 and N2 Indazole Derivatives
Authors: Bethanamudi Prasanna , Bandari Srinivas , Sankari Kanakaraju , Velidandi Amarnath , Chandramouli G. V. P.
Published: April 2012

The alkylation of 5‐cyano indazoles 2 in the presence of readily available imidizolium salts (ionic liquids) (Bmim)BF4 as phase transfer catalyst were performed to afford the regio isomers N1‐and N2‐(substituted alkyl)‐5‐cyano indazoles. The N1‐alkylated cyano indazoles were converted to the corresponding N1‐(substituted alkyl)‐5‐aminomethyl and 5‐carbaldehydes 5(a-f) and 6(a-f).
Removal of Acid Green 25 from Aqueous Solution by Adsorption
Authors: Parimalam R. , Raj V. , Sivakumar P.
Published: April 2012

The adsorptive removal of Acid Green 25 by Ananas Comosus (L) Activated carbon was investigated in this study. The effects of initial dye concentration, contact time, pH and temperature were studied for the adsorption of Acid Green 25 in batch mode. At 100 mg/L of initial dye concentration the adsorbent removes 182.6 mg/g of dye from solution; it further increases on increasing the temperature. The calculated values of ∆G° indicate that the adsorption process is spontaneous, negative ∆H° indicate that the adsorption process is exothermic and the positive value of ∆S° indicates the increase in randomness. The rate of dye adsorption follows pseudo second order model with an r2 value of 0. 999. Standard adsorption isotherms were used to fit the experimental equilibrium data. The Langmuir, Freundlich, and Tempkin models are appropriate to explain the adsorption phenomenon with good fit.
A Protein Sequence Analysis Hardware Accelerator Based on Divergences
Authors: Eusse Juan Fernando , Moreano Nahri , de Melo Alba Cristina Magalhaes Alves , Jacobi Ricardo Pezzuol
Published: April 2012

The Viterbi algorithm is one of the most used dynamic programming algorithms for protein comparison and identification, based on hidden markov Models (HMMs). Most of the works in the literature focus on the implementation of hardware accelerators that act as a prefilter stage in the comparison process. This stage discards poorly aligned sequences with a low similarity score and forwards sequences with good similarity scores to software, where they are reprocessed to generate the sequence alignment. In order to reduce the software reprocessing time, this work proposes a hardware accelerator for the Viterbi algorithm which includes the concept of divergence, in which the region of interest of the dynamic programming matrices is delimited. We obtained gains of up to 182x when compared to unaccelerated software. The performance measurement methodology adopted in this work takes into account not only the acceleration achieved by the hardware but also the reprocessing software stage required to generate the alignment.
Densities, Viscosities, Refractive Indices and Sound Speeds of Acetophenone with Methylacetate at Different Temperatures
Authors: Saravanakumar K. , Baskaran R. , Kubendran T. R.
Published: April 2012

Densities, viscosities, refractive indices and ultrasonic velocities of the binary mixtures of Acetophenone with Methyl acetate were measured over the entire mole fractions at (303.15, 313.15 and 323.15) K. From these experimental results, excess molar volumes VE, viscosity deviation ∆η, refractive index deviation ∆nD, deviations in isentropic compressibility ∆Ks and excess intermolecular free length ∆Lf are calculated. The viscosity values were fitted to the models of Krishnan‐Laddha and McAllister. The thermo physical properties under study were fit to the Jouyban ‐ Acree model. The excess values were correlated using Redlich‐Kister polynomial equation to obtain their coefficients and standard deviations. It was found that in all cases, the data obtained fitted with the values correlated by the corresponding models very well. The results are interpreted in terms of molecular interactions occurring in the solution.
Severe Maternal Hyperglycemia Exacerbates the Development of Insulin Resistance and Fatty Liver in the Offspring on High Fat Diet
Authors: Song Yong , Li Jibin , Zhao Yong , Zhang Qijuan , Liu Zhiguo , Li Jingna , Chen Xiaoyi , Yang Zhu , Yu Chao , Xiao Xiaoqiu
Published: April 2012

Background. Adverse maternal environments may predispose the offspring to metabolic syndrome in adulthoods, but the underlying mechanism has not been fully understood.Methods. Maternal hyperglycemia was induced by streptozotocin (STZ) injection while control (CON) rats received citrate buffer. Litters were adjusted to eight pups per dam and then weaned to standard diet. Since 13 weeks old, a subset of offspring from STZ and CON dams were switched to high fat diet (HFD) for another 13 weeks. Glucose and insulin tolerance tests (GTT and ITT) and insulin secretion assay were performed; serum levels of lipids and leptin were measured. Hepatic fat accumulation and islet area were evaluated through haematoxylin and eosin staining.Results. STZ offspring exhibited lower survival rate, lower birth weights, and growth inhibition which persisted throughout the study. STZ offspring on HFD showed more severe impairment in GTT and ITT, and more profound hepatic steatosis and more severe hyperlipidemia compared with CON-HFD rats.Conclusions. Offspring from diabetic dams would be prone to exhibit low birth weight and postnatal growth inhibition, but could maintain normal glucose tolerance and insulin sensitivity. HFD accelerates development of insulin resistance in the offspring of diabetic dams mainly via a compensatory response of islets.
Structural Equation Modeling: Theory and Applications in Forest Management
Authors: Lam Tzeng Yih , Maguire Douglas A.
Published: April 2012

Forest ecosystem dynamics are driven by a complex array of simultaneous cause-and-effect relationships. Understanding this complex web requires specialized analytical techniques such as Structural Equation Modeling (SEM). The SEM framework and implementation steps are outlined in this study, and we then demonstrate the technique by application to overstory-understory relationships in mature Douglas-fir forests in the northwestern USA. A SEM model was formulated with (1) a path model representing the effects of successively higher layers of vegetation on late-seral herbs through processes such as light attenuation and (2) a measurement model accounting for measurement errors. The fitted SEM model suggested a direct negative effect of light attenuation on late-seral herbs cover but a direct positive effect of northern aspect. Moreover, many processes have indirect effects mediated through midstory vegetation. SEM is recommended as a forest management tool for designing silvicultural treatments and systems for attaining complex arrays of management objectives.
An Asymmetric Proximal Decomposition Method for Convex Programming with Linearly Coupling Constraints
Authors: Fu Xiaoling , Wang Xiangfeng , Wang Haiyan , Zhai Ying
Published: April 2012

The problems studied are the separable variational inequalities with linearly coupling constraints. Some existing decomposition methods are very problem specific, and the computation load is quite costly. Combining the ideas of proximal point algorithm (PPA) and augmented Lagrangian method (ALM), we propose an asymmetric proximal decomposition method (AsPDM) to solve a wide variety separable problems. By adding an auxiliary quadratic term to the general Lagrangian function, our method can take advantage of the separable feature. We also present an inexact version of AsPDM to reduce the computation load of each iteration. In the computation process, the inexact version only uses the function values. Moreover, the inexact criterion and the step size can be implemented in parallel. The convergence of the proposed method is proved, and numerical experiments are employed to show the advantage of AsPDM.
Microwave Synthesis, Spectral, Thermal and Electrical Properties of Some Metal Complexes Involving 5‐Bromosalicylaldehyde
Authors: Jain Rajendra K. , Mishra A. P. , Mishra D. K. , Gupta S. K.
Published: April 2012

Microwave‐assisted synthesis is a branch of green chemistry. The salient features of microwave approach are shorter reaction times, simple reaction conditions and enhancements in yields. Some new Schiff base complexes of Cr(III), Co(II), Ni(II) and Cu(II) derived from 5‐bromosalicylaldehyde with 4‐nitro‐1,2‐phenylenediamine (H2L1) have been synthesized by conventional as well as microwave methods. These compounds have been characterized by elemental analysis, FT‐IR, FAB‐mass, molar conductance, electronic spectra, ESR, magnetic susceptibility and thermal analysis. The complexes exhibit coordination number 4 or 6. The complexes are coloured and stable in air. Analytical data revealed that all the complexes exhibited 1:1 (metal: ligand) ratio. FAB‐mass and thermal data show degradation pattern of the complexes. The thermal behavior of metal complexes shows that the hydrated complexes loses water molecules of hydration in the first step; followed by decomposition of ligand molecules in the subsequent steps. The solid state electrical conductivity of the metal complexes has also been measured. Solid state electrical conductivity studies reflect semiconducting nature of the complexes.
Post Deposition Annealing Effects on Optical, Electrical and Morphological Studies of ZnTTBPc Thin Films
Authors: Rejitha B. R. , Menon C. S.
Published: April 2012

Phthalocyanines (Pcs) act as efficient absorbants of photons in the visible region, specifically between 600 and 700 nm. It will produce an excited triplet state. In this paper we report the annealing effects of optical, electrical and surface morphological properties of thermal evaporated Zinc‐tetra‐tert‐butyl‐29H, 31H phthalocyanine (ZnTTBPc) thin films. The optical transmittance measurements were done in the visible region (400‐800 nm) and, films were found to be absorbing in nature. From spectral data the absorption coefficient α, dielectric constant ε and the extinction coefficient k were evaluated and, results discussed. Also the optical band gap of the material was estimated. The activation energies were measured. Scanning electron microscopic studies was carried out to determine surface uniformity of films.
Synthesis and Biological Evaluation of Mannich Bases of Isoxazoline Derivatives as Novel Anti‐Microbial Agents
Authors: Sudhir Pawar , Rajashree Chavan , Ashok Bhosale
Published: April 2012

A novel series of compounds were synthesized by condensation reaction of substituted acetophenone (1a-b) with substituted aldehyde (2a-b) in presence of alcoholic sodium hydroxide to get intermediate chalcones (3a-c), which were further treated with hydroxylamine hydrochloride in presence of sodium hydroxide to get isoxazolines derivatives (4a-c). The latter were refluxed with substituted primary amines and formaldehyde for 6‐10 h to afford Mannich bases. The synthesized compounds were characterized on the basis of their spectral (IR, 1HNMR) data and evaluated for the antimicrobial activity by using Zone of Inhibition by cup plate method and Minimum Inhibitory Concentration by broth dilution method.
Versatile Microwave‐Assisted and Lanthanum Chloride Catalysed Synthesis of Polysubstituted Imidazoles Using Urea/Thiourea as Benign Source of Ammonia
Authors: Manafi Mohammad Reza , Manafi Pedram , Kalaee Mohammad Reza
Published: April 2012

Lanthanum chloride was found to be an effective catalyst for the facile and one‐pot synthesis of polysubstituted imidazoles under solvent free condition in excellent yields. This method elucidates urea/thiourea, as an environmentally benign source of ammonia for the synthesis of polysubstituted imidazoles. The work‐up procedure is very simple and the products don’t require further purification.
A Smoothing Inexact Newton Method for Generalized Nonlinear Complementarity Problem
Authors: Li Meixia , Che Haitao
Published: April 2012

Based on the smoothing function of penalized Fischer‐Burmeister NCP‐function, we propose a new smoothing inexact Newton algorithm with non‐monotone line search for solving the generalized nonlinear complementarity problem. We view the smoothing parameter as an independent variable. Under suitable conditions, we show that any accumulation point of the generated sequence is a solution of the generalized nonlinear complementarity problem. We also establish the local superlinear (quadratic) convergence of the proposed algorithm under the BD‐regular assumption. Preliminary numerical experiments indicate the feasibility and efficiency of the proposed algorithm.
MAPK/ERK Signaling in Osteosarcomas, Ewing Sarcomas and Chondrosarcomas: Therapeutic Implications and Future Directions
Authors: Chandhanayingyong Chandhanarat , Kim Yuhree , Staples J. Robert , Hahn Cody , Lee Francis Youngin
Published: April 2012

The introduction of cytotoxic chemotherapeutic drugs in the 1970’s improved the survival rate of patients with bone sarcomas and allowed limb salvage surgeries. However, since the turn of the century, survival data has plateaued for a subset of metastatic, nonresponding osteo, and/or Ewing sarcomas. In addition, most high-grade chondrosarcoma does not respond to current chemotherapy. With an increased understanding of molecular pathways governing oncogenesis, modern targeted therapy regimens may enhance the efficacy of current therapeutic modalities. Mitogen-Activated Protein Kinases (MAPK)/Extracellular-Signal-Regulated Kinases (ERK) are key regulators of oncogenic phenotypes such as proliferation, invasion, angiogenesis, and inflammatory responses; which are the hallmarks of cancer. Consequently, MAPK/ERK inhibitors have emerged as promising therapeutic targets for certain types of cancers, but there have been sparse reports in bone sarcomas. Scattered papers suggest that MAPK targeting inhibits proliferation, local invasiveness, metastasis, and drug resistance in bone sarcomas. A recent clinical trial showed some clinical benefits in patients with unresectable or metastatic osteosarcomas following MAPK/ERK targeting therapy. Despitein vitroproof of therapeutic concept, there are no sufficientin vivoor clinical data available for Ewing sarcomas or chondrosarcomas. Further experimental and clinical trials are awaited in order to bring MAPK targeting into a clinical arena.
A Novel Method for the Synthesis of Dipyrromethanes Under Solvent‐Free Condition
Authors: Shaikh Kabeer A. , Patil Vishal A. , Ahmed Azeem
Published: April 2012

This study describes a successful approach for the synthesis of dipyrromethanes using iodine as a catalyst on grinding. This protocol does not require any solvent and carried out at lowest pyrrole/aldehyde ratio which makes this method economically and environmentally attractive. This protocol affords the products immediately with excellent yield.
Synthesis and Analgesic Studies of Some New 2‐pyrazolines
Authors: Sridhar S. , Rajendraprasad Y.
Published: April 2012

A new series of 2‐pyrazolines (4a‐j) were synthesized by reacting chalcones (3a‐j) with phenyl hydrazine in the presence of pyridine and ethanol. All these compounds were characterized by means of their IR, 1H‐NMR spectral data and microanalyses. When these compounds were evaluated for analgesic activity, some of them were found to possess significant activity, when compared to standard drugs.
Catalytic Behaviors of Expansible Graphite in the Synthesis of Butyl Acetate
Authors: Pang Xiu-Yan
Published: April 2012

The catalysis of expandable graphite EG for esterification has been
studied. EG was prepared with KMnO4 as oxidant and H2SO4 as inserting
reagent. Eexpanded volume，x‐ray diffraction and energy dispersive analysis
for EG were carried, and its catalytic activity was detected in the reaction of
acetic acid with butanol. Influence of mole ratio of butanol and acetic acid,
dosage of EG on ester yield were optimumed single factor experiments. The
suitable esterification condition is: molar ratio of butanol to acetic acid keeps
1.6:1.0, mass of EG keeps 9.0% of the total mass of reactants; reaction keeping
up 1.0 h at the boling point, and esterification rate of 98.2% can be achieved.
The reuse ester yield is 86.6% for first reuse and 61.2% for the second reuse.
Four‐Impulsive Rendezvous Maneuvers for Spacecrafts in Circular Orbits Using Genetic Algorithms
Authors: Santos Denilson Paulo Souza dos , Prado Antônio Fernando Bertachini de Almeida , Colasurdo Guido
Published: April 2012

Spacecraft maneuvers is a very important topic in aerospace engineering activities today. In a more generic way, a spacecraft maneuver has the objective of transferring a spacecraft from one orbit to another, taking into account some restrictions. In the present paper, the problem of rendezvous is considered. In this type of problem, it is necessary to transfer a spacecraft from one orbit to another, but with the extra constraint of meeting another spacecraft when reaching the final orbit. In particular, the present paper aims to analyze rendezvous maneuvers between two coplanar circular orbits, seeking to perform this transfer with lowest possible fuel consumption, assuming that this problem is time‐free and using four burns during the process. The assumption of four burns is used to represent a constraint posed by a real mission. Then, a genetic algorithm is used to solve the problem. After that, a study is made for a maneuver that will make a spacecraft to encounter a planet, in order to make a close approach that will change its energy. Several simulations are presented.
Electrochemical Behaviour of N′‐(p‐toluenesulphonyl)‐3‐methyl‐4‐(4′‐substituted arylhydrazono) pyrazolin‐5‐ones
Authors: Nagaraju V. , Sreenivasulu R. , Ramana P. Venkata
Published: April 2012

The electrochemical behaviour of N′‐(p‐toluenesulphonyl)‐3‐methyl‐4‐(4′‐substituted arylhydrazono) pyrazolin‐5‐ones has been investigated at dme and gc electrodes in buffer solutions of pH 2.0, 4.0, 6.0, 8.0 and 10.0 using dc polarography and cyclic voltammetry and coulometry. The compounds exhibit one well defined wave in the entire pH range of study. The process is irreversible and diffusion controlled. Controlled potential electrolysis indicates the involvement of four electrons in the reduction process. The effect of solvent, cations and anions, temperature and substitutents on the mechanism of reduction has been studied. Based on the results obtained the mechanism of reduction has been suggested.
Three Component Synthesis of Substituted 4H‐[1,3]Dioxin Derivatives Under Solvent‐Free Conditions
Authors: Hosseini-Tabatabaei Mohammad Reza , Akhgar Mohammad Reza , Rafieepour Behnaz , Hassanabadi Alireza , Maghsoodlou Malek Taher , Samadzadeh Marjaneh
Published: April 2012

Reaction between aryl aldehydes, acetylacetone and alkyl isocyanides in solvent‐free conditions provided a simple and efficient one‐pot route for the synthesis of 1‐(2‐alkylamino‐6‐methyl‐4‐aryl‐4H‐[1,3]dioxin‐5‐yl)ethanone derivatives in excellent yields.
Theorems and Application of Local Activity of CNN with Five State Variables and One Port
Authors: Xiong Gang , Dong Xisong , Xie Li , Yang Thomas
Published: April 2012

Coupled nonlinear dynamical systems have been widely studied recently. However, the dynamical properties of these systems are difficult to deal with. The local activity of cellular neural network (CNN) has provided a powerful tool for studying the emergence of complex patterns in a homogeneous lattice, which is composed of coupled cells. In this paper, the analytical criteria for the local activity in reaction-diffusion CNN with five state variables and one port are presented, which consists of four theorems, including a serial of inequalities involving CNN parameters. These theorems can be used for calculating the bifurcation diagram to determine or analyze the emergence of complex dynamic patterns, such as chaos. As a case study, a reaction-diffusion CNN of hepatitis B Virus (HBV) mutation-selection model is analyzed and simulated, the bifurcation diagram is calculated. Using the diagram, numerical simulations of this CNN model provide reasonable explanations of complex mutant phenomena during therapy. Therefore, it is demonstrated that the local activity of CNN provides a practical tool for the complex dynamics study of some coupled nonlinear systems.
Monte‐Carlo Galerkin Approximation of Fractional Stochastic Integro‐Differential Equation
Authors: Badr Abdallah Ali , El-Hoety Hanan Salem
Published: April 2012

A stochastic differential equation, SDE, describes the dynamics of
a stochastic process defined on a space‐time continuum. This paper
reformulates the fractional stochastic integro‐differential equation as
a SDE. Existence and uniqueness of the solution to this equation is
discussed. A numerical method for solving SDEs based on the Monte‐Carlo Galerkin method is presented.