Function Of CB Research Articles

Bio-Based Pyrrole Compounds Containing Sulfur Atoms as Coupling Agents of Carbon Black with Unsaturated Elastomers.

In this work, the hysteresis of elastomer composites suitable for tire compounds was reduced by using CB functionalized with pyrrole compounds containing sulfur-based functional groups reactive with the elastomer chains. CB was functionalized with bio-based pyrrole compounds: 2-(2,5-dimethyl-1H-pyrrol-1-yl)ethane-1-thiol (SHP) and 1,2-bis(2-(2,5-dimethyl-1H-pyr-rol-1-yl)ethyl)disulfide (SSP), bearing an -SH and an -SS- functional group, respectively. SHP and SSP were synthesized via a one-pot two-step synthesis, with yields higher than 70%, starting from biosourced chemicals as follows: 2,5-hexanedione from 2,5-dimethylfuran, cysteine and cysteamine. The functionalization of CB was carried out by mixing the CB with PyC and heating, with quantitative yields ranging from 92 to 97%. Thus, the whole functionalization process was characterized by a high carbon efficiency. The formation of the covalent bond between SHP, SSP and CB, in line with the prior art of such a functionalization technology, was proven by means of extraction and TGA analyses. The reactivity of the sulfur-based functional groups with unsaturated polymer chains was demonstrated by using squalene as the model compound. Poly(styrene-co-butadiene) from solution anionic polymerization and poly(1,4-cis-isoprene) from Hevea Brasiliensis were the elastomers employed for the preparation of the composites, which were crosslinked with a sulfur-based system. Pristine CB was partially replaced with CB/SHP (33%) and CB/SSP (33% and 66%). The PyC resulted in better curing efficiency, an increase in the dynamic rigidity of approximately 20% and a reduction in the hysteresis of approximately 10% at 70 °C, as well as similar/better ultimate tensile properties. The best results were achieved with a 66% replacement of CB with CB/SSP. This new family of reactive carbon blacks paves the way for a new generation of 'green tires', reinforced by a CB reactive with the polymer chains, which provides high mechanical properties and low rolling resistance. Such a reactive CB eliminates the use of silica, and thus the ethanol emission resulting from the condensation of silane is used as a coupling agent. In addition, CB-based tires are characterized by a higher mileage, at a moment in which the reduction in tire wear has become a primary concern.

Clostridium butyricum inhibits the progression of colorectal cancer and alleviates intestinal inflammation via the myeloid differentiation factor 88 (MyD88)-nuclear factor-kappa B (NF-κB) signaling pathway.

BackgroundClostridium butyricum (C. butyricum, CB) is a probiotic to modulate the intestinal disorders and CB supplement has been found to have a great impact on inflammation and cancer treatment. However, the effects and mechanisms of CB on colorectal cancer (CRC) are not clear. We performed this study to investigate the influence of CB on the progression of CRC and the potential mechanisms in vivo and in vitro.MethodsWe established azoxymethane (AOM)/dextran sulfate sodium salt (DSS) model mice (male, 6-week-old C57BL/6J) and divided them into the control (Ctrl) and CB groups at the end of the second DSS cycle. Mice in the CB group received treatment with CB [1×108 colony forming unit (CFU) in 100 µL phosphate buffered saline (PBS)] 3 times a week for 40 days by gavage administration. The apoptotic cells in tumor tissues were assessed by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining. IL-6 and IL-10 were detected using enzyme linked immunosorbent assay (ELISA) assayes. Microbiota was analyzed through 16S rDNA sequencing. The location of CB was detected by the fluorescence in situ hybridization (FISH) assay. The function of CB on the proliferation of cell lines, HT-29 and CT-26, was examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assayes. The expression of myeloid differentiation factor 88 (MyD88) and nuclear factor-kappa B (NF-κB) in cells and tissues was evaluated by real time quantitative PCR (RT-qPCR) and western blot.ResultsMice in the CB group showed a lower incidence and total volume of CRC, more apoptotic cells in the tumor tissue, a lower level of IL-6, and a higher level of IL-10 compared with those in the Ctrl group. CB altered the composition of the gut microbiota and was enriched in the small intestine and tumor tissue. Moreover, CB restrained the proliferation and the expression of MyD88 and NF-κB in CRC cell lines and colon tissue.ConclusionsCB restrained the progression of CRC, improved the inflammation of AOM/DSS mice, altered the composition of their gut microbiota, and regulated the expression of MyD88 and NF-κB. We concluded that CB plays its role in CRC via MyD88 and the NF-κB signaling pathway.

Generalized correlation for predicting the droplet size in a microfluidic flow-focusing device under the effect of surfactant

This paper describes an investigation on the dynamic behavior of droplet formation in a microfluidic flow-focusing device (MFFD) under the effect of surfactant using a phase-field method and the Koterweg stress applied in Navier–Stokes equations. The effects of variously important parameters, such as capillary number (Ca0), water fraction (wf), the viscosity ratio (α), and particularly surfactant concentration (cb), were examined. Consequently, the numerical results match the experimental ones. Additionally, the droplet formation is significantly affected by the surfactant, and the droplet size decreases with increasing cb for the whole range of both wf and Ca0. Based on the extensive study, the phase diagrams with two main modes, namely, dropping and threading, are provided. A mountain shape of the dropping mode was found, and this mode can be extended for higher wf with the presence of surfactant. In particular, new generalized correlations as a function of wf, Ca0, and cb are first proposed for predicting quickly and effectively the droplet size. Furthermore, the droplet formation depends significantly on α. With the presence of surfactant, smaller size of the droplet forms and the threading mode occurs at very high α. The results obtained in this study are very useful for understanding the dynamic behavior of droplet formation in MFFDs, which can be used in potential applications such as biomedical and drug delivery systems.

Investigating the role of conformational dynamics in phospholipase CB function

Phospholipase Cβ (PLCβ) enzymes have a critical role in cardiovascular function by hydrolyzing phosphatidylinositol-4,5-bisphosphate (PIP2) into the second messengers inositol-1,4,5-triphosphate (IP3) and diacylglycerol (DAG), which mobilize intracellular Ca2+ and activate protein kinase C, respectively. PLCβ is autoinhibited under basal conditions but following stimulation of G protein-coupled receptors (GPCRs), it is activated through direct interactions with the heterotrimeric G protein subunits Gαq and Gβγ.

Supramolecular nano drug delivery systems mediated via host-guest chemistry of cucurbit[n]uril (n = 6 and 7)

As a novel family of macrocyclic molecules, cucurbit[n]urils (CB[n]s) have emerged as promising building blocks of supramolecular nano drug delivery systems (SNDDS) in recent years. Direct encapsulation of amphiphilic guests by CB[6] and CB[7] can modulate their amphiphilicity, resulting in formation of supramolecular amphiphiles that self-assemble into supramolecular nanoparticles for drug delivery. Additionally, CB[n]’s host-guest chemistry on the surface of mesoporous nanoparticles makes CB[n] an ideal blocking agent to control drug release from delivery vehicles. These SNDDS possess intrinsic stimuli responsiveness towards external guest or host, which can further incorporate responsiveness to a variety of other stimuli including pH, thermal, redox, photo and enzyme, to realize multiple stimuli-responsive drug release. Moreover, the recent breakthrough in direct functionalization of CB[n]s has provided a feasible method for preparing superior CB[6] and CB[7] derivatives that can be employed to build multifunctional SNDDS with unoccupied macrocycles located on surface, which could be decorated with various functional “tags” through host-guest chemistry. In this review, we summarized the recent progress of CB[6] and CB[7] based SNDDS through formation of supramolecular amphiphiles, supramolecular nanovalves as well as supramolecularly tailorable surface, which we hope to further promote the development of CB[n]s family as building blocks for advanced SNDDS.

Enhancement and mechanism of adsorptive particles on gas-liquid interfacial mass transfer

The aim of this paper is to study the enhancement mechanism of adsorptive particles on gas-liquid interfacial mass transfer. A quantitative model for predicting enhancement factor is proposed based on film model and interfacial non-equilibrium model, in which the enhancement factor depends mainly on the surface fractional coverage θ and the solute bulk concentration Cb, the interfacial concentration of liquid CI is dependent of the mass transfer coefficient kl and Cb, and usually is far from the equilibrium concentration with gas phase at the interface. The surface fractional coverage θ is a function of particle property and operating condition. The present model divided the enhancement into two regimes: particle-transport-controlled regime and surface-adsorption-controlled regime. The increase of gas-liquid mass transfer rate in the presence of adsorptive particles could mainly attributed to the surface adhesion of particles, the enhancement factor is an increasing function of surface fractional coverage θ but a decreasing function of the solute bulk concentration Cb, which well explains the effects of particles concentration and stirring intensity on enhancement factor. The prediction values of present model are at considerably good agreement with experimental data.

Comparative studies on the effect of CB[8] on the charge transfer interaction

Cucurbit[8]uril (CB[8])-stabilized charge transfer pair between 2, 6-dihydroxynaphthalene and methylviologen derivative has been theoretically studied at the PBE0-D3/6-311+G* level. The structure, interaction energy, electron density, and frontier orbital properties of the complex inside CB[8] have been computed and compared with the corresponding properties in gas and water at the same level. Geometric and energetic results show that the guest pair inside CB[8] represents closer packing and stronger binding energy. The VMD program makes the binding strength visible, and the results are consistent with the binding energy results in gas, water, and CB[8]. The results of charge transfer excitation analysis suggest that CB[8] weakens the effect of solvation on the charge transfer excitation to make the complex show a charge transfer character. The calculation results of HOMO and LUMO orbitals suggest that the cavity of the CB[8] is helpful for the intermolecular charge transfer when compared with the case in water and is not involved in this process. This investigation would be useful for our understanding on the function of CB[8] and helpful in designing the supramolecular systems.

Investigation on the hydrolytic mechanism of cucurbit[6]uril in alkaline solution.

The structure of cucurbit[6]uril (CB[6]), as a fascinating supramolecular receptor, is regarded as ‘indestructible’. Herein, we investigated the hydrolysis of CB[6] catalysed by alkali. Our results showed that CB[6] was easily hydrolysed in 30% NaOH at 160°C within 3 h. Separation and purification of hydrolytic products demonstrated the presence of NH3, CO2, HCOONa, glycine and hydantoic acid. Based on the studies of the hydrolysis of substances similar to CB[6] including 4,5-dihydroxyethyleneurea, glycoluril and glycoluril dimer, we proposed that a plausible reaction mechanism involved a Cannizzaro reaction, which is supported by HPLC, mass spectrometry data and previous reports. Further studies are dedicated towards a controlled hydrolysis of CB[6], which will provide a new route for direct functionalization of CB[6].

Tuning the interlaminar shear strength and thermo-mechanical properties of glass fiber composites by incorporation of (3-mercaptopropyl) trimethoxysilane-functionalized carbon black

The incorporation of functionalized nanoscale fillers into traditional glass fiber/unsaturated polyester (GF/UPE) composites provides a more robust mechanical attributes. The current study demonstrates the potential of 3-mercaptopropyl trimethoxysilane (MPTS)-functionalized carbon black (f-CB) for enhancing the thermo-mechanical properties of GF composites. The composites infused with 1, 3 and 5 wt% of pristine and MPTS-functionalized CB were fabricated by hand lay-up and hot press processing. Tensile testing, interlaminar shear strength (ILSS) testing and dynamic mechanical analysis were used to evaluate the performance of nanocomposites. Fourier transform infrared spectroscopy validated the MPTS functionalization of CB. Pristine CB-loaded nanocomposites exhibited marginal improvement in ultimate tensile strength (UTS), ILSS and thermo-mechanical properties. However, with the addition of f-CB, the improvement in all the studied properties was more substantial. The inclusion of 5 wt% f-CB increased the elastic modulus and UTS by 16 and 22%, respectively, whereas the ILSS was enhanced by 36%, in comparison to the neat GF composite. The scanning electron microscope analysis of fractured ILSS samples revealed better fiber-matrix adhesion and compatibility in f-CB-loaded nanocomposites. At the same filler weight percentage, the storage modulus at 25 °C was ~ 19% higher than that of neat composite. The f-CB inclusion resulted in increment of T g by ~ 13 °C over the T g of neat GF/UPE composite (~ 109 °C). These improvements were due to the chemical connection of f-CB to the UPE matrix and GF surface. With such improvements in thermal and mechanical properties, these nanocomposites can replace the conventional GF composites with prominent improvements in performance.

Neurotoxic phospholipase A2 from rattlesnake as a new ligand and new regulator of prokaryotic receptor GLIC (proton-gated ion channel from G. violaceus)

Neurotoxic phospholipases A2 (sPLA2) from snake venoms interact with various protein targets with high specificity and potency. They regulate function of multiple receptors or channels essential to life processes including neuronal or neuromuscular chemoelectric signal transduction. These toxic sPLA2 exhibit high pharmacological potential and determination of PLA2-receptor binding sites represents challenging part in the receptor-channel biochemistry and pharmacology.To investigate the mechanism of interaction of neurotoxic PLA2 with its neuronal receptor at the molecular level, we used as a model crotoxin, a heterodimeric sPLA2 from rattlesnake venom and proton-gated ion channel GLIC, a bacterial homolog of pentameric ligand-gated ion channels. The three-dimensional structures of both partners, crotoxin and GLIC have been solved by X-ray crystallography and production of full-length pentameric GLIC (with ECD and TM domains) is well established.In the present study, for the first time, we demonstrated physical and functional interaction of full-length purified and solubilized GLIC with CB, (PLA2 subunit of crotoxin). We identified GLIC as a new protein target of CB and CB as a new ligand of GLIC, and showed that this non covalent interaction (PLA2-GLIC) involves the extracellular domain of GLIC. We also determined a novel function of CB as an inhibitor of proton-gated ion channel activity. In agreement with conformational changes observed upon formation of the complex, CB appears to be negative allosteric modulator (NAM) of GLIC. Finally, we proposed a possible stoichiometric model for CB – GLIC interaction based on analytical ultracentrifugation.

SIMULATOR KUBIKEL MINIMUM UNTUK INVESTIGASI GANGGUAN SCADA SISTEM DISTRIBUSI TENAGA LISTRIK 20 KV

Wahyu Adi Prasetiyo, Heru Winarno, in this paper explain that with the SCADA system delivery and processing of data from substation equipment consisting of equipment protection, control and measurement becomes faster known by the operator (dispatcher). Measurement and status information indicative of the electric power system are collected in RTU is placed in the substation (GI) which is then sent to the SCADA Master Station.Kinerjasistem dipengaruhiolehpopulasigangguan happened. The more the population of nuisance, then it will significantly reduce the level of reliability of the distribution network which is under the control of the SCADA system. SCADA interference in the distribution of electrical power distribution systems 20 kV affect the level of reliability of the distribution network. Especially if the disturbance of the telecontrol Circuit Breaker. To repair SCADA telecontrol especially the disruption of the necessary investigative trials open close CB, but in emergency situations CB load shedding can not be done with the many considerations. Simulator cubicles with Circuit Breaker Dummy serves to replace the function of the actual CB in order to do the test cubicles control of SCADA without load shedding. By removing the SCADA communication in cubicles and then move it to the CB Dummy testing/investigation disorder can be performed optimally. This tool is equipped with IED Digital Meter Relay Protection and SCADA based so that in addition to the investigation failed control can also be used for investigations and telesignal telemetering disorders. Keywords: scada, investigations, reliability.

Genetic Manipulation of the Endocannabinoid System.

The physiological and pathophysiological functions of the endocannabinoid system have been studied extensively using transgenic and targeted knockout mouse models. The first gene deletions of the cannabinoid CB(1) receptor were described in the late 1990s, soon followed by CB(2) and FAAH mutations in early 2000. These mouse models helped to elucidate the fundamental role of endocannabinoids as retrograde transmitters in the CNS and in the discovery of many unexpected endocannabinoid functions, for example, in the skin, bone and liver. We now have knockout mouse models for almost every receptor and enzyme of the endocannabinoid system. Conditional mutant mice were mostly developed for the CB(1) receptor, which is widely expressed on many different neurons, astrocytes and microglia, as well as on many cells outside the CNS. These mouse strains include "floxed" CB(1) alleles and mice with a conditional re-expression of CB(1). The availability of these mice made it possible to decipher the function of CB(1) in specific neuronal circuits and cell populations or to discriminate between central and peripheral effects. Many of the genetic mouse models were also used in combination with viral expression systems. The purpose of this review is to provide a comprehensive overview of the existing genetic models and to summarize some of the most important discoveries that were made with these animals.

Metabolic monitoring by the carotid body (873.8)

The carotid body is a multimodal sensor. Recently, it has been debated whether the CB also senses glucose and is excited by low glucose. In spite of the conflicting data resulted from different preparations, in vivo data have consistently shown that the CB is likely to be involved in the glucose metabolism. For example, stimulation of the CB by NaCN increased systemic blood glucose (Alvarez-Buylleet al.); carotid sinus denervation eliminated an increase in blood glucose which was induced by chronic intermittent hypoxia (Shin et al.). We found that after 6 hours fasting, blood glucose in young mice (<P14) decreased and hypoxic ventilatory response (HVR) was extremely depressed in spite of low glucose (Shirahata et al.). In addition, leptin deficient mice showed an attenuated HVR (Tankersley et al.). Thus, we have hypothesized that CB is a metabolic monitor and modified by substances related to whole body glucose metabolism. In this study we used adult DBA/2J and C57BL/6J mice. CB function was monitored in vitro by the hypoxic response of the carotid sinus nerve (CSN) which was continually superfused with Krebs solution. Changing glucose at different levels from 10 to 0 mM (replaced by sucrose) did not influence the basal CSN activity nor the CSN response to hypoxia. Insulin did not change the basal and hypoxic CSN activity. Leptin (25-50 ng/mL) significantly increased the basal CSN activity and the response to hypoxia was synergetically augmented. The effect of leptin was partially inhibited by putative trip channel inhibitors (2-APB, SKF). The expression of leptin receptor genes were confirmed in the CB and the petrosal ganglion by RT-PCR analysis. These data suggest that the adult mouse CB does not sense glucose levels directly. Leptin may be a link between metabolic states and CB function, and TRP channels may play a role in leptin-induced excitation of the CB. Grant Funding Source: Supported by HL081345 (MS), HL080105 (VYP), AHA 12POST118200001 (M-KS)

Facile Syntheses of Cucurbit[6]uril-Anchored Polymers and Their Noncovalent Modification

The general strategy for facile synthesis of Cucurbit[6]uril- (CB[6]-) anchored polymers without the functionalization of CB[6] was presented. The acrylamide as a typical monomer was used to synthesize a series of CB[6]-anchored polyacrylamides (CB[6]-PAM) using potassium persulfateas as initiator and oxidant. The CB[6]-PAM samples were characterized by 1H NMR, 13C NMR, HMQC, FTIR, and TGA. It was found that the composition and chain microstructure of CB[6]-PAM polymers could be tunable by changing the content of potassium persulfate, CB[6] and acrylamide. In addition, CB[6]-PAM could be assembled into nanosized vesicles, which were confirmed by TEM, AFM, and SEM measurements. By taking advantage of the exceptional binding affinity of the CB[6], the CB[6]-PAM could be modified with butyl amine hydrochloride. The result makes the CB[6]-anchored polymer potentially useful in many applications. Furthermore, this synthetic approach could be extend to CB[6]-anchored polymers with two different chains. As a typical example, CB[6]-anchored poly(4-vinylbenzylamine hydrochloride salt) and polyacrylamide was synthesized successfully.

Perspectives of Application of Currency Board Arrangement with Special Emphasis on Bosnia and Herzegovina

The relevance of an exchange-rate policy is at top priority list of the monetary authority especially taking into account that the main function of CB or monetary authority is to maintain the stability of the domestic currency. Namely, with the processes of globalization and internationalization of the financial markets the exchange rate of the national currency is more significantly influenced by trends and movements of their most important (global currencies) world currency exchange rates. The aim of this paper is to provide an overview and analysis of development and application of CBA in B&H primary with the aspect of achievement of its functioning as well as its sustainability. Starting from the problem and research objectives following hypothesis is set: Application of CBA in B&H led to the preservation of monetary stability in B&H. For the purposes of assessment of sustainability CBA in B&H we used four types of indicators: Indicator of currency board stability, Indicator of coverage monetary base by foreign reserves, Indicators of coverage monetary base by money supply, as well as Indicator of coverage monetary liabilities by net foreign reserves. The introduction of the CBA in B&H has proved to be very successful. Regulation of the monetary system and restore lost public confidence were significant results of CBA policy.

Brain cannabinoid CB2 receptors modulate cocaine's actions in mice

The presence and function of cannabinoid CB2 receptors in the brain have been subject to debate. We report here that systemic, intranasal or intra-accumbens local administration of JWH133, a selective CB2 receptor agonist, dose-dependently inhibits intravenous cocaine self-administration, cocaine-enhanced locomotion, and cocaine-enhanced accumbens dopamine (DA) in wild-type (WT) and CB1 receptor-knockout (CB1−/−), but not CB2−/−, mice. This inhibition is mimicked by GW405833, another CB2 receptor agonist with a different chemical structure, and is blocked by AM630, a selective CB2 receptor antagonist. Intra-accumbens JWH133 alone dose-dependently decreases, while intra-accumbens AM630 elevates, extracellular DA and locomotion in WT and CB1−/− mice, but not in CB2−/− mice. Intra-accumbens AM630 also blocks the reduction in cocaine self-administration and extracellular DA produced by systemic administration of JWH133. These findings, for the first time, suggest that brain CB2 receptors modulate cocaine’s rewarding and locomotor-stimulating effects, likely by a DA-dependent mechanism.

The cannabinoid type‐1 receptor carboxyl‐terminus, more than just a tail

The cannabinoid type-1 (CB(1)) receptor is a G protein-coupled receptor that binds the main active ingredient of marijuana, Δ(9)-tetrahydrocannabinol, and has been implicated in several disease states, including drug addiction, anxiety, depression, obesity, and chronic pain. In the two decades since the discovery of CB(1), studies at the molecular level have centered on the transmembrane core. This interest has now expanded as we discover that other regions of CB(1), including the CB(1) carboxyl-terminus, have critical structures that are important for CB(1) activity and regulation. Following the recent description of the three dimensional structure of the full-length CB(1) carboxyl-terminal tail [Biopolymers (2009) vol. 91, pp. 565-573], several residues and structural motifs including two α-helices (termed H8 and H9) have been postulated to interact with common G protein-coupled receptor accessory proteins, such as G-proteins and β-arrestins. This discourse will focus on the CB(1) carboxyl-terminus; our current understanding of the structural features of this region, evidence for its interaction with proteins, and the impact of structure on the binding and regulatory function of CB(1) accessory proteins. The involvement of the carboxyl-terminus in the receptor life cycle including activation, desensitization, and internalization will be highlighted.

The isotopic comparative method (ICM) for SIMS quantification of boron in silicon up to 40 at.%

AbstractThis work extends the Isotopic Comparative Method, which has been previously introduced with the aim of correcting matrix effects, to quantify high concentrations of boron in silicon up to 40 at.% by SIMS technique. It requires a specific sample containing two isotopes of the element to quantify: for this study silicon sample with isotope 10B present in constant, sufficiently dilute concentration, quantifiable with the conventional Relative Sensitivity Factor method and the other isotope 11B implanted at very high concentrations. The intensity of 10B, whose concentration ratio with respect to silicon is known and constant, allows to measure the matrix effects induced by the presence of 11B and to deduce the total boron concentration. The variations of the ion yields of boron YB+ and silicon YSi+ as a function of the boron concentration CB are investigated up to 40 at. %. It is found that under Ar+ sputtering there are no matrix effects on Si+ ions, but a doubling of YB+. Under O2+, YB+ and YSi+ increases almost linearly and similarly up to 2.5 times their value in dilute regime. With saturated O2 flooding under Ar+ or O2+, YB+ and YSi+ increase similarly and weakly. These results allow defining an Extended Relative Sensibility Factor method for the quantification of concentrated boron profiles in silicon. It has been successfully implemented in a ∼5 at.% boron layer obtained by Gas Immersion Laser Doping. ICM has been implemented for quantifying high dose boron implantation in silicon (CB up to 40 at.%). Copyright © 2010 John Wiley &amp; Sons, Ltd.

Microstructural behaviors of polyaniline/CB Composites by SAXS

AbstractPolyaniline doped with dodecylbenzene sulfonic acid and conductive carbon black (PAn.DBSA/CB) hybrid materials have been prepared by in situ polymerization. The electrical resistivity of the PAn/CB was measured as a function of CB. The minimum resistivity was noticed for the composites with 25 wt % of CB as compared to other systems. Small angle x‐ray diffraction data was used to characterize the molecular arrangements of these composites. The refinement parameters such as periodicity (L), phase lengths (&lt;Y&gt; and &lt;Z&gt;), phase ratio (&lt;Y&gt;/&lt;Z&gt;), and probability distribution of phases [γZ (crystalline), γY (amorphous)] for PAn, CB, and PAn/CB composites have been measured by SAXS data. It was observed that there is decrease in the crystallinity with increase in CB content in the composites. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Cannabinoid CB 1 receptor activation stimulates neurite outgrowth and inhibits capsaicin-induced Ca 2+ influx in an in vitro model of diabetic neuropathy

Cannabinoid CB 1 receptors mediate, in part, the neuroprotectant properties of endocannabinoids, and altered signalling via the CB 1 receptor may contribute to the pathogenesis of diabetic neuropathy. We investigated CB 1 receptor function in PC12 cells differentiated into a neuronal phenotype with nerve growth factor (NGF, 50 ng/ml) in 5.5 and 50 mM concentrations of glucose. High glucose was associated with impaired NGF-induced neurite outgrowth ( P < 0.01; n = 185–218) and reduced expression of CB 1 receptor mRNA ( P < 0.01; n = 6) on day 6 of culture. Whilst treatment of hyperglycemic cells with HU210 (0.03–3 μM) increased neurite length in a concentration-dependent manner ( P < 0.01; n = 136–218), CB 1 receptor expression was not significantly altered by chronic agonist stimulation ( P = 0.32; n = 6 per group). Application of the CB 1 agonist HU210 (1 μM) inhibited capsaicin-induced calcium transients to a similar degree in cells cultured in high glucose (40%) versus normal (43%) ( P < 0.05; n = 33–50). HU210-mediated rescue of neurite outgrowth and inhibition of calcium influx was blocked by the selective CB 1 antagonist AM251 (1 μM), but not by the selective CB 2 antagonist AM630 (1 μM), confirming the role of CB 1 receptors. High glucose treatment did not significantly elevate endocannabinoid levels. These results suggest that high glucose concentrations are associated with decreased expression, but preserved function of CB 1 receptors in nerve cells.