Evidence for non-independent gating of P2X<Subscript>2</Subscript> receptors expressed in <Emphasis Type="Italic">Xenopus</Emphasis>oocytes

Background  

P2X₂ receptor is an ATP-activated ion channel which is widely expressed in the nervous system, and mediates synaptic transmission.     

Sodium channel Na<Subscript>v</Subscript>1.7 immunoreactivity in painful human dental pulp and burning mouth syndrome

Background  

Voltage gated sodium channels Na_v1.7 are involved in nociceptor nerve action potentials and are known to affect pain sensitivity in clinical genetic disorders.     

Detection of human and rodent 5-HT3B receptor subunits by anti-peptide polyclonal antibodies

Background  

The 5-HT₃ receptor is a member of a neurotransmitter-gated ion channel family which includes nicotinic acetylcholine, GABA_A, and glycine receptors. While antibodies specific for the 5-HT_3A receptor subunit are plentiful, and have revealed a wealth of structural and functional information, few antisera exist for the detection of 5-HT_3B receptor subunits. Here we describe the generation and characterisation of a rabbit polyclonal antiserum that specifically recognises 5-HT_3B receptor subunits     

Detrimental effects of tropisetron on permanent ischemic stroke in the rat

Background  

Recent in vitro evidence indicates that blockade of 5-hydroxytryptamine (5-HT) receptor 3 (5-HT₃) is able to confer protection in different models of neuronal injury. The purpose of the present study was to investigate the effect of tropisetron, a 5-HT₃ receptor antagonist, on infarct size and neurological score in a model of ischemic stroke induced by permanent middle cerebral artery occlusion (pMCAO) in the rat.     

Serotonin 5-HT2A and 5-HT6 receptors in the prefrontal cortex of Alzheimer and normal aging patients

Background  

It has been hypothesized that alterations of the serotonergic system contribute to neuropsychiatric symptoms in Alzheimer disease (AD). Cellular expressions of the two serotonergic receptors 5-HT_2A and 5-HT₆ have therefore been determined by immunohistochemistry in the prefrontal cortex of patients with AD (n=6) and normal age-matched controls (n = 7).     

Bouncing behaviors of suspension liquid drops on a superhydrophobic surface

Abstract  

This paper reveals three patterns of bouncing behaviors of suspension drops containing calcium carbonate (CaCO₃) powder on a superhydrophobic surface with the aid of a high-speed camera. In transmission electron microscopy (TEM) observation, the particles of CaCO₃ are shaped like sticks whose equivalent diameters are about 700 nm. Unlike a pure water drop, dense suspension drops cannot be pinched off at the bounce on the superhydrophobic surface due to a high effective viscosity, whereas the equilibrium contact angle appears to be almost identical in all kinds of droplets.     

Sol–gel glass-ceramics comprising rare-earth doped SnO<Subscript>2</Subscript> and LaF<Subscript>3</Subscript> nanocrystals: an efficient simultaneous UV and IR to visible converter

Abstract  

We report a novel class of nanostructured glass-ceramics comprising two co-existing rare-earth doped nanocrystalline phases, SnO₂ semiconductor nanocrystal (quantum dot), and LaF₃, presenting sizes at around 4.6 and 9.8 nm, respectively, embedded into a silica glass matrix for an efficient simultaneous UV and IR to visible photon conversion. On one hand, the wide and strong UV absorption by SnO₂ quantum dot and subsequent efficient energy transfer to Eu³⁺ and, on the other hand, the also very efficient IR to visible up-conversion with the pair Yb³⁺–Er³⁺ partitioned into low phonon LaF₃ nanocrystalline environment, yield to visible emissions with application in improving the spectral response of photovoltaic solar cells.     

Microwave-assisted rapid synthesis of Ag nanoparticles/graphene nanosheet composites and their application for hydrogen peroxide detection

Abstract  

Ag nanoparticles/graphene nanosheet (AgNPs/GN) composites have been rapidly prepared by a one-pot microwave-assisted reduction method, carried out by microwave irradiation of a N,N-dimethylformamide (DMF) solution of graphene oxide (GO) and AgNO₃. Several analytical techniques including UV–vis spectroscopy, FT-IR spectroscopy, Raman spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM) have been used to characterize the resulting AgNPs/GN composites. It suggests that such composites exhibit good catalytic activity toward reduction of hydrogen peroxide (H₂O₂), leading to a H₂O₂ sensor with a fast amperometric response time of less than 2 s. The linear detection range is estimated to be from 0.1 to 100 mM (r = 0.999), and the detection limit is estimated to be 0.5 μM at a signal-to-noise ratio of 3.     

Covariates of corticotropin-releasing hormone (CRH) concentrations in cerebrospinal fluid (CSF) from healthy humans

Background  

Define covariates of cerebrospinal corticotropin-releasing hormone (CRH) levels in normal humans. CRH_CSF was measured in 9 normal subjects as part of an intensive study of physiological responses stressors in chronic pain and fatigue states. CRH_CSF was first correlated with demographic, vital sign, HPA axis, validated questionnaire domains, baseline and maximal responses to pain, exercise and other stressors. Significant factors were used for linear regression modeling.     

Prenatal cocaine exposure alters alpha2 receptor expression in adolescent rats

Background  

Prenatal cocaine exposure produces attentional deficits which to persist through early childhood. Given the role of norepinephrine (NE) in attentional processes, we examined the forebrain NE systems from prenatal cocaine exposed rats. Cocaine was administered during pregnancy via the clinically relevant intravenous route of administration. Specifically, we measured α₂-adrenergic receptor (α₂-AR) density in adolescent (35-days-old) rats, using [³H]RX821002 (5 nM).     

Preparation and characterization of nickel hydroxide microspheres assembled by nanoribbons

Abstract  

This article describes a facile green strategy for preparing the Ni(OH)₂ microsphere assembled by nanoribbons by the template of the squama inner coat of onion at mild condition. The method is simple and effective. The results of SEM show the products are Ni(OH)₂ microspheres with diameters in the range of 500–2,500 nm. The results of TEM show the microsphere is assembly by nanoribbons, with thickness in the range of 30–50 nm. The products were characterized by powder X-ray diffraction, IR, and thermogravimetric analysis. A possible formation mechanism was also proposed.     

Mesoporous silica-coated superparamagnetic particles prepared by pseudomorphic transformation and their application in purification of plasmid DNA

Abstract  

Mesoporous silica-coated superparamagnetic particles were prepared via pseudomorphic transformation of pre-made amorphous silica-coated Fe₃O₄–polymer composite particles using n-cetyltrimethylammonium bromide (CTAB) and 1,3,5-trimethyl benzene (MES) as template. The mesoporous particles presented almost the same size, shape, and magnetic property as the original amorphous particles but an ordered mesoporous shell with wormhole-like pore structure. The pore size of the shells increased from 2.4 to 3.1 and 4.2 nm as the molar ratio of MES/CTAB increased from 0 to 1.0 and 1.5. DNA extraction experiments showed the mesoporous particles were qualified for purification of plasmid DNA from bacterial lysate.     

Chloride equilibrium potential in salamander cones

Background  

GABAergic inhibition and effects of intracellular chloride ions on calcium channel activity have been proposed to regulate neurotransmission from photoreceptors. To assess the impact of these and other chloride-dependent mechanisms on release from cones, the chloride equilibrium potential (E_Cl) was determined in red-sensitive, large single cones from the tiger salamander retinal slice.     

The excitation cascade of <Emphasis Type="Italic">Limulus</Emphasis> ventral photoreceptors: guanylate cyclase as the link between InsP<Subscript>3</Subscript>-mediated Ca<Superscript>2+</Superscript>release and the opening of cGMP-gated channels

Background  

Early stages in the excitation cascade of Limulus photoreceptors are mediated by activation of G_q by rhodopsin, generation of inositol-1,4,5-trisphosphate by phospholipase-C and the release of Ca²⁺. At the end of the cascade, cGMP-gated channels open and generate the depolarizing receptor potential. A major unresolved issue is the intermediate process by which Ca²⁺ elevation leads to channel opening.     

Plasticity of histamine H<Subscript>3</Subscript>receptor expression and binding in the vestibular nuclei after labyrinthectomy in rat

Background  

In rat, deafferentation of one labyrinth (unilateral labyrinthectomy) results in a characteristic syndrome of ocular and motor postural disorders (e.g., barrel rotation, circling behavior, and spontaneous nystagmus). Behavioral recovery (e.g., diminished symptoms), encompassing 1 week after unilateral labyrinthectomy, has been termed vestibular compensation. Evidence suggesting that the histamine H₃ receptor plays a key role in vestibular compensation comes from studies indicating that betahistine, a histamine-like drug that acts as both a partial histamine H₁ receptor agonist and an H₃ receptor antagonist, can accelerate the process of vestibular compensation.     

Transient change in GABAA receptor subunit mRNA expression in Lurcher cerebellar nuclei during Purkinje cell degeneration

Background  

Lurcher mice suffer from a complete Purkinje cell (PC) loss in the first four postnatal weeks. Parallel to this degeneration, GABAergic synapses in the deep cerebellar nuclei (DCN), the major recipient of the inhibitory PC projection, increase synaptic conductance. Here, we further investigated this phenomenon, using real-time RT-PCR to assess GABA_A receptor subunit gene expression during PC degeneration.     

Effects of prostaglandin E<Subscript>2</Subscript> on the electrical properties of thermally classified neurons in the ventromedial preoptic area of the rat hypothalamus

Background  

Physiological and morphological evidence suggests that activation of the ventromedial preoptic area of the hypothalamus (VMPO) is an essential component of an intravenous LPS-dependent fever. In response to the endogenous pyrogen prostaglandin E₂ (PGE₂), the majority of temperature insensitive neurons in the VMPO show an increase in firing rate, while warm sensitive neurons are inhibited. We have hypothesized that these PGE₂ dependent effects on firing rate are due to changes in the inherent electrical properties of VMPO neurons, which are regulated by the activity of specific ionic currents.     

Immunocytochemical evidence for co-expression of Type III IP3 receptor with signaling components of bitter taste transduction

Background  

Taste receptor cells are responsible for transducing chemical stimuli into electrical signals that lead to the sense of taste. An important second messenger in taste transduction is IP₃, which is involved in both bitter and sweet transduction pathways. Several components of the bitter transduction pathway have been identified, including the T2R/TRB taste receptors, phospholipase C β2, and the G protein subunits α-gustducin, β3, and γ13. However, the identity of the IP₃ receptor subtype in this pathway is not known. In the present study we used immunocytochemistry on rodent taste tissue to identify the IP₃ receptors expressed in taste cells and to examine taste bud expression patterns for IP₃R3.     

Flow measurement around a cycloidal propeller

Abstract  

An experimental investigation was conducted to study the flow around a cycloidal propeller. Flow fields were obtained using a particle image velocimetry system whose data acquisition was synchronized with the propeller’s angular position. The chord-based Reynolds number was Re _c = u _r c/υ = 1.4 × 10⁴, where u _r is the rotational velocity of the propeller and c is the chord length of the airfoil. Flow characteristics such as mean velocity, vorticity and the RMS value of velocity fluctuation were derived from the measurements. The results demonstrated the presence of a downwash around the propeller during the generation of lift. Detailed observations around each airfoil visualized distinct vortex shedding and reattaching flow at certain phase angles of the propeller.     

Cellular and subcellular localization of Marlin-1 in the brain

Background  

Marlin-1 is a microtubule binding protein that associates specifically with the GABA_B1 subunit in neurons and with members of the Janus kinase family in lymphoid cells. In addition, it binds the molecular motor kinesin-I and nucleic acids, preferentially single stranded RNA. Marlin-1 is expressed mainly in the central nervous system but little is known regarding its cellular and subcellular distribution in the brain.