To study the effect of agonist on the TRH (thyrotrophin-releasing hormone) receptor protein, an epitope-tagged receptor was stably expressed in HEK-293 cells (human embryonic kidney 293 cells) and receptor...Full Text Available
Selective estrogen receptor modulators (SERMs) represent a class with a growing number of compounds that act as either estrogen receptoragonists or antagonists in a tissue-specific manner. This article...Full Text Available
BACKGROUND: H2-histamine receptors mediate a wide range of physiological functions extending from stimulation of gastric acid secretion to induction of human promyelocyte differentiation. We have previously...Full Text Available
BackgroundThe aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that mediates the toxicity and biological activity of dioxins and related chemicals. The...Full Text Available
Serotonin is one of the neurotransmitters found in the brain and mediates brain functions. It is very well known that serotonin related brain abnormalities are exerted mainly via serotonin receptors in a similar manner to other neurotransmitters found in the brain. Recently, it has also been found that serotonin is involved in Alzheimer's disease either directly or indirectly by its actions on serotonergic neurons. To understand and treat the diseases caused by abnormalities in the serotonergic system in the brain, it is certain that its mechanism of function has to be well investigated. So far several 5-HT receptors and receptor subtypes have been well characterized. Moreover, serotonin agonists and antagonists acting on specific receptors are chemically synthesized and are now available for the prevention or treatment of serotonergic related diseases. In recent years, a great ...
Introduction: Development of agonist positron emission tomography (PET) radioligands for the 5-HT neurotransmitter system is an important target to enable the understanding of human 5-HT function in vivo. ["1"1C]CUMI-101, proposed as the first 5-HT_1_A receptoragonist PET ligand, has been reported to behave as a potent 5-HT_1_A agonist in a cellular system stably expressing human recombinant 5-HT_1_A receptors. In this study, we investigate the agonist properties of CUMI-101 in rat brain tissue. Methods: ["3"5S]-GTP#gamma#S binding studies were used to determine receptor function in HEK (human embryonic kidney) 293 cells transfected with human recombinant 5-HT_1_A receptors and in rat cortex and rat hippocampal tissue, following administration of CUMI-101 and standard 5-HT1A antagonists (5-HT, 5-CT and 8-OH-DPAT). ...
BackgroundPostoperative delirium is a topic of great importance in the geriatric surgical specialty. Although antipsychotic drugs are the medications most frequently used to treat...Full Text Available
The effects of paeoniflorin (PF), a compound isolated from Paeony radix, on neurological impairment and histologically measured infarction volume...Full Text Available
Objective:To investigate the combined effect of both pioglitazone and methotrexate on disease activity of rheumatoid arthritis in a biphasic study; experimental and clinical.Methods:Experimentally:...Full Text Available
BackgroundCancer stem cells (CSCs) have increased resistance to cancer chemotherapy. They can be enriched as drug-surviving CSCs (D-CSCs) by growth with chemotherapeutic drugs, and/or...Full Text Available
BackgroundTo evaluate whether P2X receptors are involved in responses to noxious pulp stimulation, the P2X3 and P2X2/3 receptoragonist α,β-methyleneATP...Full Text Available
The receptor occupancy-biological effect relationship for muscarinic receptors in guinea pig ileal smooth muscle has been studied by comparison of radioligand binding and contractile response. Muscarinic receptors in homogenates of ileal smooth muscle were labeled with (/sub 3/H)-1-Quinuclidinyl benzilate. Treatment with propylbenzilylcholine mustard (PrBCM), to inactivate irreversibly muscarinic receptors, caused a large dose dependent rightward shift of the dose-response curve to three agonistic furtrethonium derivatives with a concomitant decrease in maximal response. Using those data, the fraction of receptors remaining unoccupied (q-values) and true affinity constants (-log K/sub A/-values) were calculated. Exposure to 20 or 60 nM PrBCM for 15 minutes resulted in a 39% and a 61% reduction in specific (/sup 3/H)-1-Quinuclidinyl benzilate binding sites ...
Several examples of agonist-directed trafficking of receptor signalling at 5-HT2A and 5-HT2C receptors have been reported that involve independent downstream transduction pathways. We now report the functional selectivity of a series of chemically diverse agonists at human (h)5-HT2A, h5-HT2B and h5-HT2C-VSV by examining two related responses, the upstream activation of Gq/11 proteins in comparison with its associated cascade of calcium mobilisation. At the h5-HT2A receptor, d-lysergic acid diethylamide (LSD) and the antiparkinsonian agents lisuride, bromocriptine and pergolide exhibit a higher potency for Gq/11 activation than calcium release in contrast with all the other tested ligands such as 5-HT, mCPP and BW723C86, that show an opposite preference of signalling pathway. Comparable observations are made at h5-HT2B and h5-HT2C-VSV receptors, suggesting a ...
Background2-Methylthioadenosine 5'-triphosphate (2-MeSATP), formerly regarded as a specific P2Y (metabotropic) purinergic receptoragonist, stimulates Ca2+ influx and...Full Text Available
σ-Receptor (σR) antagonists have been reported to block certain effects of psychostimulant drugs. The present study examined the effects of σR ligands in rats trained to self-administer...Full Text Available
The substantia nigra pars reticulata (SNR) controls seizures in a sex-specific manner. At postnatal day 15 (P15), SNR infusion of GABAAreceptoragonist muscimol have proconvulsant...Full Text Available
The present paper further characterizes the cholinergic properties of acetylselenonium choline (ASeCh, (CH3)2Se+CH2CH2OCOCH3). The data demonstrate that ASeCh possesses muscarinic receptoragonist properties as evidenced by vasodepressor and smooth muscle contractile activities which are enhanced by physostigmine and antagonized by atropine. ASeCh also possessed nicotinic agonist activity on frog rectus abdominis tissue which was potentiated by physostigmine, and blocked by d-tubocurarine. The relative potencies of ASeCh ranged from approximately 1% to approximately 6% of the potency of acetylcholine in the three types of preparations examined. PMID:1435078
Results in this study are consistent with those of Murdock and his colleagues who clearly demonstrated that clonidine, an agonist of octopaminergic receptors in some insects, significantly increases sucrose feeding. Their studies, however, did not examine the effect of clonidine on protein feeding. Injection of a 20mg/ml/fly dose of clonidine significantly reduces protein feeding in both sexes of Phormia regina, instead of stimulating feeding as is observed with carbohydrate feeding. The manner in which the flies are fed prior to starvation and the method of testing influences the amounts of diet consumed. It is proposed that the biogenic amines influence the state of hunger (i.e., protein versus carbohydrates) while other chemicals and neural mechanisms (i.e., such as sulfakinins and stre...
Proton pump inhibitors are highly successful in treating gastroesophageal reflux disease, but a significant proportion of patients have persistent symptoms from weakly or nonacidic reflux. Transient lower esophageal sphincter relaxation (TLESR) represents the dominant mechanism of gastroesophageal reflux and has therefore become the most intensely investigated therapeutic target. The triggering of TLESR involve the vagal pathways and the ?-aminobutyric type B (GABA(B)) and metabotropic glutamate type 5 (mGluR5) receptors. Baclofen is a GABA(B) receptoragonist that is effective in inhibiting TLESR and reducing the number of reflux episodes, but is associated with significant central nervous system (CNS) side effects. The newer GABA(B) agonists, such as AZD9343 and AZD3355, and mGluR5 antag...
Aim: There has been a great demand for developments of the radioligands to visualize the N-methyl-D-aspartate (NMDA) receptors by PET/SPECT. We have recently synthesized two C-11 labeled antagonists for the glycine-binding site on NMDA receptors. The aim of this work is to examine for their in vitro and in vivo binding characteristics, and to evaluate their potentials as PET radioligands for the NMDA receptors. Materials and methods: Two C-11 labeled 4-hydroxy-2-quinolones (1 and 2) were synthesized by conventional methylation of the corresponding phenols with ["1"1C]methyl iodide. In vitro and ex vivo quantitative autoradiographs with imaging plate, as well as animal PET, were employed in order to evaluate their in vitro and in vivo binding to the NMDA receptors. Results: The compound 1 showed the specific binding to rat brain slices with higher localization in the hippocampus and cerebral cortex than ...
Metabotropic glutamate receptor 2/3 (mGluR2/3) agonists were shown previously to nonselectively decrease both cocaine- and food-maintained responding in rats. mGluR2 positive allosteric modulators (PAMs)...Full Text Available
AimsRosiglitazone and fenofibrate, specific agonists of the peroxisome proliferator activated receptors-γ (PPARγ) and -α (PPARα),...Full Text Available
ABSTRACT: Metabolomic analysis will provide the next large set of clues to further our understanding of human health and disease. A recent study has elucidated the significant differences in the metabolomes of adipocytes, serum and an adipocyte cell line after activation of two nuclear receptors, peroxisome proliferator activated receptor ?/? (PPAR?/?) and PPAR?. These findings hold great promise for explaining fundamental differences in the mechanisms of PPAR agonists and for identifying targets for the treatment of diabetes.See related research article: http://genomebiology.com/2011/12/8/R75. PMID:21861850
In rat adipocyte membranes, both beta-adrenergic agonists and beta-adrenergic antagonists competed with (--)(/sup 3/H)dihydroalprenolol for high affinity (KD 2-4 nM) and low capacity binding sites. The antagonists but not the agonists competed with (--)(/sup 3/H)dihydroalprenolol for lower affinity and higher capacity sites. The present studies were performed in order to characterize the adipocyte beta-adrenergic receptor and distinguish it from low affinity, higher capacity sites which were heat-labile and not stereoselective. When isoproterenol was used to define the nonspecific binding, saturation studies showed a single binding site with a capacity of approximately 100 fmol/mg membrane protein (corresponding to approximately 50,000 sites/adipocyte). Binding was saturated by 10 nM (--)(/sup 3/H)dihydroalprenolol. Approximate KD's of 204 nM were observed. Kinetic analysis of (--)(/sup 3/H)dihydroalprenolol ...
Crystallography and computer modeling have been used to exploit a previously unexplored channel in the glucocorticoid receptor (GR). Highly potent, nonsteroidal indazole amides showing excellent complementarity to the channel were designed with the assistance of the computational technique AlleGrow. The accuracy of the design process was demonstrated through crystallographic structural determination of the GR ligand-binding domain-agonist complex of the D-prolinamide derivative 11. The utility of the channel was further exemplified through the design of a potent phenylindazole in which structural motifs, seen to interact with the traditional GR ligand pocket, were abandoned and replaced by interactions within the new channel. Occupation of the channel was confirmed with a second GR crystal structure of this truncated D-alaninamide derivative 13. Compound 11 displays properties compatible with development as an intranasal solution formulation, ...
This study addresses the mechanism of transport of the H2-receptor antagonist, cimetidine, by the human placenta. A 4-h recycling perfusion of a single placental cotyledon of normal, term, human placenta...Full Text Available
1-Naphthylphthalamic acid (NPA) is a specific inhibitor of polar auxin transport that blocks carrier-mediated auxin efflux from plant cells. To allow identification of the NPA receptor thought to be...Full Text Available
The authors used radioligand binding and studies of cell contraction to characterize muscarinic receptors on dispersed smooth muscle cells from rabbit proximal and distal colon. Cells obtained after serial incubations in collagenase were used to measure binding of tritiated quinuclidinyl benzilate (["3H]QNB). At 37 degree C, specific ["3H]QNB binding was saturable and linearly related to cell number. Nonlinear regression analysis was used to determine the affinity of ["3H]QNB for its receptor. The IC_5_0 for the muscarinic agonists bethanechol and oxotremorine were 80 and 0.57 #mu#M, respectively. Hill coefficients were 0.67 for both, suggesting more complex interaction involving receptors of different affinities. In studies of cell contraction, bethanechol stimulated a dose-dependent decrease in cell length with half the maximal contraction occurring at 100 pM. These results suggest that (1) ...
The temporal development of the effect of THIP (4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol) on the ultrastructure composition and GABA receptor expression in cerebellar granule cells was investigated by quantitative electron microscopy (morphometric analysis) and GABA binding assays. It was found that the cytoplasmic density of smooth endoplasmic reticulum was decreased, while the cytoplasmic density of rough endoplasmic reticulum, Golgi apparatus, vesicles and coated vesicles was greatly enhanced after exposure of the cells to THIP (150 microM) for only 1 hr. In cerebellar granule cells exposed to THIP (150 microM) for 3 hr low affinity GABA receptors were induced. These findings show that the effect of THIP on the ultrastructure composition and GABA receptor expression in cultured cerebellar granule cells may be interrelated and moreover it is likely that the turn-over of GABA receptors is ...
The effects of muscarinic agonists and diisopropylfluorophosphate (DFP) on muscarinic receptor density and muscarinic receptor-mediated responses was assessed in mouse brain and mouse neuroblastoma cells (clone N1E-115). Utilizing the antagonist ({sup 3}H)quinuclidinyl benzilate (({sup 3}H)QNB), there was no difference in the maximal binding capacity (B{sub max}) or equilibrium dissociation constant (K{sub d}) between untreated and 24 hour DFP-treated mice. However, one administration of DFP produced a 24% and 33% decrease in B{sub max} measured by ({sup 3}H)N-methylscopolamine (({sup 3}H)NMS) after 18 and 24 hours which was rapidly reversible within 36 hours after DFP treatment. The loss of ({sup 3}H)NMS binding sites following acute DFP treatment was not accompanied by a change in a particular muscarinic receptor binding conformation. Furthermore, the magnitude of muscarinic ...
Synthetic atrial natriuretic peptide (carperitide) and B-type natriuretic peptide (BNP; nesiritide) are used to treat congestive heart failure. However, despite beneficial cardiac unloading properties, reductions in renal perfusion pressures limit their clinical effectiveness. Recently, CD-NP, a chimeric peptide composed of C-type natriuretic peptide (CNP) fused to the C-terminal tail of Dendroaspis natriuretic peptide (DNP), was shown to be more glomerular filtration rate-enhancing than BNP in dogs. However, the molecular basis for the increased responsiveness was not determined. Here, we show that the DNP tail has a striking effect on CNP, converting it from a non-agonist to a partial agonist of natriuretic peptide receptor (NPR)-A while maintaining the ability to activate NPR-B. This effect is specific for human receptors because CD-NP was only a slightly better activator of rat NPR-A due to the ...
..cap alpha..-2 adrenergic agents have been shown to influence blood pressure, heart rate and other physiological and behavioral functions through interactions with adrenergic pathways within the central nervous system. Pharmacologically relevant ..cap alpha..-1 adrenergic receptors were biochemically characterized and radiohistochemically analyzed in intact tissue sections of the rat and human central nervous system. The anatomical distribution of the ..cap alpha..-2 receptors, labeled with the agonist (/sup 3/H)para-aminoclonidine, verified the concept that ..cap alpha..-2 receptors are closely associated with adrenergic nerve terminals and that ..cap alpha..-2 agents can influence autonomic and endocrine function through an action in the central nervous system. Since ..cap alpha..-2 agonists can influence sympathetic outflow, ..cap alpha..-2 binding sites were closely analyzed in ...
Targeted studies completed include the evaluation of tritiated N-0437, evaluation of "3"5S-cysteamine, evaluation of "1"8F-FDG and initiation of synthetic efforts towards the synthesis of iodinated N-0437 and pergolide analogs. The direction of the project has been changed due to several factors which include the decided lack of favorable experimental results, the excellence of results using muscarinic receptor ligands in pituitary, brain and heart and the contention of the DOE review panel that the original grant proposal was based on flawed assumptions together with their perceived lack of importance to pituitary imaging. In the final year of this grant, three studies will be completed. The first study is the continuation of synthetic efforts to prepare iodinated N-0437 and pergolide analogs for possible use as brain imaging agents. The second study is directed towards completion of biochemical evaluation of various muscarinic receptor ...
Targeted studies completed include the evaluation of tritiated N-0437, evaluation of /sup 35/S-cysteamine, evaluation of /sup 18/F-FDG and initiation of synthetic efforts towards the synthesis of iodinated N-0437 and pergolide analogs. The direction of the project has been changed due to several factors which include the decided lack of favorable experimental results, the excellence of results using muscarinic receptor ligands in pituitary, brain and heart and the contention of the DOE review panel that the original grant proposal was based on flawed assumptions together with their perceived lack of importance to pituitary imaging. In the final year of this grant, three studies will be completed. The first study is the continuation of synthetic efforts to prepare iodinated N-0437 and pergolide analogs for possible use as brain imaging agents. The second study is directed towards completion of biochemical evaluation of various muscarinic ...
Downregulation of anterior pituitary GnRH-receptors by application of a slow release GnRH-implant offers an effective and reversible alternative to surgical castration of the male dog. Aim of the present study was to test the efficacy and the underlying mechanisms of a new non-biodegradable controlled-release device implant (Gonazon, Intervet, containing 18.5mg of the GnRH-agonist Azagly-Nafarelin). Eight male beagle dogs were implanted s.c. at the para-umbilical region. In four dogs implant removal was after 180 days (group 1), in the other four dogs after 365 days (group 2). Eleven weeks after implantation availability of LH was reduced (p<0.0001) by 70%. After an initial increase lasting for about 4 days, testosterone (T) and estradiol (E2) concentrations decreased (p<0.0001) to basal l...
The role of intracellular Ca2+ (Ca2+i) on hematopoiesis was investigated in long term bone marrow cultures using cytokines and agonists of P2 receptors. Cytokines interleukin 3 and granulocyte/macrophage colony stimulator factor promoted a modest increase in Ca2+i concentration ([Ca2+]i) with activation of phospholipase Cgamma, MEK1/2, and Ca2+/calmodulin kinase II. Involvement of protein kinase C was restricted to stimulation with interleukin 3. In addition, these cytokines promoted proliferation (20 times) and an increase in the Gr-1(-)Mac-1+ population with participation of gap junctions (GJ). Nevertheless ATP, ADP, and UTP promoted a large increase in [Ca2+]i, moderate proliferation (6 times), a reduction in the primitive Gr-1(-)Mac-1(-)c-Kit+ population, and differentiation into macrophages without participation of GJ. It is likely that Ca2+i participates as a regulator of hematopoietic signaling: moderate increases in [Ca2+]i would be ...
Full text: The maturation of chicken forebrain is protracted and occurs well after synapse formation providing a good model for studying mechanisms of brain maturation. Using microslices from immature (10 day) and adult chicken forebrain prepared after decapitation, we have examined functional properties of NMDA and AMPA receptors by measuring agonist-induced uptake of "4"5Ca"2"+ . The rate and extent of NMDA induced "4"5Ca"2"+ accumulation decreased during maturation with no change in EC_5_0. The rate and extent of the AMPA induced response also decreased with a 60-fold increase in EC_5_0. However, the total NMDA receptor content did not change as indicated by 3 H-MK801 binding and NR1 immunoreactivity in P2 fractions. Similarly, there was no change in the B_m_a_x of "3H-AMPA, though there was a two-fold increase in K_D, and little or no change in the immunoreactivity in GluR1, 2, 2/3 or 4. These results suggest that it is ...
(-)-N6-(R-4-Hydroxyphenylisopropyl)adenosine (HPIA) was iodinated with NaI and trace /sup 125/I. Mono- and diiodinated reaction products and the starting material were separated by high pressure liquid chromatography and the structures of the reaction products were verified by NMR. (-)-N6-(R-Phenylisopropyl)adenosine (PIA), IHPIA, and I2HPIA decreased rat atrial contractility with ED50 values of 24, 28, and 33 nM, respectively. The contractile effects of these compounds were competitively blocked by theophylline (KI . 7.9 microM), but were not affected by adenosine deaminase. IHPIA also inhibited (-)isoproterenol-stimulated cyclic AMP accumulation in adipocytes with an ED50 (10 nM) and to an extent (83%) nearly identical to PIA. (/sup 125/I)HPIA prepared using carrier-free /sup 125/I bound to adenosine receptors on membranes from rat cerebral cortex, adipocyte ghosts, and heart ventricles. Binding was inhibited stereospecifically by PIA and by other adenosine ...
Several old and new observations suggest the existence in Crohn's disease of a phagocytic disorder of macrophages related to impaired bactericidal activity of host cells or to the presence of invasive bacteria that have developed strategies to counteract macrophage killing. It was recently reported that disordered macrophage cytokine secretion underlies impaired acute inflammation and bacterial clearance in Crohn's disease. Secretion of proinflammatory cytokines by CD macrophages was impaired in response to E. coli or specific Toll-like receptoragonists. In addition, major advances in the etiology of Crohn's disease came from the existence of polymorphism in NOD2 and autophagy-related susceptibility genes (ATG16L1 and IRGM) in patients and from the identification of the presence of adhere...
A hypotheses that mitoxantrone is a competitive antagonist at muscarinic cholinergic receptors was examined in guinea-pig hearts. In isolated left atrial muscle preparations, electrically paced at 2 Hz, the muscarinic agonist, carbachol, caused a concentration-dependent decrease in developed tension. Mitoxantrone caused a parallel right-ward shift of the concentration-response curve for carbachol. Schild plots for the effect of mitoxantrone on the carbachol concentration-response relationship were linear with a slope of 0.88 which was not significantly different from the unity. The right-ward shift of the carbachol concentration-response relationship by mitoxantrone significantly reversed after an additional incubation with a mitoxantrone-free solution, although the reversal was incomplete after a 2-h incubation in the mitoxantrone-free solution. Mitoxantrone caused a concentration-dependent displacement of specific [3H]quinuclidinyl benzilate ...
Endocrine disrupting chemicals can induce malformations and impairment of reproductive function in experimental animals and may have similar effects in humans. Recently, the environmental obesogen hypothesis was proposed, suggesting that environmental chemicals contribute to the development of obesity and insulin resistance. These effects could be related to chemical interaction with nuclear receptors such as the peroxisome proliferator activated receptors (PPARs). As several testosterone-reducing drugs are PPAR activators, we aimed to examine whether four PPAR agonists were able to affect fetal testosterone production and masculinization of rats. Additionally, we wished to examine whether these chemicals affected fetal plasma levels of insulin and leptin, which play important roles in the developmental programming of the metabolic system. Pregnant Wistar rats were exposed from gestation day (GD) 7-21 to diisobutyl ...
Chimpanzee (Pan troglodytes) agonistic screams are graded vocal signals that are produced in a context-specific manner. Screams given by aggressors and victims can be discriminated...Full Text Available
In APCs, presentation by MHC II molecules of the chemically dominant peptide from the protein hen egg white lysozyme (HEL) generates different conformational isomers of the peptide-MHC II complexes (pMHC). Type B pMHCs are formed in early endosomes from exogenous peptides in the absence of H2-DM, whereas in contrast, type A pMHC complexes are formed from HEL protein in late vesicles after editing by H2-DM. Thus, H2-DM edits off the more unstable pMHC complexes, which are not presented from HEL. In this study, we show that type B pMHC complexes were presented from HEL protein only after stimulation of dendritic cells (DC) with TLR ligands or type I IFN. Type I IFN contributed to most TLR ligand-induced type B pMHC generation, as presentation decreased in DC lacking the receptor for type I IFNs (IFNAR1(-/-)). In contrast, presentation of type ...
During the past year, further studies on mAChR were conducted. These studies included verification of the difference in pituitary distribution based on ligand charge. The pituitary localization of TRB. A neutral mAChR ligand, was verified. The lack of QNB blockade of TRB uptake was tested by blockage with scopolamine, another mAChR antagonist and by testing the effect in a different strain of rat. Neither scopolamine or change of rat strain had any effect. We concluded that TRB uptake in pituitary is not a receptor-mediated process. Further studies were conducted with an additional quaternized mAChR ligand: MQNB. Pituitary localization of MQNB, like MTRB, could be blocked by pretreatment with QNB. We have tentatively concluded that permanent charge on a mAChR antagonist changes the mechanism of uptake in the pituitary. Time course studies and the effects of DES on myocardial uptake are reported. A brief report on preliminary results of evaluation of quaternized ...
The thiazolidinedione (TZD) or glitazone class of peroxisome proliferator-activated-#gamma# (PPAR-#gamma#) ligands not only induce adipocyte differentiation and increase insulin sensitivity, but also exert growth inhibitory effects on several carcinoma cell lines in vitro as well as in vivo. In the current study the in vitro effect of four PPAR-#gamma# agonists (ciglitazone, pioglitazone, troglitazone, rosiglitazone) on the cell growth of seven human neuroblastoma cell lines (Kelly, LAN-1, LAN-5, LS, IMR-32, SK-N-SH, SH-SY5Y) was investigated. Growth rates were assessed by a colorimetric XTT-based assay kit. Expression of PPAR-#gamma# protein was examined by immunohistochemistry and Western blot analysis. All glitazones inhibited in vitro growth and viability of the human neuroblastoma cell lines in a dose-dependent manner showing considerable effects only at high concentrations (10 #mu#M and 100 #mu#M). Effectiveness of the glitazones on neuroblastoma cell growth ...
The CYP1A (EROD)-inducing potencies of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 3,3minutes or feet,4,4minutes or feet,5-pentachlorobiphenyl (PCB126) and benzo(k)fluoranthene (B(k)F) were studied in avian embryo livers. TCDD and PCB126 proved to be much more potent as inducers in the chicken than in the other species examined. This finding is consistent with a considerably higher sensitivity of the chicken compared with a number of other avian species to the embryotoxic effects of these compounds. Furthermore, the relative potencies of the tested Ah receptoragonists as CYP1A inducers differed substantially between species. B(k)F and PCB126 showed similar induction potencies in domestic duck embryos, whereas PCB126 is much more potent than B(k)F in the chicken. Also, the potency of PCB126,relative to that of TCDD, was much lower in quail embryo liver in vitro than in chicken embryo liver. Thus, there are large interspecific differences in ...
Atrial natriuretic peptide (ANP) causes relaxation in the opossum lower esophageal sphincter. The effects of dendroaspis natriuretic peptide (DNP) and other natriuretic peptides in the lower esophageal sphincter were not known. We measured the relaxation of transverse strips from the guinea pig lower esophageal sphincter caused by DNP, ANP, brain natriuretic peptide (BNP), C-type natriuretic peptide (CNP), and a natriuretic peptide receptor-C agonist des[Gln^1^8, Ser^1^9, Gly^2^0, Leu^2^1, Gly^2^2]ANP(4-23) amide (cANF(4-23)) in vitro. In resting strips of the guinea pig lower esophageal sphincter DNP and BNP caused marked relaxations. Furthermore, in both sarafotoxin S6c and carbachol-contracted lower esophageal sphincter strips, DNP caused marked and BNP caused moderate, concentration-de...
Unfamiliar male meadow voles induce pregnancy disruptions when they are in physical contact with females, but the presence of the female's original mate partially protects her from the blocking effects of an unfamiliar male. This research examines how behavioral interactions affect pregnancy disruptions by testing two hypotheses: a) original males protect females by reducing the aggressive interactions between females and strange males; and b) administration of clonidine, an alpha 2-adrenergic receptoragonist that decreases activity, aggression, and sexual motivation, will decrease the pregnancy-blocking ability of strange males. Strange males were more aggressive when the original sire was absent, indicating that this change in behavior may be related to their greater success in disrupting pregnancy. When injected with clonidine, males were less likely to block pregnancy, and they showed less contact and mating behavior than when they ...
The purpose of this study was to examine arachidonic acid (AA) metabolism and to characterize the type of adrenergic receptor (AR) involved in the production of the major metabolite of this fatty acid. ({sup 14}C)AA was incubated with GPT-rings and the radiolabelled products were extracted and separated by TLC method. The medium was also assayed for radiolabelled immunoreactive PG's (iPG's) and leukotrienes (LT) B4 and C4 by RIA or Enzyme immunoassay (EIA) after exposure to various AR agonists. ({sup 14}C)AA was incorporated into GPT-rings and metabolized mainly into iPGE2 and smaller amounts into PGF2{alpha}. Trace amounts of PGD2 and 6-keto-PGF1{alpha} but not LTB4 or LTC4 were detected by RIA and/or EIA. Incubation of GPT rings for 15 minutes with isoproterenol and salbutamol resulted in a significant increase of PGE2 synthesis (optimum conc: 10{sup {minus}7}, 10{sup {minus}7}M respectively). In contrast, dobutamine, ...
The purpose of this study was to examine arachidonic acid (AA) metabolism and to characterize the type of adrenergic receptor (AR) involved in the production of the major metabolite of this fatty acid. ["1"4C]AA was incubated with GPT-rings and the radiolabelled products were extracted and separated by TLC method. The medium was also assayed for radiolabelled immunoreactive PG's (iPG's) and leukotrienes (LT) B4 and C4 by RIA or Enzyme immunoassay (EIA) after exposure to various AR agonists. ["1"4C]AA was incorporated into GPT-rings and metabolized mainly into iPGE2 and smaller amounts into PGF2#alpha#. Trace amounts of PGD2 and 6-keto-PGF1#alpha# but not LTB4 or LTC4 were detected by RIA and/or EIA. Incubation of GPT rings for 15 minutes with isoproterenol and salbutamol resulted in a significant increase of PGE2 synthesis (optimum conc: 10"-"7, 10"-"7M respectively). In contrast, dobutamine, norepinephrine, phenylnephrine and xylazine (up to ...
IntroductionChest pain with ST-segment elevation is a rare clinical problem during dobutamine stress testing. Although beta-agonists treatment prior to dobutamine stress testing...Full Text Available
Anthraquinones are widely present in plant kingdom, and clinically used as laxatives. Environmental contaminants, dioxins, develop various adverse effects through transformation of a cytosolic aryl hydrocarbon receptor (AhR). We investigated the effects of 18 anthraquinones and 7 of their structurally related compounds on transformation of the AhR estimated by its DNA-binding activity in the cell-free system. 1,4-Dihydroxyanthraquinone (quinizarin), 1,5-dihydroxyanthraquinone (anthrarufin), 1,8-dihydroxyanthraquinone (danthron), and 5-hydroxy-1,4-naphthoquinone (juglone) strongly suppressed DNA-binding activity of the AhR induced by 0.1 nM 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), with their IC(50) values around 1 muM. On the other hand, anthraquinone, 2,6-dihydroxyanthraquinone (anthraflavic acid), and 2-hydroxy-1,4-naphthalendione (lawsone) showed moderate effects. Quantitative structure-activity relationships analysis demonstrated that hydroxyl groups at C1 or ...
Exogenous adenosine 5{prime}-triphosphate (ATP) mobilized intracellular calcium in human carcinoma A43l cells and in Swiss 3T3 and 3T6 mouse fibroblasts by increasing inositol trisphosphate similar to well down growth factors (platelet-derived growth factor (PDGF), epidermal growth factor (EGF), bradykinin (BK), serum). Calcium mobilization was examined by video imaging of fura-2 fluorescence is single cells, following the radioactive isotope {sup 45}Ca, and monitoring the decrease in fluorescence of cells loaded with chlortetracycline. Uridine 5{prime}-triphosphate, but not other nucleotides, mimicked ATP. Single-cell analysis revealed synchronous responses in 10 sec to ATP, BK or serum, while PDGF (3T3) and EGF (A431) produced slower signals with significant cell-to-cell variation. PDGF desensitized 3T3 cells to ATP and BK added 100 sec later but ATP or BK did not desensitized to PDGF. Homologous desensitization was seen with all agonists. Heterologous ...
The maintenance of a balance between cell gain and cell loss is essential for proper liver function. The exact role of aryl hydrocarbon receptor (AhR) in regulating cell proliferation and apoptosis of liver cells remains unclear, since ligand-dependent activation of AhR has been shown to induce cell cycle arrest, proliferation, differentiation or apoptosis, depending on the cellular model used. AhR can directly interact with retinoblastoma protein in hepatic cells, forming protein complexes that can efficiently block cell cycle progression by inducing G1 arrest, or to induce the expression of inhibitors of cyclin-dependent kinases, such as p271. On the other hand, it has been suggested that AhR could play a stimulatory role in cell proliferation, either directly or by mediating a release from contact inhibition. It is now generally accepted that progenitor cells exist in the liver, are activated in various liver diseases and can form a potential target cell ...
The central benzodiazepine receptor tracer [N-methyl-"1"1C]iomazenil (Ro 16-0154) was synthesized by alkylation of the desmethyl precursor noriomazenil with ["1"1C]methyl iodide. The ["1"1C]CH_3I (prepared by reduction of ["1"1C]CO_2 with LiAlH_4 followed by reaction with HI) was reacted with noriomazenil inN,N -dimethylformamide and Bu_4N"+OH"- for 1 min at 80 deg. C and purified by HPLC (C_1_8, 34% CH_3CN/H_2O, 7 mL/min). The product was obtained with synthesis time 35 #+-# 5 min (mean #+-# SD, n = 7), radiochemical yield (EOB) 36 #+-# 16%, radiochemical purity 99 #+-# 1%, and specific activity 5100 #+-# 2800 mCi/#mu#mol. Absorbed radiation doses were calculated from previously acquired human biodistribution data. The urinary bladder wall received the highest dose (0.099 mGy/MBq) for 4.8 h voiding interval and the effective dose equivalent was 0.015 mSv/MBq. After i.v. injection of ["1"1C]iomazenil in an adult baboon or ...
Histone H2AX phosphorylation on a serine four residues from the carboxyl terminus (producing γH2AX) is a sensitive marker for DNA double-strand breaks (DSBs). DSBs may lead to cancer...Full Text Available
The receptor-associated protein (RAP) is a molecular chaperone that binds tightly to certain newly synthesized LDL receptor family members in the endoplasmic reticulum (ER) and facilitates their delivery...Full Text Available
Structural analysis of an acetylcholine receptor from Torpedo californica leads to a three-dimensional model in which a "monomeric" receptor is shown to contain subunits arranged around a central ionophoretic...Full Text Available
Orphan G protein-coupled receptors (GPCRs) are receptors lacking endogenous ligands. Found by molecular biological analyses, they became the roots of reverse pharmacology, in which receptors are attempted...Full Text Available
Many microbial pathogens recognize oligosaccharides displayed on the surface of host cells as receptors for toxins and adhesins. These ligand-receptor interactions are critical for disease pathogenesis,...Full Text Available
AMPA receptors (AMPARs) are critical for synaptic plasticity, and are subject to alterations based on subunit composition and receptor trafficking to and from the plasma membrane. One of the...Full Text Available
Protein kinase C activity has been identified in the rat brown adipocyte. About 60% of this activity is found in the cytosolic fraction under basal conditions, and 12-O-tetradecanoylphorbol 13-acetate (TPA) causes a rapid shift from the cytosol to the particulate fraction. Norepinephrine and phenylephrine causes a similar redistribution that can be blocked by prazosin but not by alprenolol. {alpha}{sub 1}-Adrenergic agonists cause three- to fivefold stimulation of type 2 iodothyronine 5{prime}-deiodinase activity in brown adipocytes. TPA has no effect on basal deiodinase activity and reduces the response of the enzyme to {alpha}{sub 1}-adrenergic agonists. These results suggest that the translocation of protein kinase C from cytosol to particulate fraction is not sufficient to increase deiodinase activity but can modulate the {alpha}{sub 1}-adrenergic agonist-mediated responses in these cells.
The parathyroid hormone receptor (PTHR) is a class B G protein-coupled receptor that plays critical roles in bone and mineral ion metabolism. Ligand binding to the PTHR involves interactions to both...Full Text Available
Hormone potency depends on receptor availability, regulated via gene expression and receptor trafficking. To ascertain how central leptin receptors are regulated, the effects of leptin challenge, high-fat...Full Text Available
Gastrin-releasing peptide receptor (GRPR), a member of the G protein-coupled receptor superfamily, has been utilized for receptor-mediated targeting of imaging and therapeutic agents; here we extend...Full Text Available
Generation of reactive oxygen species by the NADPH oxidase complex is an important bactericidal weapon of phagocytes. Phorbol myristate acetate (PMA) is a potent agonist for this “respiratory...Full Text Available
In laboratory studies, hamsters (Mesocricetus spp.) exhibit intense male-male aggression, thus making them an excellent model system for studies of the functional and mechanistic...Full Text Available
The main function of white adipose tissue is to store nutrient energy in the form of triglycerides. The mechanism by which free fatty acids (FFA) move into and out of the adipocyte has not been resolved....Full Text Available
The cyclic AMP content of acini, freshly prepared from mammary tissue of lactating rats, was measured during incubation in vitro. Neither adrenergic agonists nor cyclic AMP phosphodiesterase inhibitors...Full Text Available
BackgroundCompared to outbred Sprague Dawley (SD) rats, inbred Brown Norway (BN) rats exhibit less prepulse inhibition of startle (PPI) at long prepulse intervals,...Full Text Available
Electronic energy bands of LaH"2 and NdH"2 have been calculated by the composite-wave variational version of the augmented plane wave method. Crystal potentials for both the hydrides were constructed by the superposition of the atomic potentials of Herman and Skillman. From the band structure data, density of states, joint density of states, optical absorption spectra and Fermi surfaces of these two hydrides have been calculated. The results of the optical studies have been successfully compared with the experimental results of Weaver et al. From the theoretical point of view the present results for LaH"2 have been satisfactorily compared with the results of Gupta et al. Since no theoretical calculation exists for ndH"2, theoretical comparison, in this case, was not possible for ...
A study was made on complex formation of thiosemicarbazide diacetic acid (H_2L) with neodymium (3), holmium (3) and erbium (3) in solutions and formation of complexes of metal: ligand=4:1 composition was revealed. Synthesis conditions were developed and products of LnLClxnH_2O, LnLOHxnH_2O, Na[LnL_2]xnH_2O composition were separated in crystalline state. It was shown, that H_2L behaves in these compounds as tripod ligand with O, O, N, N donor atoms.
Behavior to hydrogen damage caused by stress corrosion in a H_2S medium (SSC) and to intergranular corrosion (IGC) in different mediums, such as oxalic acid (C_2H_2.2H_2O), iron sulphate-50% sulfuric acid (Fe_2(SO_4)_3-50% H_2SO_4), nitric acid (HNO_3), copper sulphate-16% sulfuric acid (CuSO_4.5H_2O-16% H_2SO_4) and cooper sulphate-50% sulfuric acid (CuSO_4.5H_2O-50% H_2SO_4), is studied in an AISI 347 austenitic stainless steel stabilized with 0.61 mass % Nb and hot rolled to a seamless pipe with 273.1 mm in diameter and 18.2 mm in thickness. (Author) 12 refs.
The retinoic acid receptor-related orphan receptors α and γ (RORα (NR1F1) and RORγ (NR1F3)) are orphan nuclear receptors and perform critical roles in regulation of development,...Full Text Available
The gastrin releasing peptide (GRP) receptor is becoming an increasingly attractive target for development of new radiolabeled peptides with diagnostic and therapeutic potential. The attractiveness of the GRP receptor as a target is based upon the functional expression of GRP receptors in several tumors of neuroendocrine origin including prostate, breast, and small cell lung cancer. This concise review outlines some of the efforts currently underway to develop new GRP receptor specific radiopharmaceuticals by employing a variety of radiometal chelation systems.
BackgroundThe pregnane X receptor (PXR; NR1I2), a member of the nuclear receptor superfamily, regulates the expression of metabolic enzymes and transporters involved...Full Text Available
The aspartate receptor involved in chemotaxis is modified by methyl esterification at four distinct glutamate residues during the adaptive response of this receptor. To explain the high degree of specificity...Full Text Available
The adenovirus fiber knob causes the first step in the interaction of adenovirus with cell membrane receptors. To obtain information on the receptor binding site(s), the interaction of labeled cell...Full Text Available
BackgroundThe epidermal growth factor receptor (Egfr) with its numerous ligands has fundamental roles in development, cell differentiation and physiology. Dysfunction of the receptor-ligand...Full Text Available
Chemokine receptors control leukocyte chemotaxis and cell-cell communication but have also been associated with pathogen entry. GPR33, an orphan member of the chemokine-like receptor family,...Full Text Available
1. The effects of stimulation of atrial receptors on hypothalamic neurosecretory cells were investigated in anaesthetized dogs and cats. Atrial receptors were activated by stretching the left and the...Full Text Available
The nicotinic acetylcholine receptor (AChR) controls signal transmission between cells in the nervous system. Abused drugs such as cocaine inhibit this receptor. Transient kinetic investigations indicate...Full Text Available
A specific immunoglobulin, the receptor antibody, can be found in most patients with myasthenia gravis. In order to study the kinetic properties of this antibody, serial determinations of receptor antibody,...Full Text Available
Background:Increasing evidence shows the importance of young age, estrogen receptor (ER), progesterone receptor (PR) status, and HER-2 expression in patients with breast cancers.Patients...Full Text Available
Activation of beta-adrenergic or muscarinic acetylcholine receptors expressed in transfected cells or epidermal growth factor receptors in human keratinocytes produces 15% to 200% changes in cellular...Full Text Available
Reproductive aging in males is characterized by a diminution in sexual behavior beginning in middle age. We investigated the relationships among testosterone, androgen receptor (AR) and estrogen...Full Text Available
The vanilloid receptor-1 (VR1, or transient receptor potential vanilloid-1 receptor, TRPV1) is activated by capsaicin, the key ingredient of hot peppers. TRPV1 was originally described on sensory neurons...Full Text Available
Unlike in normal rabbits, pulmonary rapidly adapting receptors (RARs) in rabbits with chronic mitral regurgitation (MR) do not respond to small changes in extravascular...Full Text Available
Histamine and the histamine receptors are important regulators of a plethora of biological processes, including immediate hypersensitivity reactions and acid secretion in the stomach. In these...Full Text Available
Halothane, chloroform, and carbon tetrachloride, in the vapor and liquid phases, stimulate the water receptor of the blowfly Phormia regina. There are three successive phases of response to long-lasting...Full Text Available
Molar extinction coefficients for the solid solutes in aqueous solutions of some alkaline earth chlorides such as MgCl_2.6H_2O, CaCl_2, SrCl_2.6H_2O and BaCl_2.2H_2O have been determined at 81, 356, 511, 662, 1173 and 1332 keV energies in different concentration using the narrow beam transmission methods. (author)
The utilization of wood-shaving bottom ash (WBA) for the removal of Red Reactive 141 (RR141), an azo reactive dye, was investigated. WBA/H(2)O and WBA/H(2)SO(4) were made by treating WBA with water and 0.1M H(2)SO(4), respectively, to increase adsorption capacity. Adsorption of RR141 from reactive dye solution (RDS) and reactive dye wastewater (RDW) by WBA/H(2)O and WBA/H(2)SO(4) involved the BET surface area and pore size diameter. Properties of adsorbents, effect of contact time, initial pH of solution, dissolved metals and elution studies indicated that the decolorisation mechanism involved both chemical adsorption and precipitation with calcium ions. In addition, the WBA/H(2)SO(4) surface might contain sulphate-cation complexes that ...
By methods of vibrational (infrared, Raman) and PMR spectroscopy, crystallohydrate forms of monosubstituted uranyl orthophosphate have been examined. The vibrational frequencies of the groupings from the compounds were identified. The existence of non-equivalent H_2PO_4"--groups in the substances under investigation was ascertained. It has been suggested that one of them is a bridged group, and the other is the end group. A fragment of the VO_2(H_2PO_4)_2 hydrate structure is given, its main constituents being uranylphosphate chains. The analysis of water vibrations assumes coordination of one mole of H_2O in VO_2(H_2PO_4)_2:3H_2O to uranium, while two other molecules are only hydrogen-bonded with phosphate anions. Absorption within the region of 2100-2550 cm"-"1 is assigned to ...
In order to obtain the electronic structure of leucine (Leu) in aqueous solution, we studied three systems: Leu+7H2O, Leu+8H2O and Leu+9H2O. The results indicated that the system Leu+8H2O was the only choice which was both acceptable and doable: its computational effort was affordable, and it could simulate a main part of the solvent effect on the electronic structure of Leu in solution. Based on the system Leu+8H2O, all-electron, ab initio calculations were performed to construct an equivalent potential of water for the electronic structure of Leu with dipoles. The results showed that the main effect of water on the electronic structure of Leu was raising the occupied states about 0.0824 Ry on average, and broadening the energy gap by 11%. The water effect on the electronic ...
Solar syngas production from CO"2 and H"2O is considered in a two-step thermochemical cycle via Zn/ZnO redox reactions, encompassing: 1) the ZnO thermolysis to Zn and O"2 using concentrated solar radiation as the source of process heat, and 2) Zn reacting with mixtures of H"2O and CO"2 yielding high-quality syngas (mainly H"2 and CO) and ZnO; the ZnO is recycled to the first, solar step, resulting in net reaction @bCO"2 + (1 - @b)H"2O -> @bCO + (1 - @b)H"2. Syngas is further processed to liquid hydrocarbon fuels via Fischer-Tropsch or other catalytic processes. Second-law thermodynamic analysis is applied to determine the cycle efficiencies attainable with and without heat recuperation for varying molar fractions of CO"2:H"2O and solar ...
The properties of ZnO films were investigated as functions of annealing temperatures in H2/Ar and vacuum. The resistivities and mobilities of ZnO films decreased with increase of annealing temperatures in vacuum and H2/Ar ambients. However, the carrier densities of ZnO films increased with increase of annealing temperatures in vacuum and H2/Ar ambients. The resistivities of ZnO2 films annealed at 300degreeC were 2186cm and 798cm in H2/Ar and vacuum ambients, respectively. The resistivities of ZnO films annealed in vacuum and H2/Ar ambients at 600degreeC were similar with 0.040cm and 0.035cm, respectively. The hydrogen donor was more dominant than the oxygen vacancy or Zn interstitial donor in ZnO films annealed in ambient H2/Ar at low ...
It was previously reported that the tritium tracer method is useful for the quantitative consideration of hydrogen behavior in coal during coal liquefaction reaction. Tetralin is excellent hydrogen donating solvent, and is considered as one of the model compounds of coal. In this study, effects of H2S and H2O on the hydrogen exchange reaction between tetralin and gaseous hydrogen labeled by tritium were investigated. It was suggested that the conversion of tetralin and the hydrogen exchange reaction between gaseous hydrogen and tetralin proceed through the radical reaction mechanism with a tetralyl radical as an intermediate product. When H2S existed in this reaction, the hydrogen exchange yield increased drastically without changing the conversion yield. This suggested that the hydrogen exchange reaction proceeds even in the reaction where radical does not give ...
BackgroundThe effects of single or combined histamine H1-receptor and leukotriene CysLT1-receptor antagonism on nasal adenosine monophosphate (AMP) challenge...Full Text Available
BackgroundThe orphan nuclear receptor estrogen-related receptor α (ERRα) is a member of the nuclear receptor superfamily. It was identified through a search for genes...Full Text Available
Although the radioreceptor method is widely used for estrogen receptor assay in human tissue, it has several limitations and a number of alternative methods are being explored. An immunohistochemical method of estrogen receptor assay using a specific antibody to estradiol has been proposed as a suitable alternative. The present study was designed to evaluate the validity of this method in detecting true estrogen receptors in human tumor tissue. Using radioiodinated antibody to estrogen, we have demonstrated that the estrogen antibody can detect the estrogen when it is bound to 4S type receptor but is unable to bind to estrogen when the hormone is bound to 8S type receptor. Our observations suggest that the immunohistochemical method of detection of intracellular cytosolic receptor for estrogen is not a suitable alternative to the currently used radioreceptor ...
An /alpha//sub 2/-adrenergic receptor subtype has been cloned from a human kidney cDNA library using the gene for the human platelet /alpha//sub 2/-adrenergic receptor as a probe. The deduced amino acid sequence resembles the human platelet /alpha//sub 2/-adrenergic receptor and is consistent with the structure of other members of he family of guanine nucleotide-binding protein-coupled receptors. The cDNA was expressed in a mammalian cell line (COS-7), and the /alpha//sub 2/-adrenergic ligand (/sup 3/H)rauwolscine was bound. Competition curve analysis with a variety of adrenergic ligands suggests that this cDNA clone represents the /alpha//sub 2/B-adrenergic receptor. The gene for this receptor is on human chromosome 4, whereas the gene for the human platelet /alpha//sub 2/-adrenergic receptor (/alpha//sub 2/A) lies on chromosome 10. This ...
Insulin receptors on the surface of isolated rat adipocytes were photoaffinity labeled at 12 degrees C with the iodinated photoreactive insulin analogue, 125I-B2 (2-nitro-4-azidophenylacetyl)-des-PheB1-insulin, and the pathways in the intracellular processing of the labeled receptors were studied at 37 degrees C. During 37 degrees C incubations, the labeled 440-kDa insulin receptors were continuously internalized (as assessed by trypsin inaccessibility) and degraded such that up to 50% of the initially labeled receptors were lost by 120 min. Metabolic poisons (0.125-0.75 mM 2,4-dinitrophenol (DNP) and 1-10 mM NaF), which led to dose-dependent depletion of adipocyte ATP pools, inhibited receptor loss, and caused up to 3-fold increase in intracellular receptor accumulation. This effect was due to inhibition of intracellular receptor ...
Oestrogen has been reported to modulate tumour necrosis factor (TNF), interleukin (IL)-1 and IL-6 cytokine levels in human mononuclear cell cultures. In the present study, the effects of exogenous oestrogen...Full Text Available
In the present work the hydrogen desorption properties of nanostructured magnesium hydride (MgH2) synthesized by controlled reactive mechanical milling (CRMM) of elemental Mg powder under hydrogen are investigated. A profound effect of the particle size of synthesized MgH2 hydride on its hydrogen desorption characteristics measured by differential scanning calorimetery (DSC) has been found. All synthesized MgH2 powders are characterized by a double hydrogen desorption peak. Furthermore, below a certain threshold particle size the DSC desorption temperature of the peak doublet starts decreasing rapidly with decreasing of the mean hydride powder particle size (expressed as equivalent circle diameter-ECD). In contrast, the nanograin (crystallite) size of MgH2 does not seem to have apparent effect on the DSC desorption ...
Summary Metabotropic GABAB receptors play a fundamental role in modulating the excitability of neurons and circuits throughout the brain. These receptors influence synaptic transmission by inhibiting presynaptic release or activating postsynaptic potassium channels. However, their ability to directly influence different types of postsynaptic glutamate receptors remains unresolved. Here we examine GABAB receptor modulation in layer 2/3 pyramidal neurons from the mouse prefrontal cortex. We use two-photon laser-scanning microscopy to study synaptic modulation at individual dendritic spines. Using two-photon optical quantal analysis, we first demonstrate robust presynaptic modulation of multivesicular release at single synapses. Using two-photon glutamate uncaging, we then reveal that GABAB r...
A clone encoding a human D{sub 2} dopamine receptor was isolated from a pituitary cDNA library and sequenced. The deduced protein sequence is 96% identical with that of the cloned rat receptor with one major difference: the human receptor contains an additional 29 amino acids in its putative third cytoplasmic loop. Southern blotting demonstrated the presence of only one human D{sub 2} receptor gene. Two overlapping phage containing the gene were isolated and characterized. DNA sequence analysis of these clones showed that the coding sequence is interrupted by six introns and that the additional amino acids present in the human pituitary receptor are encoded by a single exon of 87 base pairs. The involvement of this sequence in alternative splicing and its biological significance are discussed.
The Wind2H2 system is fully functional and continues to gather performance data. In this report, specifications of the Wind2H2 equipment (electrolyzers, compressor, hydrogen storage tanks, and the hydrogen fueled generator) are summarized. System operational experience and lessons learned are discussed. Valuable operational experience is shared through running, testing, daily operations, and troubleshooting the Wind2H2 system and equipment errors are being logged to help evaluate the reliability of the system.
The objectives of this study were to estimate symbiotic nitrogen fixation by two common pasture legumes, Trifolium subterraneum L. and Medicago truncatula Gaertn., and an Australian native legume, Acacia dealbata Link, growing in pots using an indirect isotopic method. This method was also used to calibrate the C2H2 reduction assay of the intact plants. In addition, hydrogen evolution was measured in an attempt to explain the variations in C2H2:N2 ratios between the species. 25 refs.; 1 figure; 4 tabs.
An amphiphilic azobenzene diblock copolymer {2-[4-(4-methoxy phenyl azo)phenoxy]hexyl acrylate co-acrylic acid} was synthesized via reversible addition-fragmentation chain transfer polymerization in a hydrothermal reactor. The products were characterized by 1H-NMR, DSC, GPC and UV-Vis spectroscopy. Different self-assembly behaviors of this amphiphilic diblock copolymer in different organic solvent with different water content were investigated. In THF/H2O solution, the diblock copolymer self-assembled into spheres and the spheres would then change to vesicles with smaller size by increasing the volume of H2O. However, in DMSO/H2O solution, the sizes and morphologies of the self-assembled spheres would not change significantly with an enhanced amount of H2O. Photochromic behaviors of the am...
The fuel cell control problem was studied. Attempts were made to control the output current of the fuel cell by starving it of hydrogen and oxygen. The motivation of this work was to increase efficiency by minimizing waste of fuel. The following findings were obtained: H2 starvation works better than O2 starvation; An optimal H2 to O2 ratio exists for combined H2&O2 starvation; The control scheme for H2&O2 starvation works well for 3 different disturbance tests and at 25 degrees C, 60 degrees C, and 80 degrees C; Fuel cell under reactant starvation is stable for at least 72 hrs.
Proton exchange membrane (PEM) fuel cells are energy sources that have the ... for H2 /02 PEM fuel cells because their catalysts have properties suitable for 0 ...
Aim: Several studies have investigated the expression of the cytokeratins (CKs), vimentin, the epithelial growth factor receptor (EGFR), the oestrogen receptor (ER), and the progesterone...Full Text Available
The GABA-modulating and GABA-mimetic activities of the monoterpenoid thymol were explored on human GABAA and Drosophila melanogaster...Full Text Available
The purpose of this study was to determine whether resistance exercise training-induced reductions in inflammation are mediated via melanocortin 3 receptor expression in obese (BMI 32.7 ± 3.7)...Full Text Available
The plant hormone cytokinin is perceived by membrane-located sensor histidine kinases. Arabidopsis (Arabidopsis thaliana) possesses three cytokinin receptors: ARABIDOPSIS HISTIDINE...Full Text Available
Epidermal growth factor receptor (EGFR)-specific monoclonal antibodies predominantly inhibit colorectal cancer (CRC) growth by interfering with receptor signaling. Recent analyses have shown that patients...Full Text Available
SUMMARYThe cytolytic activity of natural killer (NK) cells is regulated by inhibitory receptors that detect the absence of self molecules on target cells. Structural studies of...Full Text Available
Current concepts of the pathogenesis of sarcoidosis suggest that the expanded numbers of activated T-helper/inducer cells at sites of disease activity result, at least in part, from their proliferation...Full Text Available
Taste cells use multiple signaling mechanisms to generate appropriate cellular responses to discrete taste stimuli. Some taste stimuli activate G protein coupled receptors (GPCRs) that cause calcium...Full Text Available
The normal physiological contraction of the urinary bladder, which is required for voiding, is predominantly mediated by muscarinic receptors, primarily the M3 subtype, with the M2...Full Text Available
G-protein-coupled receptor signalling has been suggested to be voltage dependent in a number of cell types; however, the limits of sensitivity of this potentially important phenomenon are unknown. Using...Full Text Available
Nuclear hormone receptors comprise a characteristic family of transcription factors found in vertebrates, insects and nematodes. Here we show by cDNA and gene cloning that a Cnidarian, Tripedalia...Full Text Available
We previously reported that global deletion of insulin receptor substrate protein 1 (Irs1) extends lifespan and increases resistance to several age-related pathologies in female mice....Full Text Available
1. The structural requirements of an allosteric barbiturate binding site on acetylcholine receptor-rich membranes isolated from Torpedo electroplaques have been characterized by the ability of fourteen...Full Text Available
Growth hormone (GH) has an important role in the regulation of hepatic LDL receptor expression and plasma lipoprotein levels. This investigation was undertaken to evaluate if these effects of GH on...Full Text Available
The neonatal Fc receptor FcRn provides IgG molecules with their characteristically long half-lives in vivo by protecting them from intracellular catabolism and then returning them to...Full Text Available
There is increasing evidence that receptor-mediated events impact one or more stages responsible for tumor development in experimental animals and humans. Although many chemicals and endogenous hormones...Full Text Available
The presence of albumin structures with the capacity to bind to a surface receptor in group C and G streptococci was studied in serum samples from 45 mammalian species representing 15 different orders,...Full Text Available
Epidermal growth factor receptor (EGFR) kinase domain mutations hyperactivate the kinase and confer kinase addiction of the non-small-cell lung cancer (NSCLC) tumor...Full Text Available
Binding of epidermal growth factor (EGF) to the EGF receptor (EGFR) initiates signal transduction, ultimately leading to altered gene expression. Ligand-activated EGFR is also rapidly internalized...Full Text Available
BackgroundBaculovirus, which has a width of 40 nm and a length of 250-300 nm, can display functional peptides, receptors and antigens on its surface by their fusion with a baculovirus...Full Text Available
Epidermal growth factor receptor (EGFR) related therapies – mainly tyrosine kinase inhibitors (TKIs) such as erlotinib and gefitinib, but also monoclonal antibodies targeting EGFR, for example,...Full Text Available
BackgroundPolymorphisms in Epidermal Growth Factor Receptor (EGFR) gene may influence EGFR production and/or activity, thereby modulating susceptibility to lung...Full Text Available
Antagonists for kainate receptors (KARs), a family of glutamate-gated ion channels, are efficacious in a number of animal models of neuropathologies, including epilepsy, migraine pain, and anxiety....Full Text Available
Ionotropic P2X and metabotropic P2Y purinergic receptors are expressed in the central nervous system and participate in the synaptic process particularly associated with acetylcholine, GABA, and glutamate...Full Text Available
Gastrointestinal stromal tumors (GIST) are thought to derive from the interstitial cells of Cajal (ICC) or an ICC precursor. Oncogenic mutations of the KIT or PDGFRA receptor tyrosine kinases are present...Full Text Available
The 37/67-kd laminin receptor, LAMR, is a multifunctional protein that associates with the 40S ribosomal subunit and also localizes to the cell membrane to interact with the extracellular matrix. LAMR...Full Text Available
BackgroundApolipoprotein E (ApoE), a cholesterol carrier associated with atherosclerosis, is a major risk factor for Alzheimer's disease (AD). The low-density lipoprotein receptor...Full Text Available
We have characterized the kinetic response of gene targets throughout the murine genome to transcriptional modulation by the glucocorticoid receptor (GR). In contrast to a model in which multiple genes...Full Text Available
Since a large body of data has suggested a significant role for alpha-fetoprotein (AFP) in the regulation of the immune response at a number of levels, we examined the possibility of a specific receptor...Full Text Available
The receptors for IGF-I (IGF-IR) and insulin (IR) have been implicated in physiological cardiac growth, but it is unknown whether IGF-IR or IR signaling are critically required. We generated mice with...Full Text Available
TCDD and other polyhalogenated aromatic hydrocarbon ligands of the aryl hydrocarbon receptor (AHR) have been classically considered as non-genotoxic compounds because they fail to be directly mutagenic...Full Text Available
Osteoblasts are the primary cells responsible for bone formation. They also support osteoclast formation from bone marrow precursors in response to osteotropic factors by inducing receptor activator...Full Text Available
The murine cytomegalovirus (MCMV) M33 gene is conserved among all betaherpesviruses and encodes a homologue of seven-transmembrane receptors (7TMR) with the capacity for constitutive signaling. Previous...Full Text Available
To study the expression of Fc receptors in human alveolar macrophages (AM), the cells were collected from 12 healthy controls and 22 patients with sarcoidosis and the activity involved in binding to...Full Text Available
TSH receptor (TSHR) plays a central role in regulating thyroid function and is targeted by IgGs in Graves’ disease (GD-IgG). Whether TSHR is involved in the pathogenesis of thyroid associated...Full Text Available
Dysregulation of glutamate neurotransmission may play a role in cognitive deficits in schizophrenia. Manipulation of glutamate signaling using drugs acting at metabotropic glutamate receptors...Full Text Available
The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor that mediates the toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin. However, the role of the AHR...Full Text Available
OBJECTIVEPrevious studies showed that genetic deletion or pharmacological blockade of the receptor for advanced glycation end products (RAGE) prevents the early structural changes...Full Text Available
The cellular receptor for murine coronavirus mouse hepatitis virus (MHV)-A59 is a member of the carcinoembryonic antigen (CEA) family of glycoproteins in the immunoglobulin superfamily. We isolated...Full Text Available
Astrocytes have long been perceived only as structural and supporting cells within the central nervous system (CNS). However, the discovery that these glial cells may potentially express receptors capable...Full Text Available
The extracellular domain of human fibroblast growth factor receptor (XC-FGF-R) was expressed in Escherichia coli. The protein was purified to homogeneity and the interaction with basic fibroblast growth...Full Text Available
Muscarinic cholinergic receptors modulate dopaminergic function in brain pathways thought to mediate cocaine's abuse-related effects. Here, we sought to confirm and ...Full Text Available
Several investigations suggested abnormalities in circadian rhythms are related to the pathophysiology of psychiatric disorders, including drug addiction. Recently, orphan nuclear receptor rev-erb alpha...Full Text Available
Polyclonal antibodies were raised in rabbits by immunization with free peptides corresponding to positions 197-222 of the human beta 1-adrenergic receptor (beta 1 peptide) and the corresponding sequence...Full Text Available
The Wistar Kyoto (WKY) rat strain is a putative genetic model of comorbid depression and anxiety. Previous research showing increased κ-opioid receptor (KOR)...Full Text Available
The acetylcholine receptor from the electric tissue of Torpedo californica is a large, integral membrane protein containing four different types of polypeptide chains. The structure of the purified...Full Text Available
Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors belonging to the nuclear hormone receptor superfamily. Their discovery in the 1990s provided insights...Full Text Available
Single-channel currents from acetylcholine receptor channels of garter snake neuromuscular junctions were recorded using the patch-clamp technique. Low concentrations of acetylcholine or carbamylcholine...Full Text Available
IntroductionVarious multigene predictors of breast cancer clinical outcome have been commercialized, but proved to be prognostic only for hormone receptor (HR) subsets overexpressing...Full Text Available
BACKGROUNDOff-pump coronary artery bypass (OPCAB) surgery is associated with a hypercoagulable state in which the platelet thrombin receptor, protease-activated receptor-1...Full Text Available
Gamma interferon (IFN-γ) and the cellular responses induced by it are essential for controlling mycobacterial infections. Most patients bearing an IFN-γ receptor ligand-binding chain...Full Text Available
P2X1 receptors for ATP contribute to signalling in a variety of cell types and following stimulation undergo rapid desensitisation (within 1 s), and require ∼5 min to recover. In HEK293 cells...Full Text Available
SummaryThe transcriptional co-repressor SMRT utilizes two major receptor interacting domains (RID1 and RID2) to mediate nuclear receptor (NR) signaling through epigenetic modification....Full Text Available
The capacity of bones to adjust their mass and architecture to withstand the loads of everyday activity derives from the ability of their resident cells to respond appropriately to the strains engendered....Full Text Available
BackgroundEstrogen receptors alpha (ERα) and beta (ERβ) are transcription factors (TFs) that mediate estrogen signaling and define the hormone-responsive phenotype...Full Text Available
The expression status of the estrogen receptor alpha (ERα) and that of the epidermal growth factor receptor Her-2/neu frequently correlate inversely in breast cancers. While ERα-dependent...Full Text Available
The 37/67 kDa laminin receptor (LAMR) is a multifunctional protein, acting as an extracellular receptor, localizing to the nucleus, and playing roles in rRNA processing and ribosome assembly....Full Text Available
Dopamine (DA) D3 and D2 receptor mechanisms are implicated in cocaine's abuse-related behavioral effects, but the relative contribution of the two receptor subtypes is only partially characterized....Full Text Available
We have cloned and characterized a 77-kDa oestrogen receptor (ER) from an oestrogen-independent subclone of the MCF-7 human breast cancer cell line. This receptor contains an in-frame, tandem duplication...Full Text Available
Varying coordination modes of the Schiff base ligand H"2L [5-methyl-1-H-pyrazole-3-carboxylic acid (1-pyridin-2-yl-ethylidene)-hydrazide] towards different metal centers are reported with the syntheses and characterization of four mononuclear Mn(II), Co(II), Cd(II) and Zn(II) complexes, [Mn(H"2L)(H"2O)"2](ClO"4)"2(MeOH) (1), [Co(H"2L)(NCS)"2] (2), [Cd(H"2L)(H"2O)"2](ClO"4)"2 (3) and [Zn(H"2L)(H"2O)"2](ClO"4)"2 (4), and a binuclear Cu(II) complex, [Cu"2(L)"2](ClO"4)"2 (5). In the complexes 1-4 the neutral ligand serves as a 3N,2O donor where the pyridine ring N, two azomethine N and two carbohydrazine oxygen atoms are coordinatively active, leaving the ...
The objective of this work is to develop sealing materials for solid oxide fuel cells (SOFCs). A suitable sealant must form strong, dense bonds with SOFC components, be chemically and mechanically compatible with the components, be stable at 1000 degrees C in the operating environment of the SOFC (H_2 and H_2O on the anode side, O_2 on the cathode side), and must be nonconductive.
Four inorganic hydrogen-bonded crystals with second-order nonlinear properties have been discovered: K_4LiH_3(SO_4)_4, Na_2SeO_4#centre dot#H_2SeO_3#centre dot#H_2O, Cs_1_,_5Li_1_,_5H(SO_4)_2 and NH_4HSeO_4. (author)
The H-D exchange reaction has been measured with the D2-H2O system, for Rhodobacter capsulatus JP91, which lacks the hupSL-encoded hydrogenase, and R. capsulatus BSE16, which lacks the HupUV proteins....Full Text Available
The Ni(H_2O)_6 ion is located at an inversion center. Six octahedral water molecules surround the Ni"I"I ion and form hydrogen bonds with the sulfate groups. Each ammonium group binds to the sulfate groups through hydrogen bonds. (orig.).
Plerocercoids of the tapeworm Spirometra mansonoides produce a substance that stimulates growth of experimental hosts. We report purification of plerocercoid growth factor (PGF) to homogeneity by a process involving isolation and solubilization of plerocercoid membranes, isoelectric point selection by chromatofocusing chromatography or preparative isoelectric focusing, and anion-exchange chromatography. A radioreceptor assay (RRA) for human growth hormone (hGH) was used to detect PGF and purity of the 27.5-kDa protein was judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Proteolytic activity was detected in the 27.5-kDa protein by gelatin substrate PAGE. Characterization of PGF as a neutral cysteine proteinase was based on substrate and inhibitor specificities and dependence on pH and thiol-containing reagents. The association of hGH agonist and proteinase activities was shown by comparing RRA and hydrolytic activities in the presence ...
The effect of hydrogen sulfide (H2S) on the chemical looping combustion of coal-derived synthesis gas with bentonite-supported metal oxidesssuch as iron oxide, nickel oxide, manganese oxide, and copper oxideswas investigated by thermogravimetric analysis, mass spectrometry, and X-ray photoelectron spectroscopy (XPS). During the reaction with synthesis gas containing H2S, metal-oxide oxygen carriers were first reduced by carbon monoxide and hydrogen, and then interacted with H2S to form metal sulfide, which resulted in a weight gain during the reduction/sulfidation step. The reduced/sulfurized compounds could be regenerated to form sulfur dioxide and oxides during the oxidation reaction with air. The reduction/oxidation capacities of iron oxide and nickel oxide were not affected by the presence of H2S, but both ...
The dodecanuclear rhenium anionic complex with terminal hydroxo ligands [Re12CS17(OH)6]6? was obtained by the reaction of K6[Re12CS17(CN)6]?20H2O with molten KOH at 300 ?C. The cluster complex was crystallized as a potassium salt from aqueous solution. The reaction between K6[Re12CS17(OH)6]?4H2O and Na2S2O4 in water under reflux results in the formation of the complex Na12[Re12CS17(SO3)6]?48.5H2O. Both new compounds were characterized by single-crystal X-ray diffraction, elemental analyses and IR spectroscopy. The electronic structure of [Re12CS17(OH)6]6? was also elucidated by DFT calculation
The study of chemoattractant receptors on human monocytes had been limited by the lack of a radioligand suitable for use with the small numbers of cells routinely available from human donors. A new synthetic oligopeptide radioligand f(/sup 35/S)Met-leu-phe, with a higher specific radioactivity than was available with the tritiated compound, was used to characterize a chemoattractant receptor on freshly isolated human blood monocytes. These cells bind f(/sup 35/)met-leu-phe with a dissociation constant (KD) of 30.2 +/- 5.6 nM and contain 84,000 +/- 11,300 receptors per cell. f(/sup 35/)met-leu-phe does not bind specifically to blood lymphocytes. The specificity of the oligopeptide receptor on monocytes is indistinguishable from the oligopeptide chemoattractant receptor on human polymorphonuclear leukocytes. Using f(/sup 35/)met-leu-phe, it will now be feasible to study the ...
Mon R2, at a distance of 830 pc, is the only ultracompact HII region (UC HII) where the photon-dominated region (PDR) between the ionized gas and the molecular cloud can be resolved with Herschel. HIFI observations of the abundant compounds 13CO, C18O, o-H2-18O, HCO+, CS, CH, and NH have been used to derive the physical and chemical conditions in the PDR, in particular the water abundance. The 13CO, C18O, o-H2-18O, HCO+ and CS observations are well described assuming that the emission is coming from a dense (n=5E6 cm-3, N(H2)>1E22 cm-2) layer of molecular gas around the UC HII. Based on our o-H2-18O observations, we estimate an o-H2O abundance of ~2E-8. This is the average ortho-water abundance in the PDR. Additional H2-18O and/or ...
Incorporation of /sup 32/P from (gamma-32P)ATP into tyrosine residues of the insulin-like growth factor (IGF)-II receptor was observed in a Triton X-100-insoluble fraction of rat adipocyte plasma membranes. IGF-II receptor phosphorylation proceeded to a stoichiometry of approximately 0.5 mol of phosphate/IGF-II binding site after 10 min of incubation at 4 degrees C. A Km for ATP of 6 microM was calculated for this phosphorylation reaction. Addition of IGF-II caused an approximately 2-fold increase in tyrosine phosphorylation of the IGF-II receptor in this preparation. In contrast, phosphorylation of angiotensin II by the Triton X-100 washed membranes was not stimulated by IGF-II. Incubation of purified receptor immobilized on IGF-II agarose or of receptor-enriched low density microsomal membranes with (gamma-32P)ATP did not result in appreciable incorporation of (/sup 32/P)phosphate ...
The authors have investigated insulin receptor phosphorylation in differentiated cultured BC3H-1 myocytes. As for other insulin-responsive cell systems in partially purified wheat germ agglutinin receptor preparations, insulin stimulates the phosphorylation of its own receptor (95K ..beta..-subunits) in a dose dependent manner (0-400 nM), as identified by immunoprecipitation with antiinsulin receptor antibodies and SDS-PAGE. In the same preparations they show that 12-0-tetradecanyl phorbol acetate (TPA), which in many respect ..beta..-subunits in the same dose dependent manner (0-5 ..mu..M). In addition, antiinsulin receptor antibodies (B-10) also induced phosphorylation of mimics insulin action, also induced phosphorylation of the insulin receptor and HPLC tryptic maps of the /sup 32/P-labeled ..beta..-subunit were identical to those for insulin-induced ...
Molar excess enthalpies and molar excess volumes are reported for the systems H_2O + (C_2H_5)_3N and D_2O + (C_2H_5)_3N at temperatures below and above their lower critical solution temperatures. The molar excess enthalpies are slightly less exothermic for the D_2O system. The molar excess volumes of the H_2O and D_2O systems are within experimental error of one another. Compositions of conjugate solutions estimated from the calorimetric and volumetric measurements agree with those obtained from published liquid-liquid phase diagrams. (Auth.).
Most plans for the disposition of surplus nuclear materials involve storage in sealed containers where the evolution of gases from reactions of adsorbed water could present both pressure and flammability hazards[l] . Despite efforts such as calcining the material to minimize the water content prior to packaging, both residual moisture and readsorbed water may be present in the final containers . Given the anticipated temperature excursions during transportation and storage, this water may thermally desorb, increasing the pressure, and/or thermally dissociate to produce H2 gas, increasing flammability hazards . In addition, the radiation from the nuclear material may induce radiolysis of the water with the likely products being water vapor, H2, 02 and H2O2. In order to better understand the relative importance of the thermal- and radiationinduced chemistry, we ...
l-Carnitine is a critical metabolite indispensable for the metabolism of lipids as it facilitates fatty acid transport into the mitochondrion where b-oxidation occurs. Human astrocytes (CCF-STTG1 cells) and hepatocytes (HepG2 cells) exposed to aluminum (Al) and hydrogen peroxide (H2O2), were characterized with lower levels of l-carnitine, diminished b-oxidation, and increased lipid accumulation compared to the controls. g-Butyrobetainealdehyde dehydrogenase (BADH) and butyrobetaine dioxygenase (BBDOX), two key enzymes mediating the biogenesis of l-carnitine, were sharply reduced during Al and H2O2 challenge. Exposure of the Al and H2O2-treated cells to a-ketoglutarate (KG), led to the recovery of l-carnitine production with the concomitant reduction in ROS levels. It appears that the chann...
The synthesis and structures of three new compounds are reported. [Mg2{PhP(Se,O)Se-Se(O,Se)PPh}2(thf)7(H2O)3] (1), [Mg{PhP(Se,O)Se-Se(O,Se)PPh}(thf)3(H2O)] (2), and [Mn{PhP(Se,O)Se-Se(O,Se)PPh}(thf)3(H2O)] (3) were prepared by treatment of Woollins reagent [PhP(Se)(m-Se)]2 with the corresponding hydrated metal acetates.
Abstract Superoxide dismutase (SOD) is ubiquitous in aerobic organisms and constitutes the first link in the enzyme scavenging system of reactive oxygen species. In the present study, species and organ diversity of SOD activity in a solution and in an in-gel assay system, as well as the effects of hydrogen peroxide (H2O2) on SOD activity, were investigated. In a solution assay system, SOD activity of jackfruit root, shoot, leaves, axes, and cotyledons, of maize embryos and endosperms, of mung bean leaves and seeds, of sacred lotus axes and cotyledons, and of rice and wheat leaves was increased by 1-15 mmol/L H2 O2. However, SOD activity in rice root and seeds, maize roots and leaves, mung bean roots and shoots, and wheat seeds was decreased by 1-15 mmol/L H2O2. The SOD activity of wheat ro...
The effect of chemical pretreatments using NaOH, H2O2, and Ca(OH)2 on Empty Palm Fruit Bunches (EPFB) to degrade EPFB lignin before pyrolyis was investigated. Spectrophotometer analysis proved consecutive addition of NaOH and H2O2 decomposed almost 100% of EPFB lignin compared to 44% for the Ca(OH)2, H2O2 system while NaOH and Ca(OH)2 used exclusively could not alter lignin much. Next, the pretreated EPFB was catalytically pyrolyzed. Experimental results indicated the phenolic yields over Al-MCM-41 and HZSM-5 catalysts were 90wt% and 80wt%, respectively compared to 67wt% yield for the untreated sample under the same set of conditions. Meanwhile, the experiments with HY zeolite yielded 70wt% phenols.
The Advanced MAPLE is a research reactor design under development as a high-flux neutron source. The main performance goals for the reactor are a high peak thermal neutron flux in a heavy-water reflector tank, and a high average fast neutron flux in a central irradiation facility, with a maximum linear fuel rod rating of less than 120 kW/m. This study investigated the neutronic and reactor design consequences of the use of H_2O coolant as opposed to D_2O. The neutronics results, and several other considerations, indicate that H_2O coolant has a number of advantages. It is suggested that the H_2O coolant option be considered in the design of the Advanced MAPLE reactor. (L.L.) 9 refs., 4 figs., tab.
The systems CH_3COHNC_6H_4CH_3-HI-H_2O, CH_3CONHC_6H_4CH_3-HIO_3-H_2O, CH_3CONHC_6H_4CH_3-H_5IO_6-H_2O have been studied by the solubility method. It has been ascertained that the systems containing periodic and iodic acids are referred to systems of simple eutonic type. Formation of compound of o-methylacetanilide with iodic acid of equimolecular composition has been proved. Concentrational boundaries of its existence in solutions have been established, its certain physicochemical characteristics being determined.
A sensitive hydrogen peroxide (H2O2) sensor was fabricated based on graphene-Pt (GN-Pt) nanocomposite. The GN-Pt was synthesized by photochemical reduction of K2PtCl4 on GNs, and characterized by atomic force microscope (AFM), transmission electron microscope (TEM), and energy-dispersive X-ray spectroscopy (EDS). Electrochemical investigations indicated that the GN-Pt exhibited a high peak current and low overpotential towards the reduction of H2O2. The GN-Pt modified glass carbon electrode displayed a wide linear range (2-710mM), low limit of detection (0.5mM) and good selectivity for detection of H2O2 with a much higher sensitivity than that of Pt nanoparticles or graphene modified electrode.
A mechanism is proposed for the previously observed [1] jump in erythrocyte fluidity through a microcapillary 1.3 ?m in diameter at a temperature of 36.6?0.3?C. Our interpretation is based on the experimental evidence both for existence of ortho and para H2O isomers in water and on spin-selective interaction of proteins with para H2O isomers as hydration shells of biomolecules are being formed [2]. It is important that the formation of hydration shells of proteins and DNA in aqueous solutions is accompanied by an increase in the Brillouin shift to 0.4 cm?1 (?0.25 cm?1 in water), which points to the formation of icelike structures. We believe that the coincidence of the translational energy kT of the Brownian motion and the energy of the rotational quanta for the 313?202 transition of para ...
The authors have been involved for the last few years in developing high affinity sigma-receptor-specific radiopharmaceuticals for use in nuclear medicine. They recently demonstrated that sigma-1 receptors are expressed in human melanoma cells and that sigma receptors could be used as external markers for non-invasive imaging. In order to determine the presence of sigma receptors in other human tumors they have screened numerous non-small cell lung carcinoma, melanoma and breast cancer cell lines. All of these cell lines expressed high sigma receptor densities using commercially available ["3H]-(+)-pentazocine or ["3H]DTG tritiated sigma ligands. Therefore, a sigma ligand with high affinity in both sigma-1 and sigma-2 subtype pharmacological assays could be potentially useful for imaging a variety of primary and metastatic sites of various origins. The authors describe recent ...
Somatogenic hormones play an important role in regulation of receptors for prolactin (PRL) and estrogen. Plerocercoids of the tapeworm, S. mansonoides produce a factor which mimics some, but not all of the actions reported for GH. Intact female rats were subjected to a constant infusion of plerocercoid growth factor (PGF) via a subcutaneous infection for two weeks to determine if PGF influences receptors for PRL, GH or estradiol. The rate of weight gain in the PGF-treated rats was accelerated in spite of a marked reduction in serum GH. Partially-purified PGF specifically displaced [125I]hGH from rat liver receptors but microsomes prepared from rats treated with PGF specifically bound significantly less [125I]hGH than microsomes from control rats. The reduction in [125I]hGH binding was not due to occupancy or to a change in affinity but to a suppression in receptor concentration. Scatchard analysis of ...
Methylxanthines and their derivatives are antagonists at cell surface adenosine receptors. They report here a systematic study of xanthine structure-activity relationships which compares potency at two adenosine receptor subtypes, R/sub a/ and R/sub i/. Adenylate cyclase stimulation (R/sub a/ in platelet membranes) and inhibition (R/sub i/ in adipocyte membranes) were used as models of receptor activation. K/sub i/ values were obtained by Schild analysis. The orders of potency of the xanthines to attenuate the effects of adenosine analogues were similar to those previously reported. Earlier work utilizing radioligand binding (R/sub i/ and (/sup 3/H) cAMP formation (R/sub a/) claimed that IIX and PACPX are at least 10 and 400 fold, respectively, more potent at R/sub i/ than at R/sub a/. However, in their assays which utilize modulation of receptor-coupled adenylate cyclase, the xanthines show little ...
vehicles including the H2-A rocket and the space shuttle. .... The vacuum can's main function is to provide a high vacuum so that the science experiment and its sensors ... EMI-shielded power conversion from the incoming ISS power supply. 4. ...
The pentenary compound semiconductor Cu(In,Ga)(Se,S)2 is one of the most attractive materials for high-efficiency solar cells due to its tunable band gap to match well the solar spectrum. In this study, semiconducting Cu(In,Ga)(Se,S)2 thin films were prepared by a classical two-step growth process, which involves the selenization and/or sulfurization of In/Cu?Ga precursor. During the precursor formation step metallic In/Cu?Ga alloys were deposited onto the Mo-coated soda-lime glass substrates by DC magnetron sputter process. The respective precursors were subsequently reacted with H2Se and/or H2S gasses, at elevated temperatures. By optimizing the selenization parameters, such as the gas concentrations, reaction time, reaction temperature, and the flow of H2Se and H2S, high quality, single...
One regenerative path to produce hydrogen is the photo-biological hydrogen production by the green micro-alga Chlamydomonas reinhardtii. This process can be divided into three phases: a growth phase, a phase in which the algae adapt from oxygen production and CO2-fixation to fermentative H2 production, and a phase in which H2 is produced. In a research project carried out at Ruhr-Universitat Bochum, a new developed flat panel bioreactor was investigated. A system analysis was conducted and energetic and environmental key figures were determined. The intention of this assessment on a very early technological stage was to collect first technical data in order to classify the current technological status of the photo-biological H2 production to identify future potentials and to uncover weaknesses. For this reason the key figures were evaluated for the status quo ...
The search for alternative energy supplies continues since the oil crisis of 1973. One energy vector is dihydrogen, H_2. Of the group VI hydrides, water has been the focus of most studies in harnessing solar energy and generating H_2. Two basic photochemical strategies have been employed: molecular photocatalytic systems, and semiconductor based photocatalytic systems. The results have not met with the euphoric expectations of the mid-1970's because of the difficulties encountered in H_2O splitting (E"0 S"2 "-/S = + 0.51 eV, NHE) is another vehicle tapped as a potential source of H_2. Heterogeneous photocatalysis utilizing semiconductor particulates and sunlight as the photon source has been successful with interesting quantum efficiencies. To this end, novel photocatalytic devices have been developed; one of these uses ...
We describe the characteristics of the rapidly rotating molecular disk in the nucleus of the mildly active galaxy NGC4258. The morphology and kinematics of the disk are delineated by the point-like...Full Text Available
Plasma nitriding in glow discharge is a process of modifying surface properties of a material by which surface hardness, corrosion resistance, fatigue strength etc. of a material can be improved
Normal cells, both in vivo and in vitro, become quiescent after serial cell proliferation. During this process, cells can develop immortality with genomic instability,...Full Text Available
It is well established from experiments in premixed, laminar flames, jet-stirred reactors, flow reactors, and batch reactors that SO2 acts to catalyze hydrogen atom removal at stoichiometric and reducing conditions. However, the commonly accepted mechanism for radical removal, SO2 + H(+M) reversible arrow HOSO(+M), HOSO + H/OH reversible arrow SO2 + H-2/H2O, has been challenged by recent theoretical and experimental results. Based on ab initio calculations for key reactions, we update the kinetic model for this chemistry and re-examine the mechanism of fuel/SO2 interactions. We find that the interaction of SO, with the radical pool is more complex than previously assumed, involving HOSO and SO, as well as, at high temperatures also HSO, SH, and S. The revised mechanism with a high rate constant for H + SO2 recombination and with SO + H2O, rather than SO2 + ...
Magnetic moment and susceptibility of single crystals of rare earth tartrates of the type R(C4H4O6)(C4H5O6)3H2O (where R = Gd, Ho, and Yb), using a vibration sample magnetometer are reported. The experimental values of molar susceptibilities for Gd(C4H4O6)(C4H5O6)3H2O, Ho(C4H4O6)(C4H5O6)3H2O, and Yb(C4H4O6)(C4H5O6)3H2O are 2.58x10-2, 4.66x10-2, and 8.03x10-3 (in cgs em units), respectively. The calculated effective magnetic moments are in good agreement with the theoretical predictions on rare earth ions.
Ultra-luminous infrared galaxies are among the most luminous objects in the local universe and are thought to be powered by intense star formation. It has been shown that in these objects the rotational spectral lines of molecular hydrogen observed at mid-infrared wavelengths are not affected by dust obscuration, leaving unresolved the source of excitation of this emission. Here I report an analysis of archival Spitzer Space Telescope data on ultra-luminous infrared galaxies and demonstrate that star formation regions are buried inside optically thick clouds of gas and dust, so that dust obscuration affects star-formation indicators but not molecular hydrogen. I thereby establish that the emission of H_2 is not co-spatial with the buried starburst activity and originates outside the obscured regions. This is rather surprising in light of the standard view that H_2 emission is directly associated with ...
Laser holographic interferometry and pressure measurements are presented for the effects of rib-to-duct height ratio (H/2B), rib pitch-to-height ratio (Pi/H), and Reynolds number (Re) on the spatially periodic-fully developed turbulent heat transfer and friction in a rectangular duct of width-to-height ratio of 4:1 with an array of ribs detached from one wall at a clearance to rib-height ratio of 0.38. The ranges of H/2B, Pi/H, and Re examined were 0.13 to 0.26, 7 to 13, and 5 {times} 10{sup 3} to 5 {times} 10{sup 4}, respectively. The difference in the H/2B dependence of the thermal performance between the detached and attached solid-rib array is documented H/2B = 0.17 and Pi/H = 10 are found to provide the best thermal performance for the range of parameters tested. Compact heat transfer and friction correlations are ...
The conditions of production and the stability regions have been studied for the following crystallohydrates of trisubstituted uranyl orthophosphates: (UO_2)_3(PO_4)_2x6H_2O, (UO_2)_3(PO_4)_2x4H_2O, and (UO_2)_3(PO_4)_2xH_2O. Their thermal stability has been studied. It is shown that thermal dehydration of high-water hydrates at 220-240 deg C gives (UO_2)_3(PO_4)_2xH_2O. The anion composition and crystal structure of the compound remain constant up to 1000 deg C. The mixture of the composition of U_3O_8xU_3(PO_4)_4 is the final product of decomposition at 1000 deg C. The thermodynamic constants of dehydration processes have been calculated. A conclusion has been made about the polymer structure of the compound in which water is located between the uranylphosphate layers.
Introduced herein is microwave irradiation for the adsorption and desorption of environmental pollutants. Microwaves may be used in two ways, other than through elevation of temperature of a system as a whole with the adsorbent such as activated carbon serving as the heating medium. The first is the application by which desorption is caused to take place of specified molecules. For example, zeolite that has adsorbed water is regenerated when it is irradiated with microwaves in a stream of cooling gas. This is because only the moisture is heated since zeolite is a non-carbon adsorbent that absorbs microwaves but a little. Another case is reported in which microwaves are utilized to desorb H2S, H2O, CO, etc., from molecular sieves. In the second application, coexisting materials different in absorptivity are exposed to irradiation. The adsorption of microwave-absorbent materials is inhibited while that of ...
May 31, 2011 ... Synthesis and Structural Characterization of a Novel Indium Mercapto Derivative [Clln(SCH2(CO)O)2]2-[(4-MepyH)2]2+. 284. System Mass ...
The muscarinic receptor binding of trazodone, a new nontricyclic antidepressant, was compared with established tricyclic antidepressants. The ability to inhibit the binding of [3H]-quinuclidinyl benzilate...Full Text Available
SummaryMammalian iron homeostasis is regulated by the interaction of the liver-produced peptide hepcidin and its receptor, the iron transporter ferroportin. Hepcidin binds to...Full Text Available
SUMMARYTestosterone and estrogen are essential for male behaviors in vertebrates. How these two signaling pathways interact to control masculinization of the brain and behavior...Full Text Available
The rejection thresholds of Phormia regina Meigen for twenty-four glycols have been determined. A definite relationship between the concentration of the test material and the distribution...Full Text Available
There is considerable evidence that purines are vasoactive molecules involved in the regulation of blood flow. Adenosine is a well known vasodilator that also acts as a modulator of the response to...Full Text Available
Cellular actions of thyroid hormone may be initiated within the cell nucleus, at the plasma membrane, in cytoplasm, and at the mitochondrion. Thyroid hormone nuclear receptors (TRs) mediate the biological...Full Text Available
Laron syndrome (LS) is an autosomal recessively inherited condition characterized by insensitivity to endogenous and exogenous GH. Affected individuals have severe episodes and other characteristic features. GH receptor gene mutations are present in all affected individuals in whom molecular studies have been reported. The GH receptor is a plasma membrane-spanning protein in which the extracellular domain binds circulating GH and the intracellular domain interacts with the JAK-2 kinase and possibly other intracellular signaling molecules. GH receptor dimerization occurs on GH binding and is thought to be required for normal signal transduction. We have studied the GH receptor genes of four unrelated individuals affected with LS from the United States, Italy, Saudi Arabia, and India. We have identified four different missense mutations that alter consecutive amino acids 152 to 155 in or near the ...
A study was made of the kinetics of L-(/sup 3/H)quinuclidinyl benzilate binding with membrane-bound muscarine cholinoreceptors from the rat brain. Determination was made of the rate constants of this process, and constants as a function of ligand concentration was investigated, indicating that there is a complex mechanism of interaction of antagonists with muscarine receptor. With up to 3.5 nM concentrations of L-(/sup 3/H)quinuclidinyl benzilate, the binding reaction occurs in two stages: rapid equilibrated binding is followed by a slow process of conformational isomerization of the receptor-ligand complex. At higher ligand concentrations, there is additional drastic increase in constant of rate of ligand binding a new plateau is reached. Such dependence of rate constant on ligand concentration is indicative of the cooperative nature of interaction between antagonists and muscarine receptors. This is possible if there are ...
The tetrapeptide KDEL is commonly found at the C terminus of soluble proteins of the endoplasmic reticulum (ER), and it contributes to their localization by interacting with a receptor that recycles...Full Text Available
BackgroundWhereas there is increasing evidence that loss of expression and/or function of the thyroid hormone receptors (TRs) could result in a selective advantage for tumor development,...Full Text Available
This paper describes attempts to isolate and characterize glycosaminoglycan (GAG)-binding molecules on the surface of lymphocytes and lymphoma cell lines and relate their expression to splenic and lymph...Full Text Available
OBJECTIVES:To investigate the effect of opioid receptor blockade on the myocardial protection conferred by chronic exercise and to compare exercise training with different strategies...Full Text Available
Carbohydrate-directed endocytosis is mediated by a receptor, the hepatic binding protein; it is responsible for the clearance of galactose-terminated glycoproteins from the circulation. This process...Full Text Available
Measurements of the taste thresholds of blowflies for a wide variety of carbohydrates, presented individually and in combination, showed that the stimulating effects of the compounds are not always...Full Text Available
The synthesis and structural characterization of a novel In(III) complex is described. The reaction between InCl3 with sodium mercapto-acetic acid, (NaSCH2(CO)OH) in 4-methylpyridine, (CH3(C5H5N), (4-Mepy)) at 25 C affords (ClIn(SCH2(CO)O)2)2- ((4-MepyH)2...
Six uranyl coordination compounds, UO_2(OH)(PYCA) (1), UO_2(PYCA)_2(H_2O).2H_2O (2), UO_2(PIC)_2 (3), UO_2(H_2O)_2(NIC)_2 (4), UO_2(OH)(HINIC)(INIC) (5), and UO_2(PYTAC)_2(H_2O)_2 (6) were grown as single crystals via hydrothermal synthesis (PYCA - pyrazine-2-carboxylate, PIC - picolinate, NIC - nicotinate, INIC - iso-nicotinate, and PYTAC - 2-(pyridin-4-yl)thiazole-5-carboxylate) to study their optical properties. All six compounds have been identified via single crystal X-ray diffraction and fully characterized via powder X-ray diffraction, infrared spectroscopy, UV-Vis spectroscopy, and fluorescence spectroscopy. Three of the complexes, 1, 3, and 6, represent new structures, and their synthesis and structural characterization is detailed within. The structures of 2, 4, and 5 have previously been reported in the ...
Crystallization points of aqueous solution of the systems M(ClO_4)_2-H_2O (M"2 = Mg"2"+, Ca"2"+, Sr"2"+, Ba"2"+), depending on the salt concentration, were identified by visual-polythermal method. Relying on model notions on the structure of the electrolyte solutions, specific features of strontium perchlorate solubility polytherm and concentration dependence of the relative dynamic viscosity of the salt aqueous solutions are discussed
Thermal desorption spectroscopy (TDS) was used to study outgassing from polycrystalline SiGe (poly-SiGe), SiC and SiO"2 films used for poly-SiGe-based MEMS thin film vacuum package technology. Primary desorption products were found to be H"2, H"2O and CO"2. The CO"2 outgassing could be correlated with CF"4 plasma interface cleaning used for thick SiGe PECVD, which can leave carbon at the CF"4-plasma-cleaned interface.
Abstract Despite reduced sympathetic activity below the level of a spinal cord injury (SCI), venoconstriction during autonomic dysreflexia increases venous return to the heart. Here, contractions of isometrically mounted tail veins from rats with spinal transection at T4 performed 8???10 weeks earlier are compared with those from sham-operated rats. After SCI, lumen diameter was reduced by ?30% and the contractions evoked by electrical stimulation of the perivascular axons were larger than control. This augmentation of neurovascular transmission was not associated with enhanced sensitivity to ?-adrenoceptor agonists or to adenosine-5?-triphosphate (ATP) although contractions to depolarization with K+ were larger after SCI. The percentage reduction in nerve-evoked contraction after SCI prod...
It is uncertain if downregulation of ?-adrenoceptor signaling pathway is promoted by an enhanced adrenergic tone at an early stage of cardiac disease, or it develops secondary to detrimental local myocardial changes in advanced heart failure. We examined the integrity of ?-adrenoceptor signaling pathway upon chronic infusion of isoproterenol, a ?-adrenoceptor agonist, at a dose producing no structural left ventricular (LV) remodeling and systolic dysfunction. Subcutaneous isoproterenol infusion (400??g?kg?1?h?1 over 16?days) to guinea pigs using osmotic minipumps produced no change in cardiac weights, LV internal dimensions, myocyte cross-sectional area, extent of interstitial fibrosis, and basal contractile function. Isolated, perfused heart preparations from isoproterenol-treated guinea ...
Carbon monoxide can be produced in severe accidents from interaction of ex-vessel molten core with concrete. Depending on the particular core-melt scenario, the type of concrete and geometric factors affecting the interaction, the quantities of carbon monoxide produced can vary widely, up to several volume percent in the containment. Carbon monoxide is a combustible gas. The carbon monoxide thus produced is in addition to the hydrogen produced by metal-water reactions and by radiolysis, and represents a possibly significant contribution to the combustible gas inventory in the containment. Assessment of possible accident loads to containment thus requires knowledge of the combustion properties of both CO and H_2 in the containment atmosphere. Extensive studies have been carried out and are still continuing in the nuclear industry to assess the threat of hydrogen in a severe reactor accident. However the contribution of carbon monoxide to the ...
SummaryThe receptors for the second messenger InsP3 comprise a family of closely related ion channels that release Ca2+ from intracellular stores, most prominently...Full Text Available
BackgroundCannabinoids represent unique compounds for treating tumors, including astrocytomas. Whether CB1 and CB2receptors mediate this therapeutic effect...Full Text Available
To investigate mechanisms responsible for positive and negative transcriptional control, the authors have utilized two types of promoters that are diffferentially regulated by thyroid hormone (T{sub 3}) receptors. Promoters containing the palindromic T{sub 3} response element TCAGGTCA TGACCTGA are positively regulated by the T{sub 3} receptor after the administration of T{sub 3}, whereas otherwise identical promoters containing the estrogen response element TCAGGTCA CTG TGACCTGA can be regulated negatively; converse effects are observed with the estrogen receptor. They describe evidence that the transcriptional inhibitory effects of the T{sub 3} or estrogen receptors on the estrogen or T{sub 3} response elements, respectively, are imposed by amino acid sequences in the C'-terminal region that colocalize with dimerization and hormone-binding domains and that these sequences can transfer ...
BackgroundThe status of estrogen receptor-α (ERα) is critical to the clinical prognosis and therapeutic approach in breast cancer. ERα-negative breast cancer...Full Text Available
1. The induction of long-term potentiation (LTP) was investigated in the rat dentate gyrus in the presence of ryanodine, an agent which is known to selectively bind to the ryanodine receptor (RyR) Ca2+...Full Text Available
The Epstein-Barr virus protein, LMP1, is a functional mimic of the cellular receptor CD40, but signals to B lymphocytes in an amplified and sustained manner compared to CD40. LMP1 contributes...Full Text Available
1. The effects on micturition of RP 67,580, a selective NK1 receptor antagonist, and SR 48,968, a highly, potent antagonist at NK2 receptor sites, given intrathecally (i.t.) or intra-arterially (i.a.)...Full Text Available
We have previously described an allelic polymorphism in the V beta 6.1 T-cell receptor gene. The V beta 6.1B allele is associated with disease in a subgroup of patients with juvenile rheumatoid arthritis....Full Text Available
Here, we provide the first study of prolactin (PRL) and prolactin receptor (PRLR) expression during the nonseasonal murine hair cycle, which is, in contrast to sheep, comparable with the human scalp...Full Text Available
Airway ciliated cells express an ATP-gated P2X receptor channel of unknown subunit composition (P2Xcilia) which is modulated by Na+ and by long exposures to ATP. P2Xcilia...Full Text Available
AimsTo characterize the pharmacokinetics of terbogrel, a new combined thromboxane A2 (TxA2) receptor and synthase inhibitor, in healthy human subjects after...Full Text Available
The effects of neuroactive steroids on the function of GABAAreceptors were studied using cell-attached records of single channel activity recorded from HEK293 cells transfected with α1...Full Text Available
Although peroxisome proliferator-activated receptor alpha (PPARα) is closely associated with myocardial fatty acid metabolism, the pathophysiological role of PPARα in myocardial infarction...Full Text Available
Peroxisome proliferator activated receptor-{gamma} (PPAR{gamma}) regulates metabolic homeostasis and adipocyte differentiation, and it is activated by oxidized and nitrated fatty acids. Here we report the crystal structure of the PPAR{gamma} ligand binding domain bound to nitrated linoleic acid, a potent endogenous ligand of PPAR{gamma}. Structural and functional studies of receptor-ligand interactions reveal the molecular basis of PPAR{gamma} discrimination of various naturally occurring fatty acid derivatives.
Asialoorosomucoid (ASOR) is internalized and degraded by HepG2 cells after binding to the asialoglycoprotein (ASGP) receptor, internalization through the coated pit/coated vesicle pathway, and trafficking to lysosomes. Primaquine, an 8-aminoquinoline antimalarial compound, inhibits ASOR degradation at concentrations greater than 0.2 mM by neutralizing intracellular acid compartments. This leads to alterations in surface receptor number, receptor-ligand dissociation, and receptor recycling. We have investigated the effects of primaquine on 125I-ASOR uptake and degradation as a function of primaquine concentration and duration of exposure. Concentrations below those required for neutralization of acidic compartments block 125I-ASOR degradation in HepG2 cells and lead to intracellular ligand accumulation. This effect is maximal at 80 microM primaquine. The intracellular 125I-ASOR is undegraded, dissociated ...
Asialoorosomucoid (ASOR) is internalized and degraded by HepG2 cells after binding to the asialoglycoprotein (ASGP) receptor, internalization through the coated pit/coated vesicle pathway, and trafficking to lysosomes. Primaquine, an 8-aminoquinoline antimalarial compound, inhibits ASOR degradation at concentrations greater than 0.2 mM by neutralizing intracellular acid compartments. This leads to alterations in surface receptor number, receptor-ligand dissociation, and receptor recycling. We have investigated the effects of primaquine on 125I-ASOR uptake and degradation as a function of primaquine concentration and duration of exposure. Concentrations below those required for neutralization of acidic compartments block 125I-ASOR degradation in HepG2 cells and lead to intracellular ligand accumulation. This effect is maximal at 80 microM primaquine. The intracellular 125I-ASOR is undegraded, dissociated ...
(3H)Cyclofoxy (CF: 17-cyclopropylmethyl-3,14-dihydroxy-4,5-alpha-epoxy-6-beta-fluoromorp hinan) is an opioid antagonist with affinity to both mu and kappa subtypes that was synthesized for quantitative evaluation of opioid receptor binding in vivo. Two sets of experiments in rats were analyzed. The first involved determining the metabolite-corrected blood concentration and tissue distribution of CF in brain 1 to 60 min after i.v. bolus injection. The second involved measuring brain washout for 15 to 120 s following intracarotid artery injection of CF. A physiologically based model and a classical compartmental pharmacokinetic model were compared. The models included different assumptions for transport across the blood-brain barrier (BBB); estimates of nonspecific tissue binding and specific binding to a single opiate receptor site were found to be essentially the same with both models. The nonspecific binding equilibrium constant varied ...
The immunolocalization of the low density lipoprotein receptor-related protein 1 (LRP1) and its ligand alpha 2-Macroglobulin (α2M) was examined in tissues from human donor...Full Text Available
Growth differentiation factor-9 (GDF-9), an oocyte-secreted member of the transforming growth factor β superfamily, progesterone receptor, cyclooxygenase 2 (Cox2; Ptgs2), and the EP2 prostaglandin...Full Text Available
Backgroundβ2-Adrenergic receptors (β2AR) play important regulatory roles in a variety of cells and organ systems and are important therapeutic...Full Text Available
An unusual S1-nuclease sensitive microsatellite (STMS) has been found in the single copy, rat polymeric immunoglobulin receptor gene (PIGR) terminal exon. In Fisher rats, elements within or beyond the...Full Text Available
Using an anti-receptor mAb that blocks the attachment of echovirus 7 and related viruses (echoviruses 13, 21, 29 and 33), we have isolated a complementary DNA clone that encodes the human decay-accelerating...Full Text Available
The aim of this study was to investigate cumulus expansion, nuclear maturation and expression of connexin 43, cyclooxygenase-2 and FSH receptor transcripts in equine cumuli oophori during in vivo and...Full Text Available
Bovine leukemia virus (BLV), a retrovirus related to human T-cell leukemia virus types 1 and 2, can induce persistent nonneoplastic expansion of the CD5+ B-cell population, termed...Full Text Available
T-cell activation requires the influx of extracellular calcium, although mechanistic details regarding such activation are not fully defined. Here, we show that P2X7receptors play a key...Full Text Available
This study focuses on the effects of long-term renin-angiotensin system suppression and/or incretin mimetic therapies on the regulation and binding affinity of GLP-1 to its receptor in the coronary...Full Text Available
It has been postulated that fetal vascular abnormalities in aryl hydrocarbon receptor null (ahr−/−) mice may alter cardiovascular homeostasis in adulthood....Full Text Available
Adenosine regulates a wide variety of physiological processes via interaction with one or more G-protein-coupled receptors (A1R, A2AR, A2BR, and A3R)....Full Text Available
This report investigates acute changes in the sensitivity of 5-HT1Areceptors in dorsal raphe (dr) neurons in response to elevated serotonin. DR neurons were isolated from adult rats...Full Text Available
α1-Fetoprotein transcription factor (FTF), also known as liver receptor homolog 1 (LRH-1) is highly expressed in liver and intestine, where it is implicated in the regulation...Full Text Available
The ζ chain-associated 70-kDa protein (ZAP-70) of tyrosine kinase plays a critical role in T cell receptor-mediated signal transduction and the immune response. A high level of ZAP-70 expression...Full Text Available
By improving the currently used lactoperoxidase method, we were able to obtain radioiodinated chicken luteinizing hormone (LH) that shows high specific binding and low nonspecific binding to a crude plasma membrane fraction of testicular cells of the domestic fowl and the Japanese quail, and to the ovarian granulosa cells of the Japanese quail. The change we made from the original method consisted of (1) using chicken LH for radioiodination that was not only highly purified but also retained a high receptor binding potency; (2) controlling the level of incorporation of radioiodine into chicken LH molecules by employing a short reaction time and low temperature; and (3) fractionating radioiodinated chicken LH further by gel filtration using high-performance liquid chromatography. Specific radioactivity of the final {sup 125}I-labeled chicken LH preparation was 14 microCi/micrograms. When specific binding was 12-16%, nonspecific binding was as low as 2-4% in the ...
The recently described retinoid X receptors (RXRs) respond to the novel retinoid 9-cis-retinoic acid and also serve as heterodimeric partners for the vitamin D, thyroid hormone, and retinoic acid receptors (VDR, TR, and RAR, respectively). In this work, the authors report high-resolution localization of the human RXR genes within cytogenetic bands and also within a standard reference map of cosmid DNA markers on human chromosomes. They have determined the location of the human RXR genes by pairwise hybridization of the RXR cosmids and reference markers, using fluorescence in situ hybridization. They localized (i) RXR[alpha] (RXRA) to chromosome 9 band q34.3; (ii) RXR[beta] (RXRB) to chromosome 6 band 21.3; and (iii) RXR[gamma] (RXRG) to chromosome 1 band q22-q23. Six retinoid-responsive transcription factors have been identified so far, including three retinoic acid receptors in addition to the three RXRs. Interestingly, ...
Influence of alkali elements on formation, composition, solubility and region of stability of complex hafnium sulfates, separated in the HfO"2-H"2SO"4-Me"2SO"4-H"2O (Me-Na, K, Rb, Cs and NH"4 group) systems is studied. In all cases hafnium forms the complex sulfates of three types differing by basicity or ratio HfO"2:SO"3 1:1, 1:1.5, 1:2. Three basic and three medium sulfates are crystallized in the systems with sodium; with rubidium, cesium and ammonium - two basic and two medium sulfates and with potassium - two basic and one medium salts. Anhydrous salts do not form in the investigated systems. Potassium salt approximately 0.3% according to HfO"2 is characterized by minimum solubility from the salts of 2HfOSO"4x(1-3)Me"2SO"4x(4-6)xH"2O while solubility of the same salts with rubidium, cesium and sodium increases from (0.25-1.0); (0.5-1.5) till (1.0-5)% ...
Thermo-reactive diffusion chromizing followed by pulsed plasma nitriding were carried out on AISI 52100 and 8620 bearing steels. The chromized samples were pulse-plasma nitrided for 5 h at 500 deg. C in various N_2-H_2 gas mixtures. The coated steels were characterized using scanning electron microscopy, X-ray diffraction and microhardness testing. The unlubricated wear behaviors of only chromized and duplex treated steels were investigated in ball-on-disc system tests at room temperature. X-ray diffraction patterns of the duplex treated samples containing H_2 indicated the formation of dominant CrN and Cr_2N nitrides as well as the formation of Cr_3C_2 and Cr_7C_3 carbides. Gas mixtures in the plasma nitriding, which was performed after chromizing, have a significant influence on the wear rate of the duplex treated steels. The wear and friction tests showed that the lowest friction coefficient and wear ...
Chemical looping combustion (CLC) of simulated coal-derived synthesis gas was conducted with NiO oxygen carriers supported on SiO2, ZrO2, TiO2, and sepiolite. The effect of H2S on the performance of these samples for the CLC process was also evaluated. Five-cycle thermogravimetric analysis (TGA) tests at 800 C indicated that all oxygen carriers had a stable performance at 800 C, except NiO/SiO2. Full reduction/oxidation reactions of the oxygen carrier were obtained during the five-cycle test. It was found that support had a significant effect on reaction performance of NiO both in reduction and oxidation rates. The reduction reaction was significantly faster than the oxidation reaction for all oxygen carriers, while the oxidation reaction is fairly slow due to oxygen diffusion on NiO layers. The reaction profile was greatly affected by the presence of H2S, but there was no effect on the capacity due to ...
We investigate the relationship between spiral arms and star formation in the grand-design spirals NGC 5194 and NGC 628 and in the flocculent spiral NGC 6946. Filtered maps of near-IR (3.6 #mu#m) emission allow us to identify 'arm regions' that should correspond to regions of stellar mass density enhancements. The two grand-design spirals show a clear two-armed structure, while NGC 6946 is more complex. We examine these arm and interarm regions, looking at maps that trace recent star formation-far-ultraviolet (GALEX NGS) and 24 #mu#m emission (Spitzer SINGS)-and cold gas-CO (HERACLES) and H I (THINGS). We find the star formation tracers and CO more concentrated in the spiral arms than the stellar 3.6 #mu#m flux. If we define the spiral arms as the 25% highest pixels in the filtered 3.6 #mu#m images, we find that the majority (60%) of star formation tracers occur in the interarm regions; this result persists qualitatively even when considering the potential impact of finite data ...
The plerocercoid stage of the tapeworm Spirometra mansonoides produces a functional analog of human growth hormone (hGH). Among the similarities between plerocercoid growth factor (PGF) and hGH is competition for the same receptors on rabbit liver membranes. To take advantage of this characteristic in a purification scheme for PGF, rabbit liver microsomes were solubilized in Triton X-100 and the hGH receptors were purified over an hGH affinity column. The purified receptors from six rabbit livers were coupled to Affi-Gel-10 to create a receptor affinity column which was used to purify PGF. Chromatography of crude PGF over the receptor column resulted in a 1044 fold increase in specific activity. SDS-PAGE in the presence of 2-mercaptoethanol showed that the affinity-purified PGF contained three protein bands with apparent Mrs of 27.5 K, 22 K, and 16.7 K. Injections of the ...
(3H)Quinuclidinyl benzilate binding to rat brain muscarinic receptors decreased after repeated exposure to soman, a potent organophosphorus cholinesterase inhibitor. The topographical distribution of this decrement was analyzed by quantitative receptor autoradiography. After 4 weeks of soman, three times a week, quinuclidinyl benzilate binding decreased to 67 to 80% of control in frontal and parietal cortex, caudate-putamen, lateral septum, hippocampal body, dentate gyrus, superior colliculus, nucleus of the fifth nerve, and central grey. Minor or no decreases were observed in thalamic or hypothalamic nuclei, reticular formation, pontine nuclei, inferior colliculus, nucleus of the seventh nerve, and cerebellum. Scatchard analyses of saturation curves using frontal cortex sections from soman-treated rats revealed a decrease in maximal quinuclidinyl benzilate binding from that in control rats and a return toward control levels by 24 days without ...
[3H]Quinuclidinyl benzilate binding to rat brain muscarinic receptors decreased after repeated exposure to soman, a potent organophosphorus cholinesterase inhibitor. The topographical distribution of this decrement was analyzed by quantitative receptor autoradiography. After 4 weeks of soman, three times a week, quinuclidinyl benzilate binding decreased to 67 to 80% of control in frontal and parietal cortex, caudate-putamen, lateral septum, hippocampal body, dentate gyrus, superior colliculus, nucleus of the fifth nerve, and central grey. Minor or no decreases were observed in thalamic or hypothalamic nuclei, reticular formation, pontine nuclei, inferior colliculus, nucleus of the seventh nerve, and cerebellum. Scatchard analyses of saturation curves using frontal cortex sections from soman-treated rats revealed a decrease in maximal quinuclidinyl benzilate binding from that in control rats and a return toward control levels by 24 days without ...
Four major natriuretic peptides have been isolated: atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), C-type natriuretic peptide (CNP), and Dendroaspis-type natriuretic peptide (DNP). Natriuretic peptides play an important role in the regulation of cardiovascular homeostasis maintaining blood pressure and extracellular fluid volume. The classical endocrine effects of natriuretic peptides to modulate fluid and electrolyte balance and vascular smooth muscle tone are complemented by autocrine and paracrine actions that include regulation of coronary blood flow and, therefore, myocardial perfusion; modulation of proliferative responses during myocardial and vascular remodeling; and cytoprotective anti-ischemic effects. The actions of natriuretic peptides are mediated by the specific binding of these peptides to three cell surface receptors: type A natriuretic peptide receptor (NPR-A), type B natriuretic peptide ...
Aminophenpyramine, a derivative of mepyramine (pyrilamine), a typical antagonists of histamine at its H_1 receptor was synthesized and converted into ["1"2"5I]iodoazidophenpyramine, a potential photoaffinity probe for the H_1 receptor. In the dark, reversible binding of this probe to cerebellar membranes occurred with a K/sub d/ of 1.2 x 10"-"1"1 M and a B/sub max/ of 240 fmol/mg of protein and was inhibited by various H_1-receptor antagonists with the expected potencies. These features establish the compound as one of the most potent H_1-receptor antagonists known so far. Upon IV irradiation, 5% of the bound radioactivity was covalently incorporated into cerebellar membrane polypeptides as shown by standard NaDodSO_4/PAGE. Two bands of 47 and 56 kDa were consistently labeled, labeling being prevented by various H_1-receptor antagonists with the expected potencies and ...
A discussion is given concerning the transformation in acid medium of curite into copper-, nickel- and cobalt-uranylphosphate. From chemical, differentiel thermal and thermogravimetric analyses, the crystal-chemical formula are calculated as: Cu(UO_2/PO_4)_2.8H_2O, Ni(UO_2/PO_4)_2.7H_2O and Co(UO_2/PO_4)_2.7H_2O. The two last compounds crystallize in the triclinic system with space group P1 or P1(overscore) and the first one crystallizes in the tetragonal system with space group P4/nmm. The cell parameters are calculated. From solubility data, the solubility products are computed as 10sup(-12.8), 10sup(-9.5) and 10sup(-9.9) for the copper-, nickel- and colbalt-compound respectively. The electrokinetic properties of the three species are closely similar to those of natural meta-torbernite: the zeta-potential is negative and the point of zero charge be reached ...
Vanadium(V) in aqueous HCl, HNO_3 or H_2SO_4 solutions is extracted with 2-carbethoxy-5-hydroxy-1-(4-tolyl)-4-pyridone (HA) dissolved in CHCl_3 and determined spectrophotometrically, Depending on the composition of the aqueous phase, two complexes are formed. At pH 1 (HCl, HNO_3, H_2SO_4) VO_2A(HA)_2 is formed with maximal absorption at 478 nm. However, from 4-5 M HCl, VO_2Cl(HA)_3 is extracted, and has maximal absorption at 615 nm. The same complex is extracted from 2-3 M HNO_3 or 3-4 M H_2SO_4 if enough chloride is added. Solutions of both complexes follow Beer's law and the molar extinction coefficients are 4.15x10"3 1.mole"-"1cm"-"1 at 478 nm and 5.10x10"3 at 615 nm. The determination of vanadium at both wavelengths is very simple, fast and selective. The composition of the complexes was established by the usual methods as well as by characterization of the ...
Most palladium thin film based hydrogen gas sensors have response and recovery times that are too long to make them useful in vehicular and stationary gas leak detection applications. In contrast, a palladium-silver thin film based microcantilever (MC) hydrogen gas microsensor is reported herein with near ideal response characteristics for use in these hydrogen economy related applications. Specifically, 3-10 second response and recovery times have been measured for these sensors in contrast to previous sensor response measurements of several to tens of minutes using Pd thin film and MC based sensing techniques. The much reduced response times observed in the present study are attributed to a wet chemical Pd-Ag thin film deposition technique and a gas conditioning protocol that produces a highly nanostructured, porous film that rapidly adsorbs and desorbs H2, allowing rapid equilibration with the H2 ...
High general corrosion resistance of high-alloy OCTG (oil country tubular goods) to CO_2 may be limited by pitting corrosion in presence of chlorides and sulfides. The pitting resistance of 13% Cr steel, duplex and high Ni austenitic stainless steels have been examined by electrochemical measurements in a high temperature, high pressure autoclave simulating the well conditions. Each steel shows the pitting potential in CO_2-NaCl-H_2O system, the value of which being less noble as the Cl"- concentration and the temperature increase. The presence of H_2S is also detrimental. High alloying additions of Cr and Mo enhance pitting resistance whether or not H_2S is present. The corrosion potentials of these steels in the simulating well conditions in which oxygen is absent do not exceed the pitting potential. Therefore, pitting corrosion can not occur by the passivity ...
Previous work has shown the Orion Bar to be an interface between ionized and molecular gas, viewed roughly edge on, which is excited by the light from the Trapezium cluster. Much of the emission from any star-forming region will originate from such interfaces, so the Bar serves as a foundation test of any emission model. Here we combine X-ray, optical, IR and radio data sets to derive emission spectra along the transition from H+ to H0 to H2 regions. We then reproduce the spectra of these layers with a simulation that simultaneously accounts for the detailed microphysics of the gas, the grains, and molecules, especially H2 and CO. The magnetic field, observed to be the dominant pressure in another region of the Orion Nebula, is treated as a free parameter, along with the density of cosmic rays. Our model successfully accounts for the optical, IR and radio observations across the Bar by including a ...
Single crystal tungsten oxide (WO3) nanoparticles were prepared via a microwave-assisted method. Electrochemical activity for hydrogen evolution reaction (HER) on WO3 supported on carbon black (WO3/C) electrocatalyst was first studied in acid solution (0.5 M H2SO4) and alkaline solution (1.0 M KOH) at room temperature. The overall experimental results revealed that the electrocatalytic activity for HER on WO3/C is one order magnitude higher than those obtained with carbon black in 0.5 M H2SO4 and is six times than in the case of carbon black in 1.0 M KOH. These results demonstrated that WO3 could enhance the electrocatalytic activity for hydrogen evolution reaction in acid solution (0.5 M H2SO4) and alkaline solution (1.0 M KOH). On the other hand, the kinetic reaction mechanisms were disc...
We present results of near--IR long-slit spectroscopy in the J and K bands of the Seyfert 2 galaxies NGC 2110 and Circinus, investigating the gaseous distribution, excitation, reddening and kinematics. In NGC 2110, the emission line ratio [FeII]/Pa beta increases towards the nucleus (to ~ 7). The nuclear [Fe II]1.257 (microns) and Pa beta lines are broader (FWHM ~ 500 km/s) than the H2 (2.121) line (FWHM ~ 300 km/s). Both these results suggest that shocks, driven by the radio jet, are an important source of excitation of [Fe II]. The H2 excitation appears to be dominated by X-rays from the nucleus. In Circinus, both [FeII]/Pa beta and H2/Br gamma decrease from ~ 2 at 4 arcsec from the nucleus to nuclear values of ~ 0.6 and ~ 1, respectively, suggesting that the starburst dominates the nuclear excitation, while the AGN dominates the excitation further out (r > ...
The symmetric noncoplanar (e,2e) cross sections (momentum profiles) of H_2 and D_2 for the transitions to the 2p#sigma#_u and 2s#sigma#_g excited ion states have been measured, relative to the ground-state ion transition, using a high-sensitivity multichannel momentum-dispersive electron momentum spectrometer (EMS) at an impact energy of 1200 eV. Newly calculated plane-wave impulse approximation (PWIA) cross sections, based on a full-configuration-interaction H_2 wave function, are compared to the experimental results. These calculations are in better agreement with the experimental results for the transition to the 2s#sigma#_g ion state than the earlier theoretical work of Liu and Smith, Jr. [Phys. Rev. A 31, 3003 (1985)] which has been found to be in error. Nevertheless, significant discrepancies between the relative experimental and theoretical cross sections are observed for the transitions to ...
We study the evolution of the cold gas content of galaxies by splitting the interstellar medium into its atomic and molecular hydrogen components, using the galaxy formation model GALFORM in the LCDM framework. We calculate the molecular-to-atomic hydrogen mass ratio, H2/HI, in each galaxy using two different approaches; the pressure-based empirical relation of Blitz & Rosolowsky and the theoretical model of Krumholz, McKeee & Tumlinson, and apply them to consistently calculate the star formation rates of galaxies. We find that the model based on the Blitz & Rosolowsky law predicts an HI mass function, CO(1-0) luminosity function, correlations between the H2/HI ratio and stellar and cold gas mass, and infrared-CO luminosity relation in good agreement with local and high redshift observations. The HI mass function evolves weakly with redshift, with the number density of high mass galaxies ...
Two plasma chemistries, i.e., CH_4/H_2/Ar and Cl_2/Ar, were compared for the etching of InGaP, AlInP, and AlGaP under inductively coupled plasma (ICP) conditions. While the etching with CH_4/H_2/Ar discharges appears to be ion driven, Cl_2/Ar discharges showed an additional strong chemical enhancement. The highest etch rate (#approx#1 #mu#m/min) for InGaP was achieved at high ICP source power (#>=#750 W) with the Cl_2/Ar chemistry. Cl_2/Ar discharges provided very smooth surfaces in all three materials with root-mean-square roughness measured by atomic force microscopy around 2 nm. This result may be due to the efficient ion-assisted product desorption in this chemistry. The etched near-surface region of InGaP (#approx#100 Angstrom) with Cl_2/Ar maintained almost the same stoichiometry as that of the unetched control. By contrast, the CH_4/H_2/Ar plasma ...
A magnetic core/shell Fe3O4/FeMnOx catalyst was prepared by a simple oxidation-precipitation method. The catalyst was characterized by X-ray diffraction, transmission electron microscope, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis and cyclic voltammetry. The characterization studies verified that Fe3O4 core was coated with a layer of Fe-Mn oxide. The Fe3O4/FeMnOx was found to be an effective and stable heterogeneous catalyst for the discoloration of methylene blue (MB) in aqueous solution by H2O2. The high catalytic activity is due to the FeMnOx shell, which not only increased the surface hydroxyl groups, but also enhanced the interfacial electron transfer. The discoloration of MB could be due to the decomposition of H2O2 into ?OH ...
The work scope of 'Biological Research for the Radiation Protection' had contained the research about ornithine decarboxylase and its controlling proteins, thioredoxin, peroxiredoxin, S-adenosymethionine decarboxylase, and glutamate decarboxylase 67KD effect on the cell death triggered ionizing radiation and H_2O_2(toxic agents). In this study, to elucidate the role of these proteins in the ionizing radiation (or H_2O_2)-induced apoptotic cell death, we utilized sensesed (or antisensed) cells, which overexpress (or down-regulate) RNAs associated with these proteins biosynthesis, and investigated the effects of these genes on the cytotoxicity caused by ionizing radiation and H_2O_2(or paraquat). We also investigated whether genisteine(or thiamine) may enhance the cytotoxic efficacy of tumor cells caused by ionizing radiation (may enhance the preventing effect ...
One of the methods to protect a carbon steel material from corrosion attack of sulfuric acid environment is with anodic protection. This research was intended to investigate the effect of anodic protection quickened with potential polarization, The material under investigation were ASTM A 516 and JIS G 3131-SPHC in highly concentrated H_2SO_4 solution. The results showed that potential that was effective for anodic protection in ASTM A 516-60 were at 236-436 mV for 75%, 276-476 mV for 80%, 264-514 mV for 85%,285-485 mV for 90%, and 231-431 mV for 97% H_2SO_4 so that in JlS G 3131-SPHC were at 303 -503 mV for 75%, 290-490 mV for 80%, 269- 516 mV for 85%, 264-514 mV for 90%, and 287 -487 mV for 97% H_2SO_4.
This paper reports measurements of absolute differential cross sections for the direct scattering of oxygen atoms by He, Ne, Ar, Kr, Xe, H_2, N_2, O_2, CO, CO_2, H_2O, SO_2, NH_3, CH_4, CF_4, and SF_6 targets. The measured cross sections include contributions from all elastic and inelastic processes that result in a fast neutral oxygen atom product. Cross sections are presented for 0.5- and 1.5-keV projectile energies over the laboratory angular range 0.2 degree endash 5 degree. When compared in the center-of-mass reference frame, these cross sections exhibit a high degree of similarity in both amplitude and angular dependence. The cross sections for N_2, CO, CO_2, and H_2O are inverted using a partial-wave analysis to yield empirical interaction potentials, which can then be used to extrapolate the measurements down to lower energies. Using these potentials, ...
Background: Thyroid-stimulating autoantibodies (TSAb) bind to the thyrotropin receptor (TSHR) extracellular domain, or ectodomain (ECD), comprising a leucine-rich repeat domain (LRD) linked by a hinge region to the transmembrane domain (TMD). The LRD (residues 22???260; signal peptide 1???21) contains two disulfide-bonded loops at its N-terminus. In the crystal structure of the isolated LRD complexed with human TSAb monoclonal antibody (mAb) M22, N-terminal disulfide loop 1 (residues 22???30) could not be determined because of crystal disorder. Nevertheless, present crystal structure data are interpreted to exclude a role for the LRD N-terminal disulfide loops in the TSAb epitope(s), contradicting prior functional evidence of a role for these loops in TSAb function. Materials and Methods: ...
Somatostatin receptor scintigraphy (SRS) is a valuable method for the detection of somatostatin receptor-positive lesions. Most gastrinomas (over-)express the somatostatin receptor subtype 2 which can be targeted by In-111 labeled Octreotide. Different studies show a high sensitivity of SRS for the localization and staging of gastrinomas. SRS seems to be superior to other non-invasive imaging modalities and has been proven to significantly contribute to patient management. However, the sensitivity depends on the size and exact localization of the tumors. Smaller lesions and lesions located in the duodenum show a significantly lower sensitivity. In any case, SRS belongs to the routine imaging procedure for gastrinomas for localization and staging and can also be used for evaluation of the tumor progression. (author)
Keratinocyte growth factor receptor (KGFR) and fibroblast growth factor receptor (FGFR) 2c share identical amino acid sequences, except for a 46-amino acid domain in the extracellular region. Monoclonal antibodies (MAbs) specific to KGFR have not been reported nor are commercially available. In this study, we generated murine MAbs specific to KGFR in non-obese diabetic (NOD) mice using a modified Repeated Immunizations at Multiple Sites (RIMMS) technology. Stable cell lines expressing the full-length human KGFR or FGFR2c were produced to facilitate the identification of KGFR-specific MAbs. Following the initial screening of hybridoma clones with a fluorescence-based, confocal cell detection method and ELISA, KGFR-specific MAbs were selected and confirmed by flow cytometry and Western blot ...
Using the complex Kohn method, we have calculated variational values of phase shifts and the annihilation parameter, Z_{eff}, for the elastic scattering of positrons by molecular hydrogen. Our results are sensitive to small changes in the accuracy of the wave function representing the target hydrogen molecule. We have developed a systematic approach to demonstrate that, at low positron energies, there are particular forms of the Kohn trial wave function for which the results of variational calculations are not reliable, even when the target wave function accounts for as much as 96.8% of the correlation energy of H_{2}. We find that reliable results can be recovered if our calculations are extended to admit more sophisticated target wave functions accounting for 99.7% of the correlation energy. Remaining discrepancies between theory and experiment are briefly discussed.
It was demonstrated that R 2?R 4 saturated monohydric alcohols can be synthesized from CO and H2 in the presence of Fe catalysts containing a carbon support of the Sibunit type with granule sizes of 3?5, 1?2, and 0.05?0.1 mm in a fixed-bed reactor at 3 MPa and 240?300?C. It was found that the activity of Fe/Sibunit catalysts and their selectivity for the formation of liquid synthetic products increased with the size of granules and the amount of iron. The catalysts make it possible to obtain fatty alcohols, in which the fraction of R 2?R 4 alcohols is as high as 75%, in yields to 56 g/m3.
Corrosion inhibition of iron in H2SO4 by polyacrylic acid (PAA) was investigated using electrochemical techniques at 30degreeC. Results obtained indicate that PAA inhibited the corrosion of iron in the acid medium. Inhibition efficiency increases with increase in PAA concentration and synergistically enhanced on addition of iodide ions. Potentiodynamic polarization results suggest that PAA functions as a modest cathodic inhibitor. The adsorption of PAA onto the iron surface followed Temkin adsorption isotherm. FTIR analysis revealed that the synergistic effect due to co-adsorption of iodide ions and PAA is co-operative in nature.
A method for range-resolved gas sensing using path-integrated optical systems is presented. The method involves dividing an absorption path into several measurement segments and extracting the gas concentration in each segment from two path-integrated measurements. We implemented the method with tunable lasers (a 1389-nm VCSEL and a 10.9-?m pulsed quantum cascade laser) and a group of retro reflectors (RRs) distributed along absorption paths. Using a rotating mirror with the VCSEL configuration, we could scan a group of seven tape RRs spaced by 10?cm in ??9?ms to extract an H2O concentration profile. Reduced H2O concentrations were recorded in the segments purged with dry air. Hollow corner cube RRs were used in the quantum cascade laser configuration at distances up to 1.1?km from the las...
P-implantation (10"1"7 ions cm"-"2, 40 KeV) into 304 stainless steel (ss) has been carried out, and an amorphous surface alloy was formed. Polarization studies in deaerated 1N H_2SO_4+ 2% NaCl showed that P-implantation improved both the general and localized corrosion resistance of 304 ss. A comparative study has been carried out between the implanted and unimplanted steel to determine what influence P-implantation has upon the properties of the passive film formed 1N H_2SO_4. The influence of Cl ions on pre-formed passive films was also studied. RHEED, XPS and AES were used to evaluate the nature of the passive films formed in these studies.
The possibility has been studied of oxidizing Prsup((3)) to Prsup((4)) when Prsup((3)) is added to an aqueous weakly-acid solution containing K_1_0[P_2W_1_7O_6_1H_2O] x H_2O. A sharp change in the solution colouring has been observed as a result of Prsup((3)) oxidation to Prsup((4)). The absorption spectra of solution of Prsup((4)) have been recorded and the values of the molar extinction coefficients have been determined. On storage of the solution, Prsup((4))reduces to Prsup((3)) with a half-reduction period of 0.2-0.5 hour.
The optical emission of excited H reflected from clean Cu(110) after impingement of H"+ and H_2"+ in the energy range of 250 eV to 20 keV per nucleon at 70"0 angle of incidence to the surface normal was measured. For incident 10 keV H_2"+, the highest excited hydrogen state detected was the n=10 level. The Hsub(#alpha#) yield was found to be fluence and energy dependent. This effect is attributed either to fast sputtered hydrogen, surface roughness or to an increase with hydrogen concentration in electron states of p-like symmetry near the Fermi level of copper. The Hsub(#alpha#) yield per reflected nucleon shows approximately an exponential dependence on both projectile energy per nucleon and scattered particle reciprocal velocity perpendicular to the surface. (orig.).
A novel heteropolyanion-based ionic hybrid was prepared by combining the divalent ionic liquid (IL) cation of 1,1'-(butane-1,4-diyl)-bis(3-methylimidazolium) with the Keggin-structured V-containing heteropolyanion, and characterized by ^1H NMR, FT-IR, ESI-MS, XRD, SEM, TG, BET surface area, melting point, and elemental analysis. Its catalytic activity was evaluated in the hydroxylation of benzene with aqueous H2O2, including the testing of the influence of organic cations, catalytic reusability and optimization of reaction conditions. This hybrid is characterized to be semi-amorphous nanoparticles with a IL-like composition. The hybrid catalyst leads to the liquid-solid biphasic reaction system for hydroxylation of benzene with H2O2, presenting such advantages as high catalytic activity, c...
In a sufficiently large cluster of several polar molecules, collective interactions lead to localization or 'solvation' of electrons. The existence of the solvated electron is known since 1863 in liquid ammonia and since 1962 for liquid water. In 1984, electron localization in clusters was experimentally demonstrated in (H_2O)_N_#>=#_1_1 and (NH_3)_N_#>=#_3_4 clusters. In cooperation with K. Bowen, we recently initiated a test of the theory of electron binding by a dipole and a new ground state dipole bound dimer anion, (H_2O..NH_3), was predicted and observed. We here describe results of a search for new dipole-bound and solvated electron systems. (author).
In eukaryotes, accurate chromosome segregation during mitosis and meiosis is coordinated by kinetochores, which are unique chromosomal sites for microtubule attachment. Centromeres specify the kinetochore formation sites on individual chromosomes, and are epigenetically marked by the assembly of nucleosomes containing the centromere-specific histone H3 variant, CENP-A. Although the underlying mechanism is unclear, centromere inheritance is probably dictated by the architecture of the centromeric nucleosome. Here we report the crystal structure of the human centromeric nucleosome containing CENP-A and its cognate ?-satellite DNA derivative (147 base pairs). In the human CENP-A nucleosome, the DNA is wrapped around the histone octamer, consisting of two each of histones H2A, H2B, H4 and CENP...
Measurements of absolute differential cross sections for H"+-H_2 direct, single-, and double-charge-transfer scattering at 0.5, 1.5, and 5.0 keV are reported at laboratory scattering angles less than 1 degree with an angular resolution of approximately 0.02 degree. The cross sections exhibit deep interference oscillations in single-charge-transfer scattering, but no such oscillations are present in direct and double-charge-transfer scattering. Theoretical cross sections derived using the diatoms-in-molecules method to describe the molecular states in a semiclassical molecular-orbital three-state close-coupling model within a semiclassical framework agree satisfactorily with the experimental results.
In this article a methodology is presented for studying the influence of the biomass moisture content and the biomass/air ratio on the producer gas composition and on the chemiluminescent emissions during the combustion process. Firstly, a mathematical model based on the thermo-chemical processes inside the gasifier is used to predict the composition of the producer gas as a mixture of CO, CO2, H2, N2, CH4 and H2O gases. Secondly, the predicted composition is introduced into a constant volume combustion bomb (CVCB), which simulates the typical conditions inside the combustion chamber of an internal combustion engine, in order to characterize its combustion under gasoline-type conditions through the instantaneous pressure and the detection of the spontaneous luminous radiation (chemilumines...
Potential of spent biomass of a cyanobacterium, Nostoc linckia HA 46, from a hydrogen bioreactor was studied for biosorption of a textile dye, reactive red 198. The waste biomass was immobilized in calcium alginate and used for biosorption of the dye from aqueous solution using response surface methodology (RSM). Kinetics of the dye in aqueous solution was studied in batch mode. Interactive effects of initial dye concentration (100-500mg/L), pH (2-6) and temperature (25-45^oC) on dye removal were examined using Box-Behnken design. Maximum adsorption capacity of the immobilized biomass was 93.5mg/g at pH2.0, initial concentration of 100mg/L and 35^oC temperature, when 94% of the dye was removed. Fourier transform infrared (FT-IR) studies revealed that biosorption was mainly mediated by fun...
A new strontium metal-organic framework, [Sr2(BTEC)(H2O)4] 2H2O (1) (H4BTEC=benzene-1,2,4,5-tetracarboxylic acid), has been successfully synthesized by mixing the starting reagents. The single-crystal structure analysis showed that compound 1 displayed three-dimensional structures containing inorganic motifs with two-dimensional layers pillar-connected through organic linkers and forming water-coordinated neutral framework. Further studies revealed that compound 1 was insoluble in water and that it emitted strong luminescence at approximately 437nm after dehydration.
Hydrogen (H) plasma treatment, oxygen (O) plasma treatment and water (H_2O)-vapor heat treatment for polycrystalline-silicon (poly-Si) thin-film transistors (TFTs) have been analyzed by separately extracting trap density at a front silicon-oxide interface (D_F) and trap density at a back interface (D_B). It is found that the H plasma treatment is apt to generate D_F and D_B. The O plasma treatment reduces D_F, while the H_2O-vapor heat treatment reduces both D_F and D_B. Improvement of transistor characteristics of poly-Si TFTs depends on understanding these results.
We propose a combined experimental (Atomic Force Microscopy) and theoretical study of the structural and dynamical properties of nucleosomes. In contrast to biochemical approaches, this method allows to determine simultaneously the DNA complexed length distribution and nucleosome position in various contexts. First, we show that differences in the nucleo-proteic structure observed between conventional H2A and H2A.Bbd variant nucleosomes induce quantitative changes in the in the length distribution of DNA complexed with histones. Then, the sliding action of remodeling complex SWI/SNF is characterized through the evolution of the nucleosome position and wrapped DNA length mapping. Using a linear energetic model for the distribution of DNA complexed length, we extract the net wrapping energy of DNA onto the histone octamer, and compare it to previous studies.
Austenitic stainless steel AISI 304 has been nitrided by radio frequency (rf) plasma containing various nitrogen-hydrogen gas mixtures, in order to study the effect of hydrogen on structure and magnetic properties of the formed compound layer. The thermal temperature has been measured at the vicinity of the samples. The compound layer thus produced has been characterized using, X-ray diffractometer and vibration sample magnetometer. Providing the total pressure of nitrogen and hydrogen is held constant, the addition of hydrogen up to 50% gives new structural phases. The magnetization values of the plasma treated samples are strongly dependent on the percentage of H_2 in the gas phase. An excessive amount of hydrogen (#approx#75%) on the other hand, retards the nitriding process. The surface temperature of the sample and plasma condition is crucial factors for nitriding process.
Abstract Surface modification of topography and chemistry in order to achieve a specific water contact angle (CA) has been explored by using a novel combinatorial screening platform. The screening arrays consisted of 507 distinct combinations of micro-topographies and chemical compositions. By performing chemical modifications with 1H, 1H, 2H, 2H perfluoroethyltriethoxy-silane (PFS) and n-octadecyltriethoxysilane (ODS) on standard silicon wafers it was possible to include both superhydrophobic and very hydrophilic pad arrays in the same screening platform. Surfaces modified with PFS were more hydrophobic than surfaces modified with ODS, while the unmodified silicon surfaces were hydrophilic. For the PFS modified surfaces the largest CAs were achieved with a small pillar size of X-=-1-m and...
The mechanisms that contribute to the extinction of previously acquired memories are not well understood. These processes, often referred to as inhibitory learning, are thought to be parallel...Full Text Available
Transient receptor potential (TRP) ion channels have been implicated in detecting chemical, thermal and mechanical stimuli in organisms ranging from mammals to Caenorhabditis elegans....Full Text Available
BackgroundGreen tea consumption has been shown to have cancer preventive qualities. Among the constituents of green tea, (-)-Epigallocatechin-3-O-gallate (EGCG)...Full Text Available
Receptor protein tyrosine phosphatase T (PTPRT/PTPρ) is frequently mutated in human cancers including colon, lung, gastric and skin cancers. More than half of the identified tumor-derived...Full Text Available
BackgroundThe dynorphin-kappa opioid receptor (KOR) system regulates glial proliferation after sciatic nerve injury. Here, we investigated its role in cell proliferation following...Full Text Available
Experience-dependent plastic changes in the central sensory systems are due to activation of both the sensory and neuromodulatory systems. Nonspecific changes of cortical auditory neurons elicited by...Full Text Available
Recent research has implicated the nucleus accumbens (NAc) in consolidating recently acquired goal-directed appetitive memories, including spatial learning and other instrumental processes. However,...Full Text Available
1. The stereospecificity of the enantiomers of LY253352, a potent and selective alpha 1-adrenoceptor antagonist, were studied in the human prostate and canine brain using radioligand receptor binding...Full Text Available
Cervical spinal cord hemisection rostral to the phrenic nucleus leads to paralysis of the ipsilateral hemidiaphragm in adult rats. Respiratory function can be restored to the paralyzed hemidiaphragm...Full Text Available
[3,5-"3H] 4-Azidoclonidine 6 was prepared from [3,5-"3H] 4-aminoclonidine 4 and has emerged as a valuable tool to study the alpha-2-adrenergic receptor. (author)
Studies in rodents have shown that male sexual function can be disrupted by fetal or neonatal administration of compounds that alter endocrine homeostasis, such as the synthetic nonsteroidal estrogen...Full Text Available
AimsIt is unclear as to which mediators are involved in mediating the response to nasal mannitol challenge, a novel osmotic stimulus.MethodsA...Full Text Available
BackgroundNFκB signaling is of paramount importance in the regulation of apoptosis, proliferation, and inflammatory responses during human development and homeostasis, as...Full Text Available
The C-C chemokine receptor 5, 32 base-pair deletion (CCR5-Δ32) allele confers strong resistance to infection by the AIDS virus HIV. Previous studies have suggested...Full Text Available
SummaryTRPV1 is the founding and best-studied member of the family of temperature-activated transient receptor potential ion channels (thermoTRPs). Voltage, chemicals, and heat...Full Text Available
Peptide toxins with high affinity, divergent pharmacological functions, and isoform-specific selectivity are powerful tools for investigating the structure-function relationships of voltage-gated...Full Text Available
The synthesis and structure-activity relationship analysis of a novel class of amide-based biaryl NR2B-selective NMDA receptor antagonists are presented. Some of the studied compounds are potent, selective, non-competitive, and voltage-independent antagonists of NR2B-containing NMDA receptors. Like the founding member of this class of antagonists (ifenprodil), several interesting compounds of the series bind to the amino terminal domain of the NR2B subunit to inhibit function. Analogue potency is modulated by linker length, flexibility, and hydrogen bonding opportunities. However, unlike previously described classes of NR2B-selective NMDA antagonists that exhibit off-target activity at a variety of monoamine receptors, the compounds described herein show much diminished effects against the...
Understanding the mechanisms whereby information encoded within patterns of action potentials is deciphered by neurons is central to cognitive psychology. The multiprotein complexes formed by...Full Text Available
Gonadal, adrenal, and thyroid hormones affect the brain directly, and the sensitivity to hormones begins in embryonic life with the appearance of hormone receptor sites in discrete populations of neurons....Full Text Available
Somatostatin receptor expression has been demonstrated on a number of plasma cell lines. Therefore, we questioned whether somatostatin receptor scintigraphy (SRS) can be used to demonstrate in vivo multiple myeloma (MM) activity. SRS was performed in newly diagnosed (n = 9) or relapsing (n = 18) MM patients or in patients with localized plasmacytoma (n = 2). The results were compared with radiographic findings. A positive SRS was demonstrated in 44% of the newly diagnosed patients, in 83% of the relapsed patients and in both patients with plasmacytoma. The SRS findings corresponded with radiographic abnormalities in 40% of the patients. However, in relapsed patients 60% demonstrated increased SRS uptake in areas without new radiographic abnormalities. The positive SRS corresponded with histologically proven disease activity and responded upon treatment. Moreover, immunohistochemical staining of MM material demonstrated concordant somatostatin ...
Receptor activator of NF-kB ligand (RANKL) and osteoprotegerin (OPG) play key roles in the pathogenesis of glucocorticoid-induced osteoporosis (GIO). The aim of our study was to determine whether the...Full Text Available
Human epidermal growth factor receptor 2 (HER2) is one of the most important prognostic and predictive factors for breast cancer patients. Recently, serum HER2...Full Text Available
The goal of ultrasonic molecular imaging is the detection of targeted contrast agents bound to receptors on endothelial cells. We propose imaging methods that can distinguish adherent microbubbles...Full Text Available
Background:Endothelin-1 may be involved in the development of diabetic microangiopathy. We studied the effect of endothelin-1 blockade on myocardial microcirculation during coronary...Full Text Available
Rejection of eight aldehydes, eight ketones, five secondary alcohols, and 3-pentanol has been studied in the blowfly Phormia regina Meigen. The data agree with results previously reported...Full Text Available
The effect of A1-adenosine receptor antagonism via 8-cyclopentyl-1,3-dipropyl-xanthine (CPDPX) on the stimulation of skeletal muscle glucose uptake by...Full Text Available
PurposeIn our previous studies we showed that upregulating claudin-6 (CLDN6) expression may contribute to preventing breast cancer, and that 17β-estradiol induces a concentration-...Full Text Available
A statistical method is developed to determine the locations of major pollutant sources affecting a distant downwind receptor, provided that air trajectories can be estimated. Probability density functions are estimated which indicate the overall residence time of air parcels over a given geographic region as they travel toward a receptor and residence time for the case of high pollutant concentrations at the receptor. These functions are used to estimate a conditional probability function which indicates the potential for a source region to contribute to high air pollution concentrations. Finally, a source contribution function is formulated to indicate the relative contribution of different source regions to high concentrations at the receptor. The method is tested using data collected at Grand Canyon National Park in 1980. The dominant pathway for air masses arriving at Grand Canyon during this ...
In this study we compared the molecular signalling elicited by rexinoids, selective retinoid X receptor (RXR)-activators, in several organs (i.e. liver, kidney,...Full Text Available
BackgroundGlucocorticoids down-regulate cytokine synthesis and suppress inflammatory responses. The glucocorticoid receptor (GR) antagonist RU486 may exacerbate the inflammatory...Full Text Available
Breast cancer is a progressive and potentially fatal disease that affects women of all ages. Like all progressive diseases, early and reliable diagnosis is the key for successful treatment and annihilation....Full Text Available
BackgroundThe lactogenic hormones prolactin (PRL) and placental lactogens (PL) play central roles in reproduction and mammary development. Their actions are mediated via binding...Full Text Available
Cervical cancer is known to metastasize primarily by the lymphatic system. Dissemination through lymphatic vessels represents an early step in regional tumor progression, and the presence of lymphatic...Full Text Available
Hypoxia, or reduced oxygen, occurs in a variety of clinical and environmental situations. Hypoxic exposure is associated with decreased muscle mass and a concomitant reduction in exercise capacity,...Full Text Available
Prenatal cocaine exposure produces sustained neurobehavioral and brain synaptic changes closely resembling those of animals with defective alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic...Full Text Available
Cleavage of membrane-associated proteins with the release of biologically active macromolecules is an emerging theme in biology. However, little is known about the nature and regulation of the involved...Full Text Available
Although the mechanism is unknown, Calculus Bovis and its active components, cholic acid analogs (CAAs), have been used in China to treat a wide range of diseases. Based on the previous finding that the potency of CAA is strongly dependent on the intrinsic surface activity, this paper aimed to investigate the role of the plasma membrane in the pharmacological activity of CAAs. First, CAAs (0.1 mM) caused a surface activity-dependent depression on ATPase activity in the cell membrane extract, but it had no effects on other cellular extracts, suggesting an indispensable role of the membrane environment for pharmacological activity. Second, CAAs lowered the membrane fluidity of cultured Caco-2 cells with the same rank-order of potency sequence. Third, the hypothesis that any functional protein located on the membrane is influenced by changes in cellular membrane fluidity was supported by: ileal contraction that was induced by acetylcholine and mediated by the muscarinic ...
BackgroundZibotentan (ZD4054) is a specific endothelin A (ETA) receptor antagonist being investigated for the treatment of prostate cancer. As zibotentan is eliminated...Full Text Available
A parallel bundle of transmembrane (TM) alpha-helices surrounding a central pore is present in several classes of ion channel, including the nicotinic acetylcholine receptor (nAChR). We have modeled...Full Text Available
Idiopathic pulmonary fibrosis (IPF) is a progressive disease with poor survival. The identification of therapeutic targets is essential to improving outcomes. Previous studies found that expression...Full Text Available
Acute inflammation is important for tissue repair; however, chronic inflammation contributes to neurodegeneration in Alzheimer’s disease (AD) and occurs when glial cells undergo prolonged...Full Text Available
IntroductionIn the last few years, various studies have underlined a correlation between thyroid function and male sexual function, hypothesizing a direct action of thyroid hormones...Full Text Available
Macrophage activation by the proinflammatory cytokine interferon-γ (IFN-γ) is a critical component of the host innate response to bacterial pathogenesis. However, the precise nature...Full Text Available
The majority of diseases in the retina are caused by genetic mutations affecting the development and function of photoreceptor cells. The transcriptional networks directing these processes are regulated...Full Text Available
Nicotine is the main psychoactive ingredient in tobacco and its rewarding effects are considered primarily responsible for persistent tobacco smoking and relapse. Although dopamine has been extensively...Full Text Available
Women experience a decline in estrogen and androgen levels after natural or surgically induced menopause, effects that are associated with a loss of sexual desire and bone mineral density. Studies in...Full Text Available
The CNS can exhibit features of inflammation in response to injury, infection or disease, whereby resident cells generate inflammatory mediators, including cytokines, prostaglandins, free radicals and...Full Text Available
Hypoxia–ischemia (H/I) in the premature infant leads to white matter injury termed periventricular leukomalacia (PVL), the leading cause of subsequent neurological deficits. Glutamatergic...Full Text Available
Myelin-associated glycoprotein (MAG) has been implicated in inhibition of nerve regeneration in the CNS. This results from interactions between MAG and the Nogo receptor and gangliosides on...Full Text Available
The X-ray crystallographic structural determinations of synthetic estrogens and antiestrogens provide reliable information on the global minimum energy conformation of these molecules or a local minimum...Full Text Available
Cytoadherence or sequestration is essential for the pathogenesis of the most virulent human malaria species, Plasmodium falciparum (P. falciparum). Similar to leukocyte-endothelium...Full Text Available
Human skin is a local source of corticotropin-releasing hormone (CRH) and expresses CRH and CRH receptors (CRH-R) at mRNA and protein levels. Epidermal melanocytes respond to CRH by induction...Full Text Available
Antibodies to myelin oligodendrocyte glycoprotein (MOG) have been implicated in Multiple Sclerosis demyelination through activation of complement and/or macrophage-effector processes. We presented...Full Text Available
We had previously identified a macrophage surface protein whose expression is highly induced, transient, and specific, as it is restricted to actively fusing macrophages in vitro and in vivo. This protein...Full Text Available
A growing number of studies suggest that the development of compulsive drug seeking and taking depends on dorsostriatal mechanisms. We previously observed that ex vivo acute...Full Text Available
In addition to its role in megakaryocyte production, signaling initiated by thrombopoietin (TPO) activation of its receptor, myeloproliferative leukemia virus protooncogene (c-Mpl, or Mpl), controls...Full Text Available
Host cells use metabolic signaling through the LXRα nuclear receptor to defend against Listeria monocytogenes infection. 25-Hydroxycholesterol is a natural ligand of LXRs that...Full Text Available
Disruption of circadian rhythms may be involved in the pathophysiology of psychiatric disorders, including drug addiction. Recently, we detected the significant association between prokineticin 2 receptor...Full Text Available
Hematopoiesis is the cumulative result of intricately regulated signaling pathways that are mediated by cytokines and their receptors. Studies conducted over the past 10 to 15 years have revealed that...Full Text Available
The agglutination of human platelets by ristocetin and von Willebrand factor was inhibited by aggregated immunoglobulin (Ig)G and by Fc fragments of IgG, but not by Fab, F(ab′)2 or...Full Text Available
BackgroundThe VP2 outer capsid protein Bluetongue Virus (BTV) is responsible for receptor binding, haemagglutination and eliciting host-specific immunity. However, the assembly of...Full Text Available
Sensory experience plays a crucial role in regulating neuronal shape and in developing synaptic contacts during brain formation. These features are required for a neuron to receive, integrate, and transmit...Full Text Available
Hyperproliferation of the colonic epithelium, leading to expansion of colonic crypt progenitors, is a recognized risk factor for colorectal cancer. Overexpression of progastrin, a nonamidated and incompletely...Full Text Available
The endothelin-B (ETB) receptor is a G-protein-coupled receptor that binds endothelin ligands and is essential for the development of epidermal melanocytes and enteric neurons. Recent reports indicate that ETB is localized to nuclei in cardiac ventricular myocytes, although it has been thought that ETB is localized mainly on the plasma membrane. It remains unknown, however, whether this unique distribution of ETB occurs in other tissues. To elucidate the subcellular distribution of ETB in the intestine, we performed immunofluorescence of ETB in mouse intestine using a specific antibody. ETB-like immunoreactivity was detected in both the mucosal and muscle layers. In the mucosal layer, villous epithelial cells, stromal cells of the lamina propria, and cryptic cells were immunostained. Subcellularly, ETB is localized mainly to the nuclei of villous epithelial cells. In the muscle layer, immunoreactivity of ETB was localized to the myenteric ...
Neuropilin-1 (NRP1) acts as a co-receptor for class 3 semaphorins and vascular endothelial growth factor and is an attractive angiogenesis target for cancer therapy. In addition to the transmembrane...Full Text Available
Bacillus thuringiensis subsp. israelensis, which is used worldwide to control Aedes aegypti larvae, produces Cry11Aa and other toxins during...Full Text Available
Histamine has been proposed to be an important regulator of energy intake and expenditure. The aim of this study was to evaluate histamine regulation of glucose and lipid metabolism and development...Full Text Available
Recently, we demonstrated that the central ghrelin signalling system, involving the ghrelin receptor (GHS-R1A), is important for alcohol reinforcement. Ghrelin targets a key mesolimbic circuit involved...Full Text Available
Place fields of hippocampal pyramidal cells expand asymmetrically when adult rats repeatedly follow the same route. This behaviorally-induced expression of neuronal plasticity utilizes an NMDAR-dependent,...Full Text Available
The genetic basis of odorant-specific variations in human olfactory thresholds, and in particular of enhanced odorant sensitivity (hyperosmia), remains largely unknown. Olfactory receptor (OR) segregating...Full Text Available
The role of pheromone biosynthesis activating neuropeptide (PBAN) in the regulation of pheromone biosynthesis of several female moth species is well elucidated, but its role in the males has been a...Full Text Available
Exteriorized phosphatidylserine (PS) residues in apoptotic cells trigger rapid phagocytosis by macrophage scavenger receptor pathways. Mimicking apoptosis with liposomes containing PS may represent...Full Text Available
Dectin-1, the major β-glucan receptor in leukocytes, triggers an effective immune response upon fungal recognition. Here we use sortase-mediated transpeptidation, a technique that allows placement...Full Text Available
Tamoxifen (TAM) is a selective estrogen receptor modulator widely used in the prevention and treatment of breast cancer. A major mode of metabolism of the major active metabolites of TAM, 4-OH-TAM...Full Text Available
Fibroblast growth factor (FGF) signaling is involved in skeletal development of the vertebrate. Gain-of-function mutations of FGF receptors (FGFR) cause craniosynostosis, premature fusion of the skull,...Full Text Available
BackgroundLeukotrienes (LTs) belong to the large family of lipid mediators implicated in various inflammatory conditions such as asthma and rheumatoid arthritis. Four distinct types...Full Text Available
SUMMARYMotile dendritic filopodial processes are thought to be precursors of spine synapses, but how motility relates to cell-surface cues required for axon-dendrite recognition...Full Text Available
Protective innate immunity to the nematode Strongyloides stercoralis requires eosinophils in the parasite killing process. Experiments were performed to determine if an extract of S....Full Text Available
BackgroundThiazolidinediones (TZDs) activate peroxisome proliferator-activated receptor gamma (PPARγ) and are used clinically to help restore peripheral insulin sensitivity...Full Text Available
Porphyromonas gingivalis has been implicated as a causative pathogen in periodontitis. Immunotherapeutic approaches have recently been suggested to aid in the clearance of P....Full Text Available
The specific receptor sites and the endocytosis of transferrin (Tf) are evidenced in a cell line (HT-29) derived from a human colic adenocarcinoma by means of "1"2"5I radiolabeled Tf. The receptor density is studied in undifferentiated (UD) or differentiated (D) cells with respective doubling times of about 24 hours and 46 hours. The number of binding sites for Tf is 162,000 (K_d = 7.8 nmol/l in ND cells and 68,000 (K_d = 7.40 nmol/l) in D cells. The distribution between the Tf bound to the cell surface and the internalized Tf is investigated by elimination of Tf bound to the surface by an acid wash method. The intracellular cycle of Tf seems to be characterized by a slower kinetics in UD cells. The high density of Tf receptor sites in HT-29 UD cells should allow the detection or the treatment of highly evolutive colic adenocarcinoma by means of Tf.
B lymphocytes can function independently as efficient APCs. However, our previous studies demonstrate that both dendritic cells and macrophages are necessary to propagate immune responses initiated...Full Text Available
Glioblastoma, the most common malignant brain tumor, is among the most lethal and difficult cancers to treat. Although epidermal growth factor receptor (EGFR) mutations are frequent in glioblastoma,...Full Text Available
BackgroundThe N-methyl-D-aspartate (NMDA)-type glutamate receptor expressed at excitatory glutamatergic synapses is required for learning and memory and is critical for normal brain...Full Text Available
Retinoic acid inducible gene I (RIG-I) is a pattern recognition receptor (PRR) responsible for detection of nucleic acids from pathogens in the cytoplasm of infected cells and induction of type I interferon...Full Text Available
SummaryHuman skin expresses elements of the hypothalamo-pituitary-adrenal (HPA) axis including pro-opiomelanocortin (POMC), corticotropin releasing hormone (CRH), the CRH receptor-1...Full Text Available
We investigated the effects of PSARK∷IPT (for Senescence-Associated Receptor Kinase∷Isopentenyltransferase) expression and cytokinin production...Full Text Available
Cyclophilins (Cyps), the intracellular receptors for Cyclosporine A (CsA), are responsible for peptidyl-prolyl cis-trans isomerisation and for chaperoning several membrane proteins. Those functions...Full Text Available
BackgroundMost rapidly evolving gene families are involved in immune responses and reproduction, two biological functions which have been assigned to the carcinoembryonic antigen...Full Text Available
Mechanisms regulating sexual differentiation of the zebra finch song system appear to include both genetic and hormonal factors. Sorting Nexin 2 (SNX2), which is involved in trafficking proteins...Full Text Available
We presented data showing that the CART-19 cells expressing the 4-1BB signaling domain can have unprecedented and massive in-vivo expansion, traffic to tumor sites, persist long term in vivo, and induce...Full Text Available
Cytokinins are distributed through the vascular system and trigger responses of target cells via receptor-mediated signal transduction. Perception and transduction of the signal can occur at the plasma...Full Text Available
Cd36 is a small-molecular-weight integral membrane protein expressed in a diverse, but select, range of cell types. It has an equally diverse range of ligands and physiological functions, which has...Full Text Available
Klebsiella pneumoniae is able to grow anaerobically with citrate as a sole carbon and energy source by a fermentative pathway involving the Na+-dependent citrate...Full Text Available
Benzodiazepine withdrawal anxiety is associated with potentiation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate receptor (AMPAR) currents in hippocampal CA1 pyramidal...Full Text Available
Calcium, vitamin D, exposure to sunshine, and vitamin D receptor (VDR) genotypes have been associated rectal cancer. We used data from 750 rectal tumors and 1,205 population-based...Full Text Available
Recent evidence suggests a role for corticotropin-releasing factor (CRF) in the regulation of pair bonding in prairie voles. We have previously shown that monogamous and non-monogamous vole...Full Text Available
The pharynx is the primary reservoir for strains of group A Streptococcus (GAS) associated both with pharyngitis (streptococcal sore throat) and with invasive or “flesh-eating”...Full Text Available
Bacterial pathogens use virulence strategies to invade epithelial barriers, but active processes of epithelial cells may also contribute to the endocytosis of microbial particles. To focus on the latter,...Full Text Available
AIM: To investigate atrial natriuretic peptide (ANP) secretion from gastric mucosa and the relationship between the ANP/natriuretic peptide receptor type A (NPR-A) pathway and diabetic gastroparesis.METHODS:...Full Text Available
Experimental studies have demonstrated that not only dopaminergic signaling but also glutamatergic/NMDA receptor signaling play indispensable roles in the development of methamphetamine psychosis. Our...Full Text Available
Pharmacologic or genetic deletion of components of the renin-angiotensin system leads to postnatal kidney injury, but the roles of these components in kidney development are unknown. To test the hypothesis...Full Text Available
Numerous xenobiotics, including therapeutics agents, are substrates for bioactivation to electrophilic reactive intermediates that may covalently modify biomolecules. Selective estrogen receptor...Full Text Available
BackgroundMale infertility is a common cause of reproductive failure in humans. In mice, targeted deletions of the genes coding for FKBP6 or FKBP52, members of the FK506 binding...Full Text Available
We sought to determine the effects of activation of peroxisome proliferator-activated receptor-γ (PPAR-γ) on multilocularization of adipocytes in adult white adipose tissue (WAT). Male...Full Text Available
Endogenous immune complexes present in sera from 10 different patients with systemic lupus erythematosus (SLE) in an active phase were allowed to bind to Raji cells; the ability of intact complement...Full Text Available
BackgroundCentrosome aberrations can cause genomic instability and correlate with malignant progression in common human malignancies such as breast and prostate cancer. Deregulation...Full Text Available
The ventromedial hypothalamus (VMH) plays a central role in the regulation of the female reproductive behavior lordosis, a behavior dependent upon the sequential activation of receptors for the ovarian...Full Text Available
ObjectiveThe goal of the study was to investigate the genetic and molecular basis of a novel syndrome of marked hyperglucagonemia and pancreatic α cell hyperplasia...Full Text Available
BackgroundThis in vitro study was conducted to compare the accuracy of two digital image receptors in identifying the location of tip of a fine endodontic file and radiographic apex...Full Text Available
Resistance and tolerance are two types of host defense mechanisms that increase fitness in response to fungi. Several genetic polymorphisms in pattern recognition receptors, most remarkably Toll-like receptors (TLRs), have been described to influence resistance and tolerance to aspergillosis in distinct clinical settings. TLRs on dendritic cells pivotally contribute in determining the balance between immunopathology and protective immunity to the fungus. Epithelial cells also contribute to this balance via selected TLRs converging on indoleamine-2,3-dioxygenase (IDO). Studies in experimental hematopoietic transplantation confirmed the dichotomy of pathways leading to resistance and tolerance to the fungus providing new insights on the relative contribution of the hematopoietic/nonhematopoi...
Trastuzumab increases survival amongst women with human epidermal growth factor receptor (HER)-2 receptor positive metastatic breast cancer, but maternal and fetal risks are associated with advanced disease and its treatment in pregnancy. We present a case of a primigravid with HER-2 positive metastatic breast cancer who received trastuzumab throughout pregnancy. She presented with cerebral metastases, requiring surgical decompression and resection. Reversible oligohydramnios developed during pregnancy. Fetal safety data on trastuzumab in pregnancy is limited, but case reports suggest a recurring pattern of (mostly reversible) oligohydramnios.
The possibilities for therapy in the field of severe cardiac insufficiency have been extended in recent years by the introduction of novel agents endowed with a positive inotropic action. These substances may be arranged in two large classes: sympathomimetic agents and "non sympathomimetic--non digitalis-like" inotropic agents. The stimulant action of noradrenaline, adrenaline and isoproterenol on beta-adrenergic myocardial receptors has been clearly demonstrated but the usefulness of these medicines is limited by their positive chronotropic and arrhythmogenic actions. Dopamine and dobutamine have proved to be very useful in the treatment of patients in intensive care units. However, the exclusively intravenous route of administration limits their importance to the medium or long term. Several compounds, which are active by the oral route, have been the subject of therapeutic trials for the short or medium term. The problems posed by their use result, in the first ...
PACAP (pituitary adenylate cyclase activating polypeptide) is widely distributed neuropeptide acting via three subtypes of receptors, PAC(1), VPAC(1) and VPAC(2). Here we examined the localisation and nature of PACAP-immunoreactive nerves in the rat thyroid and parathyroid glands and defined the distribution of PAC(1), VPAC(1) and VPAC(2) receptor mRNA's. In the parathyroid gland a large number of nerve fibres displaying PACAP-immunoreactivity were distributed beneath the capsule, around blood vessels and close to glandular cells. Most of the PACAP-nerves were sensory, since they co-stored CGRP (calcitonin-gene-related peptide) and were sensitive to capsaicin-treatment. mRNA's for PAC(1) and VPAC(2) receptors occurred in the parathyroid gland, mainly located in the glandular cells. In the thyroid gland PACAP-immunoreactive nerve fibres were associated with blood vessels, thyroid follicles and parafollicular C-cells. A high ...
Screening of a human placenta lambdagt11 library has led to the isolation of the cDNA for the human ..beta../sub 1/-adrenergic receptor (..beta../sub 1/AR). Used as the probe was the human genomic clone termed G-21. This clone, which contains an intronless gene for a putative receptor, was previously isolated by virtue of its cross hybridization with the human ..beta../sub 2/-adrenergic receptor (..beta../sub 2/AR). The 2.4-kilobase cDNA for the human ..beta../sub 1/AR encodes a protein of 477 amino acid residues that is 69% homologous with the avian ..beta..AR but only 54% homologous with the human ..beta../sub 2/AR. This suggests that the avian gene encoding ..beta..AR and the human gene encoding ..beta../sub 1/AR evolved from a common ancestral gene. RNA blot analysis indicates a message of 2.5 kilobases in rat tissues, with a pattern of tissue distribution consistent with ..beta../sub 1/AR binding. This pattern is quite ...
Consideration is given to results of investigation into thorium complexing with morin (H_2Mor) in extraction systems containing different carboxylic acids as well as different salt background. The obtained data enabled to suggest the method of photometric determination of thorium in the form of Th(HMor)_2Benz_2 different-ligand complex (where Benz-anion of benzilic acid) with 0.25 #mu#g/ml detection limit.
Model phosphate-metal solvation complexes have been studied by ab-initio self-consistent-field techniques. The complexes studied include (RO)2PO2-(R = H or CH3) with Li+, Na+, K+, Be++, Mg++, Ca++,...Full Text Available
The concept of the modern data acquisition system and some functional specialties of the programming software--Visual Basic 6.0 are introduced. The construction and theory of the hardware and the designing principle of the software are described. Experimental results showed that the real-time data acquisition rate was as high as 10 times per second in the system. And the relative standard uncertainty of the measurement was less than 0.5%. (authors)
The application of kinetic probes that allow one to determine relative reactivities of biologically relevant substrates with oxidizing intermediates in the Fenton reagent (H2O2 plus Fe2+ in acidic aqueous...Full Text Available
The nanocrystallization process of amorphous Fe_7_3_._5Si_1_3_._5B_9Nb_3Cu_1 was investigated by active screen plasma nitriding (ASPN) treatment at temperatures ranging from 410 "oC to 560 "oC for 3 h in two gas mixtures of 75% N_2-25% H_2 and 25% N_2-75% H_2 at 5 mbar atmosphere. The amorphous ribbons were then annealed under vacuum at the same time and temperatures mentioned above. The structure of the samples was analyzed using various techniques such as X-ray diffraction (XRD), atomic force microscopy (AFM) and differential scanning calorimetry (DSC). Microhardness measurements, electrical resistivity and Vibrating Sample Magnetometer (VSM) were used to study mechanical, electrical and magnetic properties of the samples, respectively. It was observed that the ASPN treatment leads to finer grain size and higher crystalline volume fraction and modifies the structural features of Fe(Si) phase. The ...
The second in a series of flights to assemble the Japanese segment of the International Space Station saw the mammoth Kibo module delivered to the complex complements of Discovery and its crew on the STS-124 mission. Kibo, the Japanese word for u201chopeu201d would house dozens of experiments and serve as a platform for external payloads brought to the complex on subsequent Shuttle flights and the Japanese u201cKounotoriu201d H-2 Transfer Vehicle cargo ship.
Bovine microvascular endothelial cells (MEC) were able to degrade the H2O2 generated by phorbol myristate acetate-activated bovine neutrophils or by glucose oxidase with a maximal capacity of 4.0 +/-...Full Text Available
The rapid corrosion of carbon steels in high temperature, acid chloride solutions is shown to be rate limited by the anodic reaction, 3Fe + 4H_2O = Fe_3O_4 + 8H"+ + 8e"-, based on experiments which find that the corrosion rate in 0.1M NiCl_2 solution has an activation energy of 60 kJ/ mole and is unaffected by adding NaCl or by replacing NiCl_2 with PtCl_4. (author).
Biased above threshold (VT), pulsed photocurrent (u) measurements on windowed silicon Pd gate MOS capacitors are shifted (DV) negatively by H2/N2, whereas Au gates shift positively under NO2/air. Below VT, the shifts are reversed by adjustments of interface state population. Minor temperature increases may coax the device from inversion to depletion, inducing sign reversal of the chemical response.
Photon yields were measured from Cu(110) bombarded by H"+, H_2"+ and He"+ with different energies. The energy dependence is different from previous studies at perpendicular incidence. A calculation of the energy dependence of resonant charge capture into the n=3 state of H is compared with experiment. (G.Q.).
Shiga toxin (Stx)-producing Escherichia coli (STEC) strains are a diverse group of food-borne pathogens with various levels of virulence for humans. In this study, we describe the use...Full Text Available
Histone-beta-galactosidase protein fusions were used to identify the domain of yeast histone 2B, which targets this protein to the nucleus. Amino acids 28 to 33 in H2B were required for nuclear localization...Full Text Available
We have purified and characterized two peptides, named KAaH1 and KAaH2 (AaH polypeptides 1 and 2 active on K+ channels, where AaH stands for Androctonus australis Hector),...Full Text Available
Parkinson's disease (PD) is the most common neurodegenerative movement disorder. Mutations in PTEN-induced kinase 1 (PINK1) are a frequent cause of recessive PD. Autophagy, a pathway for clearance of protein aggregates or impaired organelles, is a newly identified mechanism for PD development. However, it is still unclear what molecules regulate autophagy in PINK1-silenced cells. Here we report that autophagosome formation is promoted in the early phase in response to PINK1 gene silencing by lentivirus transfer vectors expressed in mouse striatum. Reduced PP2A activity and increased phosphorylation of PP2A at Y307 (inactive form of PP2A) were observed in PINK1-knockdown dopaminergic cells and striatum tissues. Treatment with C2-ceramide (an agonist of PP2A) reduced autophagy levels in PINK...
PurposeWe investigated the efficacy and safety of degarelix treatment and the effects of switching from leuprolide to degarelix in an ongoing extension study with a median 27.5-month followup of a pivotal 1-year prostate cancer trial. Materials and MethodsPatients who completed a 1-year pivotal phase III trial continued on the same monthly degarelix maintenance dose (160 or 80 mg in 125 each), or were re-randomized from leuprolide 7.5 mg to degarelix 240/80 mg (69) or 240/160 mg (65). Data are shown on the approved degarelix 240/80 mg dose. The primary end point was safety/tolerability and the secondary end points were testosterone, prostate specific antigen, luteinizing hormone and follicle-stimulating hormone responses, and prostate specific antigen failure and progression-free survival....
Observational evidence is presented for the nucleation of condensation nuclei (CN) in the clear air adjacent to an isolated, marine, cumulus cloud. Two separate regions of particle nucleation are identified: one located above the cloud top, and the second located downwind of the cloud near the level of the anvil outflow. The regions of high CN concentrations were located in extremely clean marine air, with unactivated aerosol surface area (excluding the nucleation mode) less than 2 sq micrometers/cu cm, air temperature -31 C, and higher relative humidities than the undisturbed environment. Vertical profile measurements downwind of the cloud showed that CN concentrations at the level of the anvil outflow (4.9 km) were 8 times greater than at any other level between the surface and 5.3 km. A conceptual model is formulated in which aerosol particles, sulfur dioxide (SO2), sulfuric acid vapor (H2SO4), dimethyl sulfide (DMS), and ozone (O3) from the ...
The spike (S) protein of severe acute respiratory syndrome coronavirus (SARS-CoV) has two major functions: interacting with the receptor to mediate virus entry and inducing protective immunity. Coincidently, the receptor-binding domain (RBD, residues 318-510) of SAR-CoV S protein is a major antigenic site to induce neutralizing antibodies. Here, we used RBD-Fc, a fusion protein containing the RBD and human IgG1 Fc, as a model in the studies and found that a single amino acid substitution in the RBD (R441A) could abolish the immunogenicity of RBD to induce neutralizing antibodies in immunized mice and rabbits. With a panel of anti-RBD mAbs as probes, we observed that R441A substitution was able to disrupt the majority of neutralizing epitopes in the RBD, suggesting that this residue is critical for the antigenic structure responsible for inducing protective immune responses. We also demonstrated that the RBD-Fc bearing R441A mutation could not ...
It is now known that various growth factors may also act in the central nervous system. Among them, it has recently been shown that epidermal growth factor (EGF) and insulin-like growth factor I (IGF-I) may possess trophic effects in the mammalian brain. We report here on the respective autoradiographic distribution of ["1"2"5I]EGF and ["1"2"5I]IGF-I receptor binding sites in the rat brain, both during ontogeny and in adulthood. It appears that ["1"2"5I]EGF sites are mostly found in the rat forebrain during brain development. On the other hand, ["1"2"5I]IGF-I sites are more widely distributed both during ontogeny and in adulthood. These results reveal the plasticity of the expression of EGF and IGF-I receptor sites in the mammalian brain. This could be relevant for the respective role of these two growth factors in the development and maintenance of neuronal function.
The synthesis of (1',3'-{sup 3}H)4-(4'-azido-5',6',7',8'-tetrahydro-5'5'8',8'-tetramethyl-2'-anthracenyl)benzoic acid is described. This retinoid was designed as a photoaffinity probe of the receptor sites of cellular retinoic acid-binding protein and the nuclear retinoic acid receptor protein. The ({sup 3}H)azidoretinoid was prepared from 1,2,3,4-tetrahydro-1,1,4,4-tetra-methyl-7-(4-methylphenyl)-5-nitroanthracene in five steps in 15% yield (89% radiochemical purity by HPLC). {sup 1}H and {sup 3}H NMR was used to confirm the sites of {sup 3}H substitution on the ring. (author).
The measurement of physiological parameters in man is possible with the help of positron emission tomography (PET) and radiopharmaceuticals labeled with short lived positron emitters as C 11, N 13, O 15 and F 18. With the use of this substances it is possible to make a tomographic map defining regional metabolic parameters in normal and diseased brain. This technique has therefore also be named 'in vivo autoradiography'. The possibility of applying C 11 or F 18 labeled deoxyglucose with PET for detecting regional and local changes in cerebral metabolic rate of glucose in brain development in children of 5 days to 1 year of age is discussed. Beyond this a relationship between cerebral metabolic rate of glucose, cerebral blood flow and cerebral metabolic rate of oxygen by use of this technique after inhalation of O 15 and C 11-labeled CO_2 is shown. Attention is drawn to the application of C 11-methyl-spiperone and PET to visualize dopamine receptor density in the ...
Aims: Serotonin (5-hydroxytryptamine 3; 5-HT3) receptors are involved in chemotherapy-induced nausea and vomiting (CINV), and 5-HT3 antagonists are part of the `gold standard' antiemetic treatment during chemotherapy. We investigated the correlation of common variants in 5-HT3 receptor subunit genes with the occurrence of CINV. Materials & methods: A total of 110 previously characterized chemotherapy-naive women with primary breast cancer treated with anthracycline-containing chemotherapy served as a study group for mutational analysis by direct sequencing. Eight common SNPs in the 5-HT3 receptor genes, HTR3A, HTR3B, HTR3D and HTR3E, were selected for association analysis. Results: A nonsynonymous variant in HTR3D, p.G36A (rs6443930), was found to be over-represented in nonresponders, assu...
A hallmark of congestive heart failure (CHF) is the activation of the cardiac endocrine system, in particular atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP). The natriuretic peptides are a group of structurally similar but genetically distinct peptides that have diverse actions in cardiovascular, renal, and endocrine homeostasis. ANP and BNP are of myocardial cell origin and C-type natriuretic peptide (CNP) is of endothelial origin. ANP and BNP bind to the natriuretic peptide-A receptor (NPR-A), which, via 3',5'-cyclic guanosine monophosphate (cGMP), mediates natriuresis, vasodilatation, renin inhibition, antimitogenesis, and lusitropic properties. CNP lacks natriuretic actions but possesses vasodilating and growth inhibiting actions via the guanylyl cyclase-linked natriuretic peptide-B receptor. All three peptides are cleared by the natriuretic peptide-C receptor and degraded by the ectoenzyme neutral ...
This progress report covers period from Nov. 1, 1989 to Aug. 31, 1990. The long term objective was to develop receptor-binding radiotracers for SPECT or PET imaging of CNS or peripheral nervous system. The specific chemistry aims, as understood on the basis of past findings, were: to synthesize and develop a more polar analogs of 4IQNB, possessing similar binding characteristics but eliminated more rapidly from the surrounding tissues and the target organ, to design a method of introducing a technetium chelating group onto a molecule or cholinergic agent without drastic lowering of its apparent affinity, to synthesize and develop radiotracers based on m-AChR antagonists selective for one of the subtypes of the receptor. The chemistry service aims were to prepare and characterize (R,R)- and (R,S)-4IQNB and derivatives, to provide the triazene intermediate to other investigators, and to provide ({sup 123}I)4IQNB for in vivo imaging. The ...
We report the isolation of cDNA clones for the mouse {alpha}7 neuronal nicotinic acetylcholine receptor subunit (gene symbol Acra7), the only nicotinic receptor subunit known to bind a-bungarotoxin in mammalian brain. This gene may have relevance to nicotine sensitivity and to some electrophysiologic findings in schizophrenia. The mouse {alpha}7 subunit gene encodes a protein of 502 amino acids with substantial identity to the rat (99.6%), human (92.8%), and chicken (87.5%) amino acid sequences. The {alpha}7 gene was mapped to mouse chromosome 7 near the p locus with the following gene order from proximal to distal: Myod1-3.5 {+-}1.7 cM-Gas2-0.9 cM {+-} 0.9 cM-D7Mit70-1.8 {+-} 1.2 cM- Acra7-4.4 {+-}1.0 cM-Hras1-ps11/Igf1r/Snrp2a. The human gene was confirmed to map to the homologous region of human chromosome 15q13-q14. 26 refs., 3 figs.
The effects of atrial natriuretic peptide (ANP), oxytocin (OT) and vasopressin (AVP) on guanylate cyclase activity and cyclic GMP accumulation were examined, since these hormones appear to be intimately associated with blood pressure and intravascular volume homeostasis. ANP was found to increase cyclic GMP accumulation in ten cell culture systems, which were derived from blood vessels, adrenal cortex, kidney, lung, testes and mammary gland. ANP receptors were characterized in intact cultured cells using {sup 125}I-ANP{sub 8-33}. Specific {sup 125}I-ANP binding was saturable and of high affinity. Scratchard analysis of the binding data for all cell types exhibited a straight line, indicating that these cells possessed a single class of binding sites. Despite the presence of linear Scatchard plots, these studies demonstrated that cultured cells possess two functionally and physically distinct ANP-binding sites. Most of the ANP-binding sites in cultured cells have a ...
Abstract. Objective: Lapatinib (Tykerb, GW572016), a potent inhibitor of the catalytic activities of epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) (ErbB2), inhibits population growth of selected EGFR and HER2 overexpressing cell lines. Previous studies with a small number of cell lines suggest a correlation between overexpression of EGFR and/or HER2 and sensitivity to growth inhibition by lapatinib; however, the precise determinants of lapatinib selectivity for tumour and/or other cells remain unclear. Materials and methods: To clarify the determinants of its selectivity in cultured cells, lapatinib-induced cell population growth inhibition and relative EGFR and HER2 protein expression were quantified in 61 different human tumour cell lines fro...
Structural instability of wild-type fibroblast growth factor (FGF)-1 and its dependence on exogenous heparin for optimal activity diminishes its potential utility as a therapeutic agent. Here we evaluated FGFC, an FGF1:FGF2 chimeric protein, for its receptor affinity, absolute heparin-dependence, stability and potential clinical applicability. Using BaF3 transfectants overexpressing each FGF receptor (FGFR) subtype, we found that, like FGF1, FGFC activates all of the FGFR subtypes (i.e., FGFR1c, FGFR1b, FGFR2c, FGFR2b, FGFR3c, FGFR3b and FGFR4) in the presence of heparin. Moreover, FGFC activates FGFRs even in the absence of heparin. FGFC stimulated keratinocytes proliferation much more strongly than FGF2, as would be expected from its ability to activate FGFR2b. FGFC showed greater struct...
This paper proposes a model to explain tritium release behavior of an irradiated Li_4SiO_4 sample made by Forschungszentrum Karlsruhe. The release curves were obtained in a series of experiments carried out using out-pile temperature programmed desorption techniques in the Kyoto University Reactor (KUR). Tritium release curves obtained for different purge gas compositions (N_2, N_2 + H_2, N_2 + H_2O) were compared for selection of suitable conditions to determine the apparent diffusivity of tritium in a crystal grain of Li_4SiO_4.In the model formation, some mass transfer steps in the bulk of the crystal grain and those on the surface of the grain were taken into account, which were diffusion of tritium in the grain, adsorption and desorption of water on the surface of the grain, two types of isotope exchange reactions, and water formation reaction by the addition of hydrogen to the purge ...
Copper(II) complex coordinated with cyclam-type macrocyclic tetramine, C-meso-1,5,8,12-tetramethyl-1,4,8,11-tetraazacyclotetradecane (2Cdmc) has been synthesized and characterized by single crystal X-ray crystallographic analysis and UV?Vis absorption spectra. Solved molecular structure of [Cu(2Cdmc)(H2O)]Cl2?2H2O (1) revealed that macrocyclic ligand 2Cdmc was in the most stable trans-III structure, but the C-methyl groups of 2Cdmc adopted energetically unfavorable axial configuration (C-axial). This complex 1 is the second example of complex of cyclam-type tetramine with only axially oriented C-methyl groups. This complex adopted five-coordinated square-pyramidal geometry with one water molecule occupying one of the two apical sites. Network of hydrogen bonds involving counter anions (Cl?...
Reaction between [V^I^VO(acac)2] and the ONN donor Schiff base Hpydx-aepy (I) (Hpydx-aepy=Schiff base obtained by the condensation of pyridoxal and 2-aminoethylpyridine) resulted in the formation of a complex [V^I^VO(acac)(pydx-aepy)] (1). Addition of aqueous 30% H2O2 to 1 yields the poor stable oxidoperoxidovanadium(V) complex [V^VO(O2)(pydx-aepy)] (2). Its formation has also been demonstrated in solution by treating 1 with H2O2 in methanol. Reaction of vanadium exchanged zeolite-Y with I in methanol followed by aerial oxidation gave zeolite-Y encapsulated dioxidovanadium(V) complex, abbreviated as [V^VO2(pydx-aepy)]-Y (4). The crystal and molecular structure of 1 has been determined, confirming the ONN binding mode of the ligand. The encapsulated complex [V^VO2(pydx-aepy)]-Y (4) catalyse...
TSS (thermal swing sublimation) method was studied which uses vaporization heat and sensible heat of LNG for solidification and separation of CO2 gas in waste gases of LNG-fired combined cycle power generation system. In experiment, the mixed gas composed of CO2, H2O and N2 was used for simulating waste gas of LNG-fired combined cycle power generation systems, and the growth behavior of ice and dry ice was studied for developing dry ice making technology under low-temperature condition. As the experimental result, the following were clarified: various crystal structures depending on cooling temperature, the effect of gas flow rate on peeling of surface precipitated solids, and solidification characteristics of H2O/CO2 mixed gas. The growth rate of precipitated solid film thickness decreased with an increase in gas flow rate, while increased with CO2 concentration. The shape of a dry ice sublimator ...
Spectroscopic properties of Er"3"+ : CBS (CdSO_4 + B_2O_3 and R_2SO_4 + CdSO_4 + B_2O_3, R_2SO_4 = Li_2SO_4.H_2O, Na_2SO_4, K_2SO_4 and Gd_2(SO_4)_3.8H_2O) glasses are reported. The assigned energy level data of Er"3"+(4f"1"1) in these glasses are analysed in terms of a parametrized model Hamiltonian. The standard deviations of the data fits are between 39 and 47 cm"-"1 so that the energy level schemes of the Er"3"+(4f"1"1) ions in borosulphate (CBS) glasses are reasonably well reproduced. Radiative properties for the fluorescent levels of Er"3"+ : CBS glasses are determined by using the Judd-Ofelt theory. The potential laser transitions are identified with the help of predicted radiative properties which are compared and discussed with similar results. (author).
The behavior of lead in the graphite furnace during the individual steps of the temperature program was investigated by means of "2"0"3Pb as a radiotracer. The matrix systems include HCl and HNO_3 solutions, 1% NaCl solution, blood, serum, urine, and the solid samples bovine liver and orchard leaves. Without matrix modificaton, a pyrolysis temperature of up to 500"0C can be used for all samples. Significant stabilization effects can be achieved in the preatomization steps by using NH_4H_2PO_4 and ammonia as matrix modifiers and by addition of hydrogen to the flowing argon gas. It was found that the use of a L'vov platform also helps to eliminate the matrix effects. With respect to lead stabilization and elimination of matrix effects, optimum experimental conditions are achieved by simultaneous use of a L'vov platform and NH_4H_2PO_4 as the matrix modifier. 34 references, 5 figures, 1 table.
The pozzolanic behaviour of compound-activated red mud-coal gangue has been investigated through TG, DTA, XRD, FTIR and 27Al MAS NMR. From viewpoint of reaction kinetics, it is found that the pozzolanic reaction mechanism of the compound-activated red mud-coal gangue - lime system is clearly consistent with diffusion control up to 14 days, and the reaction rate constant calculated from Jander equation decreases with the increase of CaO addition in the system. The hydration products formed in the red mud-coal gangue - lime systems at ambient temperature are essentially aluminous C-S-H and Ca3Al2O6.xH2O. From TG analysis results, it is thought that the high amount of Ca(OH)2 in the pastes of studied system is not conducive to the continual increase of non-evaporable water content of the hydration products. Of particular interest, 27Al MAS NMR proved to be an effective technique to obtain valuable information of Al[4] in C-S-H and Al[6] in ...
As for surface treatment of steel, the ion nitriding method has a lot of advantages and is practically used, while the plasma nitriding is known as a method which is faster in nitriding than the ion nitriding method. However, there are few reports and many unclear points on the plasma nitriding method. In this study, the plasma nitriding of pure iron and SUS304 is conducted using r.f. nitrogen plasma glow discharge to examine composition of the nitrided layers, microstructures, nitriding rate, etc. Moreover, by exposing the specimen once nitrided to H2 plasma, a phenomenon that nitrogen comes out of the specimen surface is examined. It is found from the result that the nitrided layer is divided into a compound layer and a diffusion layer in order from the surface, that in case of pure iron, the compound layer grows predominantly at a low temperature, and the diffusion layer grows predominantly at a high temperature, that in case of SUS304, both ...
Combination agents comprising two different pharmacophores with the same biological target have the potential to show additive or synergistic activity. Bis(thiosemicarbazonato)copper(II) complexes (e.g. 64Cu-ATSM) and nitroimidazoles (e.g. 18F-MISO) are classes of tracer used for the delineation of tumor hypoxia by positron emission tomography (PET). Three nitroimidazole-bis(thiosemicarbazonato)copper(II) conjugates were produced in order to investigate their potential as combination hypoxia imaging agents. Two were derived from the known bifunctional bis(thiosemicarbazone) H2ATSM/A and the third from the new precursor diacetyl-2-(4-N-methyl-3-thiosemicarbazone)-3-(4-N-ethylamino-3-thiosem icarbazone) - H2ATSM/en. Oxygen-dependent uptake studies were performed using the 64Cu radiolabelled ...
The interfacial tension g of the hexane solution of 1H,1H,10H,10H-perfluorodecane-1,10-diol (FC10diol) and 1H,1H,2H,2H-perfluorododecanol (TFC12OH) mixture against water was measured as a function of the total molality m and composition of TFC12OH in the mixture X2 at 298.15K under atmospheric pressure. The interfacial pressure p vs. mean area per adsorbed molecule A curves and the phase diagram of adsorption (PDA) were constructed in order to shed light on the effect of the molecular orientation on the state of and the miscibility of FC10diol and TFC12OH in the adsorbed film. The p vs. A curves demonstrated that the mixed system exhibits three kinds of film states, parallel-condensed, normal-condensed, and multilayer states, depending on m and X2. The PDA indicated that film composition X...
The attenuation of gamma rays in some fatty acids, viz. formic acid (CH_2O_2), acetic acid (C_2H_4O_2), propionic acid (C_3H_6O_2), butyric acid (C_4H_8O_2), n-hexanoic acid (C_6H_1_2O_2), n-caprylic acid (C_8H_1_6O_2), lauric acid (C_1_2H_2_4O_2), myristic acid (C_1_4H_2_8O_2), palmitic acid (C_1_6H_3_2O_2), oleic acid (C_1_8H_3_4O_2) and stearic acid (C_1_8H_3_6O_2), has been measured at the photon energies 81, 356, 511, 662, 1173 and 1332 keV. Experimental values for the molar extinction coefficient, the effective atomic number and the electron density have been derived and compared with theoretical calculations. There is good agreement between experiment and theory.
A variety of platinum(II) complexes of methimazole (2-mercapto-1-methylimidazole; HImS=neutral form and ImS=thiolate form), coordinated in both thione and thiolate forms, have been isolated by reacting methimazole with [PtCl(terpy)]Cl (terpy=2,2prime:6prime,2Prime terpyridine), [PtCl2(bipy)] (bipy=bipyridine), [PtCl2(o-phen)] (o-phen=o-phenanthroline), [PtCl2(CH3CN)2] and [PtCl2(COD)] (COD=1,5-cyclooctadiene). These complexes were characterized by electronic absorption, IR and NMR (1H, 13C, 195Pt) spectroscopies. Molecular structure of [Pt(bipy)(HImS)2]Cl23H2O (3a3H2O) has been established by single crystal X-ray crystallography. Platinum thiolate complex, [Pt(ImS)2(HImS)2] (5), could be obtained by treatment of [Pt(HImS)4]Cl2 with sodium methoxide in methanol. The solution of 5 in organic...
Semi-inclusive pi+ electroproduction on protons has been measured with the CLAS detector at Jefferson Lab. The measurement was performed on a liquid-hydrogen target using a 5.75 GeV electron beam. The complete five-fold differential cross sections were measured over a wide kinematic range in Q2, x, z, and pT and over the complete range of azimuthal angles, phi, enabling us to separate the different structure functions, H2+eps*H1, H3 and H4. Our measurements of H2 at low-x were found to be in fairly good agreement with pQCD calculations, suggesting a precocious factorization of the process. Indeed, the conventional f(x)*D(z) term can account for almost all of the observed cross section, even at small z. The measured xF-distributions are in qualitative agreement with high energy data, which suggests a surprising numerical similarity between the spectator diquark fragmentation in the present reaction and ...
One salt and two Cu(II) complexes (H2hsm)(ox), 1, [Cu(hsm)(ox)], 2, and [Cu(hsm)(ox)H2O], 3, have been synthesized and X-ray characterized (hsm is histamine and ox2? is the oxalate dianion). Starting from the prochiral tetracoordinated complex 2, pentacoordinated complex 3 crystallizes as a racemic mixture of the enantiomeric ? and ? isomers, in space group P21/c. In all cases, the side chain of the hsm group is gauche, allowing the formation of strong hydrogen bonds in the salt 1, and to chelate the metal center in complexes 2 and 3. The combination hsm/ox seems to favor the formation of 2D supramolecular structures (planes or wavy planes), through efficient networks of N?H???O hydrogen bonds. Cell parameters: 1, P21/c, a?=?6.260 (2) ?, b?=?11.500 (4) ?, c?=?12.525 (4) ?, ??=?104.047 (17)...
The usually low wear resistance of titanium materials can be increased by the thermochemical surface treatment nitriding. In result of comparative investigations of gas and plasma nitriding it will be shown that it is possible to obtain a specific variation of the properties in the highly stressed case by means of these both technologies on example of the (#alpha#+#beta#) alloy Ti-6Al-4V. Gas and plasma nitriding was carried out in the temperature range from 650 to 800 C over 4 to 48 h in different gas atmospheres, i.e. 100% NH_3 (gas), 100% N_2 (gas and plasma), 20% H_2 + 80% N_2 and 20% Ar + 20% H_2 (plasma). The temperature range was fixed in the middle of (#alpha#+#beta#) region, because the core properties are influenced negative in the field of #beta#-transustemperature. The relations between the applied nitriding technologies, the layer structure (chemical, phases, geometrical) and selected layer ...
The PERMCAT process chosen for the final clean-up stage of the Tokamak Exhaust Processing system of the ITER tritium plant combines in a single component a catalytic reactor and a permeator using Pd/Ag membranes. This study covers the mechanical behaviour of a Pd/Ag membrane under different operating conditions. The consequences of hydrogen uptake by the membrane during nominal operation but also during off-normal events are presented. Depending on the operating conditions, expansions around 2% and significant deformations are observed. Different mechanical designs of PERMCAT reactors are then discussed. The first generation comprises finger-type membranes and two new mechanical designs use either additional edge welded bellows or a special corrugated Pd/Ag membrane. These upgraded designs improve the robustness and simplify the geometry of the component. The experimental validation of these new units has been carried out based on the measurements of the processing capabilities with ...
A solar-driven 10-ton LiBr/H2O single-effect absorption cooling system has been designed and installed at the School of Renewable Energy Technology (SERT), Phitsanulok, Thailand. Construction took place in 2005, after which this system became fully operational and has been supplying cooling for our main testing buildings air-conditioning. Data on the systems operation were collected during 2006 and analyzed to find the extent to which solar energy replaced conventional energy sources. Here, we present these data and show that the 72m2 evacuated tube solar collector delivered a yearly average solar fraction of 81%, while the remaining 19% of thermal energy required by the chiller was supplied by a LPG-fired backup heating unit. We also show that the economics of this cooling system are domi...
The addition of paraquat (methyl viologen) to a growing culture of Escherichia coli K-12 led within 1 hr to a 10- to 20-fold increase in the level of endonuclease IV, a DNase for apurinic/apyrimidinic sites. The induction was blocked by chloramphenicol. Increases of 3-fold or more were also seen with plumbagin, menadione, and phenazine methosulfate. H_2O_2 produced no more than a 2-fold increase in endonuclease IV activity. The following agents had no significant effect: streptonigrin, nitrofurantoin, tert-butyl hydroperoxide, #gamma# rays, 260-nm UV radiation, methyl methanesulfonate, mitomycin C, and ascorbate. Paraquat, plumbagin, menadione, and phenazine methosulfate are known to generate superoxide radical anions via redox cycling in vivo. A mutant lacking superoxide dismutase was unusually sensitive to induction by paraquat. In addition, endonuclease IV could be induced by merely growing the mutant in pure O_2. The levels of endonuclease ...
We report on the detection of SiO and water masers toward a newly found bipolar nebula, IRAS 19312+1950. This object exhibits extreme red IRAS color log (F25/F12)=0.5 and log (F60/F25)=0.7 and a nebulosity having a size of about 30" extended to the South-West in the 2MASS near-infrared image. Toward this object, we have detected emission from the H2O 6(1,6)-5(2,3) transition, the SiO J=1-0, v=1 and 2, and J=2-1, v=1 transitions, and the SO 2(2)--1(1) and H13CN J=1-0 transitions. The thermal lines of SO and H13CN are shifted by about 12 km/s in radial velocity with respect to the maser lines, indicating that thermal emission comes from the background molecular cloud. However, the SiO J=2-1, v=2 spectrum shows another component of SiO emission separated by 26 km/s from the main component, that might be formed in a rotating or expanding shell.
We present ultraviolet spectra of Mira's companion star from the Space Telescope Imaging Spectrograph (STIS) instrument on board the Hubble Space Telescope (HST). The companion is generally assumed to be a white dwarf surrounded by an accretion disk fed by Mira's wind, which dominates the UV emission from the system. The STIS UV spectrum is dominated by numerous, narrow H2 lines fluoresced by H I Ly-alpha, which were not detected in any of the numerous observations of Mira B by the International Ultraviolet Explorer (IUE). The high temperature lines detected by IUE (e.g., C IV 1550) still exist in the STIS spectrum but with dramatically lower fluxes. The continuum fluxes in the STIS spectra are also much lower, being more than an order of magnitude lower than ever observed by IUE, and also an order of magnitude lower than fluxes observed in more recent HST Faint Object Camera objective prism spectra from 1995. Thus, the accretion rate onto Mira ...
This study addresses the solar thermal decomposition of natural gas for the co-production of hydrogen and carbon black (CB) as a high-value nano-material with the bonus of zero CO2 emission. The work focused on the development of a medium-scale solar reactor (10kW) based on the indirect heating concept. The solar reactor is composed of a cubic cavity receiver (20cm-side), which absorbs concentrated solar irradiation through a quartz window by a 9cm-diameter aperture. The reacting gas flows inside four graphite tubular reaction zones that are settled vertically inside the cavity. Experimental results in the temperature range 1740-2070K are presented: acetylene (C2H2) was the most important by-product with a mole fraction of up to about 7%, depending on the gas residence time. C2H2 content i...
Hydrogen production from desugared molasses (DM) was investigated in both batch and continuous reactors using thermophilic mixed cultures enriched from digested manure by load shock (loading with DM concentration of 50.1 g-sugar/L) to suppress methanogens. H"2 gas, free of methane, was produced during batch cultivations, at different (DM) concentrations ranging from 1.5 g-sugars/L to 50.1 g-sugars/L. The highest yield of 237 ml-H"2/g-sugar was achieved during the DM batch fermentation at concentration of 2.1 g-sugars/L, whereafter the yield decreased with increasing DM concentration. The enriched hydrogen producing mixed culture achieved from the 16.7 g-sugars/L DM batch cultivation was immobilized on heat treated anaerobic sludge granules in an up-flow anaerobic sludge blanket (UASB) reac...
Abstract We present the first numerical,-N-body, hydrodynamical, chemical simulations of cosmic structure formation in the framework of non-Gaussian models. We study the impact of primordial non-Gaussianities on early chemistry (e-, H, H+, H-, He, He+, He++, H2, H+2, D, D+, HD, HeH+), molecular and atomic gas cooling, star formation, metal (C, O, Si, Fe, Mg, S) enrichment, Population-III (popIII) and Population-II-I (popII) transition and on the evolution of -visible- objects. We find that non-Gaussianities can have some consequences on baryonic structure formation at very early epochs, but the subsequent evolution at later times washes out any difference among the various models. When assuming reasonable values for primordial non-Gaussian perturbations, it turns out that they are responsi...
We have performed a detailed analysis of water clustering and percolation in hydrated Nafion configurations generated by classical molecular dynamics simulations. Our results show that at low hydration levels H2O molecules are isolated and a continuous hydrogen-bonded network forms as the hydration level is increased. Our quantitative analysis has established a hydration level (?) between 5 and 6 H2O/SO3- as the percolation threshold of Nafion. We have also examined the effect of such a network on proton transport by studying the structural diffusion of protons using the quantum hopping molecular dynamics method. The mean residence time of the proton on a water molecule decreases by two orders of magnitude when the ? value is increased from 5 to 15. The proton diffusion coefficient in Nafion at a ? value of 15 is about 1.1x10-5 cm2/s in agreement with experiment. The results provide quantitative ...
The flybys of Jupiter by the Voyager spacecraft in 1979, and over two decades later by Cassini in 2000, have provided us with unique datasets from two different epochs, allowing the investigation of seasonal change in the atmosphere. In this paper we model zonal averages of thermal infrared spectra from the two instruments, Voyager 1 IRIS and Cassini CIRS, to retrieve the vertical and meridional profiles of temperature, and the abundances of the two minor hydrocarbons, acetylene (C2H2) and ethane (C2H6). The spatial variation of these gases is controlled by both chemistry and dynamics, and therefore their observed distribution gives us an insight into both processes. We find that the two gases paint quite different pictures of seasonal change. Whilst the 2-D cross-section of C2H6 abundance is slightly increased and more symmetric in 2000 (northern summer solstice) compared to 1979 (northern fall equinox), the major trend of equator to pole ...