Search Results - (Author, Cooperation:D. Cox)

Cox, D. R.

Unknown

142 S.

English

2018-10-10

The American Association of Immunologists (AAI)

0022-1767

1550-6606

Medicine

2018-03-29

The American Society for Microbiology (ASM)

0022-538X

1098-5514

Medicine

2013-01-05

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Animals ; Base Sequence ; Caspase 9/*chemistry/genetics ; DNA/chemistry/genetics ; *DNA Cleavage ; Genetic Engineering/*methods ; Genetic Loci ; Genome/*genetics ; Humans ; Inverted Repeat Sequences/*genetics ; Mice ; Microarray Analysis/*methods ; Molecular Sequence Data ; Mutagenesis ; RNA/chemistry/genetics ; Recombinational DNA Repair ; Streptococcus pyogenes/enzymology/genetics

2015-06-13

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Adaptor Proteins, Signal Transducing/*immunology/metabolism ; Burkholderia/immunology ; Cytosol/chemistry/immunology ; Escherichia coli/immunology ; Flagellin/immunology ; Genetic Testing ; Gram-Negative Bacteria/*immunology/metabolism ; HEK293 Cells ; Host-Pathogen Interactions/genetics/*immunology ; Humans ; *Immunity, Innate ; Jurkat Cells ; NF-kappa B/immunology ; Neisseria gonorrhoeae/immunology ; Neisseria meningitidis/immunology ; RNA Interference ; Sugar Phosphates/analysis/*immunology/metabolism ; TNF Receptor-Associated Factor 6/immunology/metabolism

0008-6215

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Electronic Resource

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

In this paper both deuterium saturation measurements and gas-phase kinetic measurements of chemisorption of H2, D2, N2, CD4, CH4, C2H4, and C2H6 on neutral palladium clusters are reported. Saturation studies with D2 show that small palladium clusters can bind up to three deuterium atoms per palladium atom in the cluster, in contast to H/M ratios near unity typically reported for metal surfaces. In addition, the small palladium clusters exhibit pronounced discontinuities in deuterium uptake which may be indicative of structural transformations or selective desorption of deuterium. From the kinetic studies we find that, in general, the rate constants for a given size cluster towards different reagents tend to order as D2, H2〉N2〉C2H4〉CD4, CH4, C2H6. The shape of the reactivity pattern with the different reagents varies strongly with cluster size for clusters containing less than 25 atoms. Finally, an inverse hydrogen isotope effect is observed for both hydrogen and methane, i.e., the D2 and CD4 rate constants are significantly larger than those of H2 and CH4, respectively.

Electronic Resource

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

Zero electron kinetic energy (ZEKE) spectroscopy and photodetachment cross section measurements have been carried out on Au−6. The transition frequencies of ZEKE peaks and resonance peaks are nearly identical, consistent with the proposal that the excited negative ion of Au6 has a geometry quite similar to that of neutral Au6, and supporting the picture of the resonances as weakly bound "surface states.'' From these studies the 0–0 transition frequency between Au−6 and Au6 is measured to be 16 541±17 cm−1, and the vibrational frequencies for the neutral Au6 ground state, the Au−6 ground state, and the (Au−6)* anion excited electronic state are 107, 73, and 107 cm−1, respectively. Lastly, we observe evidence for a previously unreported resonance transition to the excited anion which we suggest is the 0–0 transition of Au−6 to (Au−6)*.

Electronic Resource

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

Well-defined librational excitations have been observed at energies of 2–3 meV in the low temperature ordered phase of solid C60. These relatively high energies imply a stiff orientational potential below the transition. The sharpness of the peaks indicates that this potential does not depend strongly on the axis of the angular displacement. The modes soften and broaden as the temperature approaches that of the orientational melting transition which occurs when the librational amplitude is a considerable fraction of nearest-neighbor interatomic angles.

Electronic Resource

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

Electronic Resource

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

This paper reports the observation of autodetaching resonances in photoelectron spectroscopy of Au−2 according to the process Au−2 +hν(large-closed-square)(Au−2)*(large-closed-square)Au2 +e−. They appear as sharp features superimposed upon a nearly constant signal associated with direct photodetachment process from Au−2 :Au−2 +hν(large-closed-square)Au2+e−. By altering the cluster expansion conditions, the dimer anion temperature can be varied. This leads to changes in the linewidth and relative intensities of the resonances and allows ground state and hot band transitions to be identified. The resonances correspond to electronic transitions to a long-lived excited state of Au−2 with a significantly lower vibrational frequency (128±2 cm−1) than that of the neutral ground state (190.9 cm−1), or even the anion ground state (149 cm−1). It decays via electronic autodetachment in a two-electron process similar to autoionization of neutral atoms.

Electronic Resource

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

Electronic Resource

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

The gas-phase reaction of positively charged niobium cluster ions Nb+x with normal and perdeuterobenzene has been studied using a fast-flow reactor and direct ion sampling techniques. Chemisorption of benzene onto the ion is facile, with the rate being essentially independent of x. However, both the resulting product distributions, consisting of species NbxC6H+m and NbxC6D+m with m=0,2,4,6, and the relative product yields not only display a dramatic dependence on cluster size, but are also remarkably similar to those previously observed for neutral Nbx using gentle, low-fluence, single-photon 6.42 eV photoionization. Direct observation of products with m≤6 indicates that both chemical dehydrogenation of benzene and desorption of hydrogen from the cluster ions must occur in the fast-flow reactor. Further, the relative yield of dehydrogenated products is found to increase substantially with increase in cluster "temperature.'' Complete dehydrogenation of benzene to m=0 is also found to occur for niobium cluster oxides NbxO+ containing 5–14 Nb atoms. The present results are discussed in terms of the mechanism of the dehydrogenation process, as well as with respect to their relevance in determining "true'' parent product distributions formed in reactions of the corresponding neutral clusters.

Electronic Resource

1089-7623

AIP Digital Archive

Physics

Electrical Engineering, Measurement and Control Technology

We have recently developed a high-resolution magnetic imaging system based on an array of five superconducting pickup coils located within 1 mm of room temperature. The pickup coils are 1.70 mm in diameter and spaced 2.5 mm apart allowing spatial resolution of order 1 mm. They are each connected to an rf SQUID and have a magnetic field sensitivity of 3 pT/(square root of)Hz. The system includes a three axis nonmagnetic translation table for mounting the sample, a stage for temperature control, and complete computer control of all functions.

Electronic Resource

1527-3458

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Significant physiologic changes occur during menopause. Evidence exists to suggest that estrogen may be neuroprotective under specific conditions. However, there are limitations in the neuroprotection afforded by standard hormone therapy. Accordingly, alternative agents with selected estrogenic effects may hold even greater promise rather than conventional hormone replacement therapy for the prevention and treatment of CNS injury. Recently, a variety of selective estrogen receptor modulators (SERMs) have been developed to retain the favorable and minimize the adverse side effects of estrogens. This review focuses on the CNS and known neuroprotective effects of two specific SERMs, raloxifene and arzoxifene. Recent studies hint that raloxifene and arzoxifene are neuroprotective and may preserve some elements of cognitive function. However, the mechanism of action is not well described and it is unclear if the beneficial effects of SERMs rely on activation of estrogen receptors.

Electronic Resource

1471-4159

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Abstract: The properties of muscimol, β-carboline (BC), and benzodiazepine (BZD) binding to crude synaptic membranes were studied in the spinal cord and cerebellum of rats. In cerebellar membranes, the density of high-affinity [3H]muscimol and [3H]6,7-dimethoxy-4-ethyl-β-carboline ([3H]BCCM) binding sites is almost identical to that of [3H]flunitrazepam ([3H]FLU) or[3H]flumazenil (Ro 15–1788; ethyl-8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5–α][1–4]benzodiazepine-3-carboxylate). In contrast to the cerebellum, the number of muscimol and BC binding sites in rat spinal cord is ∼20–25% of the number of FLU or flumazenil binding sites. Moreover, in spinal cord membranes, BC recognition site ligands displace [3H]-flumazenil bound to those sites, with low affinity and a Hill slope significantly 〈1; the potency of the different BCs in displacing [3H]flumazenil is 25–50-fold lower in the spinal cord than in the cerebellum. [3H]Flumazenil is not displaced from spinal cord membranes by the peripheral BZD ligand Ro 5–4864 (4′-chlorodiazepam), whereas it is displaced with low affinity and a Hill slope of 〈 1 (nH= 0.4) by CL 218,872 (3-methyl-6–(3-trifluoromethylphenyl)-1,2,4-triazolol[4,3-b]pyridazine). These data suggest that a large number of BZD binding sites in spinal cord (∼80%) are of the central-type, BZD2 subclass, whereas the BZD binding sites in cerebellum are predominately of the central-type. BZD1 subclass. In both cerebellar and spinal cord membranes, micromolar γ-aminobutyric acid (GABA) enhanced the binding of [3H]FLU; however, this effect is less efficacious and less potent in the spinal cord, observations indicating two possibilities: (a) that in spinal cord some of the BZD2 binding sites are not coupled to the GABAA binding sites, or (b) that they are coupled in a GABAA/BZD2 receptor complex containing a large proportion of BZD2 binding sites associated with a relatively small number of GABAA binding sites.

Electronic Resource

1471-4159

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

The effects of hypoxia and hypoglycaemia on the redox state in vitro have been studied. NADH and NAD+ were extracted simultaneously from superfused cerebral cortex slices and assayed by bioluminescence. The results show a nonsignificant increase in NADH and the redox ratio in „mild hypoxia,” whereas „severe hypoxia” produced an increase of over 200% in NADH and in the NADH/NAD+ ratio. When the glucose in the incubation medium was reduced from its control value of 10 mM to 0.5 mM, significant decreases in NADH and the redox ratio to 60% of control value were observed. Further decreasing the glucose to 0.2 mM gave lower levels of NADH and the redox ratio (40% of control). The effects on the redox state of alternative substrates to glucose were also tested. Re placement of glucose by 10 mM pyruvate decreased the NADH by 77% and the NADH/NAD+ ratio by 79%. Replacement of glucose with 10 mM lactate gave decreases of 70% and 71%, respectively, whereas in the presence of 15 mM 2-deoxyglucose and 5 mM glucose, the NADH was decreased by 56% and the ratio by 50%. The results are discussed in relation to levels of creatine phosphate and ATP, as well as evoked action potentials, observed from parallel studies.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

Soft-recovery plate impact experiments have been conducted to study the evolution of damage in polycrystalline Al2O3 samples. Examination of the recovered samples by means of scanning electron microscopy and transmission electron microscopy has revealed that microcracking occurs along grain boundaries; the cracks appear to emanate from grain-boundary triple points. Velocity-time profiles measured at the rear surface of the momentum trap indicate that the compressive pulse is not fully elastic even when the maximum amplitude of the pulse is significantly less than the Hugoniot elastic limit. Attempts to explain this seemingly anomalous behavior are summarized. Primary attention is given to the role of the intergranular glassy phase which arises from sintering aids and which is ultimately forced into the interfaces and voids between the ceramic grains. Experiments are reported on the effects of grain size and glass content on the resistance of the sample to damage during the initial compressive pulse. To further understand the role of the glass, plate impact experiments were conducted on glass with chemical composition comparable to that which is present in the ceramic. These experiments were designed to gain further insight into the possibility of "failure waves'' in glasses under compressive loading.

Electronic Resource

1077-3118

AIP Digital Archive

Physics

A previously unreported ferroelectric phase has been discovered in a highly homogeneous sample of PbZr0.52Ti0.48O3 by high-resolution synchrotron x-ray powder diffraction measurements. At ambient temperature the sample has tetragonal symmetry (at=4.037 Å, ct=4.138 Å), and transforms below ∼250 K into a phase which, unexpectedly, has monoclinic symmetry (am=5.717 Å, bm=5.703 Å, cm=4.143 Å, β=90.53°, at 20 K). The intensity data strongly indicate that the polar axis lies in the monoclinic ac plane close to the pseudocubic [111] direction, which would be an example of the species m3m(12)A2Fm predicted on symmetry grounds by Shuvalov. © 1999 American Institute of Physics.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

We have calculated the variations with temperature of the skew scattering contribution to the Hall effect for a Kondo-type ion. The conduction electron t matrix is calculated by using the single-ion Anderson model, and the 4f electrons' Green's function is evaluated by self- consistently solving a set of integral equations. Except for the asymptotic region T/Tk(very-much-greater-than)1, the Hall constant is not proportional to the susceptibility, nor does the constant change sign for realistic values of the parameters entering the theory.

Electronic Resource