Neurons in the hippocampal CA1 region are particularly sensitive to oxidative stress (OS), whereas those in CA3 are resistant. To uncover mechanisms for selective CA1 vulnerability to OS, we...Full Text Available
The epileptogenic and neurodegenerative effects of gamma-dendrotoxin, from Dendroaspis angusticeps, a specific blocker of a non-inactivating, voltage-sensitive K+ channel, were studied after focal injection into one dorsal hippocampus in rats pretreated with CGP040116, a N-methyl-D-aspartate (NMDA) receptor antagonist, and in rats bearing a monolateral surgical lesion of the Schaffer collaterals whose terminals originate from CA3 pyramids and release glutamate in the CA1 hippocampal area. Administration of 35 pmol gamma-dendrotoxin elicited in all of the treated animals (n=8) bilateral EEG discharges and damage to the hippocampal formation. Quantitation of the damage revealed significant bilateral neuronal cell loss in the CA1, CA3 and CA4 pyramidal cell layers. The lowest dose (0.35 pmol; n=4) of the toxin used did not ...
A fundamental property of neuronal networks in Ammon’s horn is that each area is comprised of a single glutamatergic cell population and various types of GABAergic neurons. Here we describe...Full Text Available
Evidence is presented for a distinctive type of hippocampal synaptic modification [previously described for a molluscan gamma-aminobutyric acid (GABA) synapse after paired pre- and postsynaptic excitation]:...Full Text Available
Despite their wide use, the physiological relevance of organotypic slices remains controversial. Such cultures are prepared at 5 days postnatal. Although some local circuitry remains intact, they develop...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
This report discusses the following: (1) improving models of vapor-dominated geothermal fields: the effects of adsorption; (2) adsorption characteristics of rocks from vapor-dominated geothermal reservoir at the Geysers, CA; (3) optimizing reinjection strategy at Palinpinon, Philippines based on chloride data; (4) optimization of water injection into vapor-dominated geothermal reservoirs; and (5) steam-water relative permeability.
The Gordon Research Conference (GRC) on 2004 Gordon Research Conference on Reversible Associations in Structure & Molecular Biology was held at Four Points Sheraton, CA, 1/25-30/2004. The Conference was well attended with 82 participants (attendees list attached). The attendees represented the spectrum of endeavor in this field coming from academia, industry, and government laboratories, both U.S. and foreign scientists, senior researchers, young investigators, and students.
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 ...
We report the results of the DC magnetization, neutron powder diffraction and neutron depolarization studies on the spin-chain compounds Ca3Co2-xFexO6 (x = 0, 0.1, 0.2 and 0.4). Rietveld refinement of neutron powder diffraction patterns at room temperature confirms the single-phase formation for all the compounds in rhombohedral structure with space group R3-barc. Rietveld refinement also confirms that Fe was doped at the trigonal prism site, 6a (0, 0, 1/4) of Co. The high temperature magnetic susceptibility obeys the Curie-Weiss law; the value of the paramagnetic Curie temperature (?p) decreases as the concentration of iron increases and it becomes negative for x = 0.4. No extra Bragg peak as well as no observable enhancement in the intensity of the fundamental (nuclear) Bragg peaks has been observed in the neutron diffraction patterns down to 30 K. No depolarization of neutron beam has been observed down to 3 K confirming the absence of ...
Systematic analysis of the energy level schemes, ground state absorption (GSA) and covalency effects for the Ni"2"+ ion in Ca_3Sc_2Ge_3O_1_2 was performed. The recently developed first-principles approach to the analysis of the absorption spectra of impurity ions in crystals based on the discrete variational multi-electron method (DV-ME) [K. Ogasawara et al., Phys. Rev. B 64, 115413 (2001)] was used in the calculations. As a result, complete energy level schemes of Ni"2"+ and its absorption spectra at both possible crystallographic positions (distorted octahedral Sc"3"+ and tetrahedral Ge"4"+ positions) were calculated, assigned and compared with experimental data. Energies of the charge transfer (CT) transitions for both positions are estimated. Numerical contributions of all possible electron configurations into the calculated energy states were determined. By performing analysis of the molecular orbitals (MO) population, it was shown that ...
Mesocarp tissue from sucrose-accumulating sweet melon (Cucumis melo cv. Galia) showed sucrose synthase activity (ca1 nkat/gfw) while soluble acid invertase and sucrose phosphate synthase activities were not observed. Sucrose uptake into mesocarp discs was linear with sucrose concentration (1-500 mM) and unaffected by PCMBS and CCCP. Sucrose compartmentation into the vacuole also increased linearly with sucrose concentration as indicated by compartmental efflux kinetics. Mesocarp discs incubated in /sup 14/C-fructose + UDP-glu synthesized /sup 14/C-sucrose and efflux kinetics indicated that the /sup 14/C-sucrose was compartmentalized. These data support the hypothesis that two mechanisms are involved in sucrose accumulation in sweet melon: (1) compartmentation of intact sucrose and (2) synthesis of sucrose via sucrose synthase and subsequent compartmentation in the vacuole.
This paper demonstrates a proof-of-concept approach for encapsulating the insulin and Fe3O4 nanoparticles into size-controllable alginate microcapsules utilizing the electrostatic droplets (ESD) technique. We have established that the combination of ESD and external gelation is quite effective in producing uniform-sized polymer particles. In addition, using the external gelation technique, the droplets containing a sodium-alginate were gelled in situ by immersion in Ca2+, Ba2+, or Cu2+ ions for a few minutes. The results show that different-type divalent cations caused various surface features to appear on the microcapsules (e.g., cracking, orange peel, pitting, splitting, wrinkling, etc.). The particle size can be adjusted from a few micrometers to ca. 1,000??m by electrostatic force. The...
Ethnopharmacological relevance: Tong Luo Jiu Nao (TLJN) is a modern Chinese formula based on Traditional Chinese Medicine theory that has been used to treat ischemic cerebral stroke and vascular dementia. TLJN belongs to the ethnopharmacological family of medicines. In this study, we investigated the mechanism of the TLJN effect on Alzheimer's disease (AD). Aim of the study: To investigate the effect of TLJN on b-amyloid-degrading enzymes and learning and memory in the AD rat brain. Materials and methods: AD rats whose disease was induced by Ab25-35 injection into the bilateral hippocampus CA1 region were subjected to intragastric administration of various preparations. The experimental animals were healthy male Sprague-Dawley rats which were randomly divided into normal, sham, model, TLJN...
The association between invasive and native species varies across spatial scales and is affected by phylogenetic relatedness, but these issues have rarely been addressed in aquatic ecosystems. In this study, we used a non-native, highly invasive species of Poaceae (tropical signalgrass) to test the hypotheses that (i) tropical signalgrass success correlates negatively with success of most native species of macrophytes at fine spatial scales, but its success correlates positively or at random with natives at coarse spatial scales, and that (ii) tropical signalgrass is less associated with native species belonging to the family Poaceae than with species belonging to other families (Darwin?s naturalization hypothesis). We used a dataset obtained at fine (0.25?m2) and coarse (ca. 1,000?m2) sca...
The atomic structures of calcium sialons Ca_xSi_1_2_-_mAl_mN_1_6 (m = 0.5, 1, 2, 4) with the #alpha#- or #beta#-Si_3N_4-type structure were calculated, using the ab initio DFT approach, including relaxations of both lattice parameters and positions of the atoms. For all m values the #alpha#-Si_3N_4-type structure has a lower energy than the #beta#-type. For m = 1, 2 and 4 the #alpha#-type structure is also stable against decomposition into the metal nitrides, in agreement with experimental data. For m = 0.5 stability becomes uncertain. Al ions prefer positions close to Ca. Rather strong structural relaxations occur around the Ca ion.
The grain boundary misorientation distribution of 203 grain boundaries in bulk processed high Tc superconductor YBa_2Cu_3O_7_-_#delta# with five processing conditions;, was studied. Two complementary analytical approaches, Grain Boundary Misorientation Distribution (GBMD) from the random description, using a hypothesis test and #chi#"2 analysis, and Grain Boundary Character Distribution (GBCD), using the Coincidence Site Lattice (CSL) model, were applied. The GBMD and GBCD both showed grain boundary evolution departing from a random distribution above 935 C processing temperature. The GBCD analyses indicated an approximately linear increase in the population of CSL-related boundaries, among which the tetragonal CSL (c/a #not =# 3) boundaries grew in the same trend while orthorhombic boundaries (c/a = 3) became stagnated. The results from comparing the corresponding GBCD and volume averaged J_c for each batch indicated that the tetragonal CSL boundaries were oxygen deficient and ...
Sr3In0.9Co1.1O6, isostructural to Ca3Co2O6, is revealed by the study of the phase relations in the system SrO-InO1.5-CoOx (1000 oC). The structure of Sr3In0.9Co1.1O6 is refined by the combination of powder X-ray and neutron diffraction. Sr3In0.9Co1.1O6 crystallizes in a trigonal lattice with the cell parameters a=b=9.59438(3) A, c=11.02172(4) A with the space group R-3c. Its structure possesses 1D (In/Co)O3 chains running along the c-axis constructed by alternating face-sharing CoO6 octahedra and (In0.9Co0.1)O6 trigonal prisms. The co-occupation of In3+ and Co3+ at the trigonal prismatic site is evidenced by elementary analysis and determined by the structure refinement. Sr3In0.9Co1.1O6 is paramagnetic, and the susceptibility is consistent with the occupation of Co3+ at 10% of the trigonal prismatic positions in a high spin state (HS, S=2). The HS Co3+ is well separated by diamagnetic CoO6 octahedra and InO6 trigonal prisms and shows a g factor ...
The energy E(c/a) for a bcc element stretched along its [001] axis (the Bain path) has a minimum at c/a=1, a maximum at c/a=#sq root#(2), and an elastically unstable local minimum at c/a>#sq root#(2). An alternative path connecting the bcc and fcc structures is the rhombohedral lattice. The primitive lattice has R3m symmetry, with the angle #alpha# changing from 109.4 deg. (bcc), to 90 deg. (simple cubic), to 60 deg. (fcc). We study this path for the non-magnetic bcc transition metals (V, Nb, Mo, Ta, and W) using both all-electron linearized augmented plane wave and projector augmented wave VASP codes. Except for Ta, the energy E(#alpha#) has a local maximum at #alpha#=60 deg., with local minima near 55 deg. and 70 deg., the latter having lower energy, suggesting the possibility of a metastable rhombohedral state for these materials. We first examine the elastic stability of the 70 deg. minimum structure, and determine that only W is elastically stable in this structure, with the ...
The results of investigation into a new series of Z-even nuclei - precursors of delayed protons (PDP) -"6"5Ge, "8"9Se, "9"3Kr, "8"1Zr, and "8"5Mo are presented. PDP were obtained by irradiation of targets in the following reactions: Zn(He, 2n) "6"5Ge, 22 MeV; "4"0Ca("3"2S, 2 pn) "1"9Se, 100 MeV; "6"0Ni ("1"60, 3 n), "7"3Kr, 75 MeV; "5"2Cr ("3"2S, 3n)"8"1Zr, 110 MeV; "5"6Fe("3"2S, 3n)"8"5Mo, 120 MeV. The targets (self-sustaining foils of thickness approximately 1.2 mg/cm"2) were placed at an angle of 15 deg to the direction of the ion beam. Upon irradiation targets were moved downwards into a measuring position. The spectra of protons, X and gamma-rays, and also the spectra of p - x, p-#gamma#, x - #gamma# coincidences accompanying the decay of "6"5Ge, "6"9Se,"7"3Kr and "8"1Zr, and "8"5Mo were measured. The measured half-lives are equal, to 31.5+-1.9, 27.3+-0.5, 28.5+-1.1, 6.3+-0.5, and 5.6 +-0.9 s respectively. The experimental spectra are ...
The Chinese government has enacted policies to promote alternative vehicle fuels (AVFs) and alternative fuel vehicles (AFVs), including city bus fleets. The life cycle (LC), energy savings (ES) and GHG reduction (GR) profiles of AVFs/AFVs are critical to those policy decisions. The well-to-wheels module of the Tsinghua-CA3EM model is employed to investigate actual performance data. Compared with conventional buses, AFVs offer differences in performance in terms of both ES and GR. Only half of the AFVs analyzed demonstrate dual benefits. However, all non-oil/gas pathways can substitute oil/gas with coal. Current policies seek to promote technology improvements and market creation initiatives within the guiding framework of national-level diversification and district-level uniformity. Combined with their actual LC behavior and in keeping with near- and long-term strategies, integrated policies should seek to (1) apply hybrid electric technology ...
We have investigated the growth behaviors of high temperature compatible ZrO_2 insulation coatings on Ag and AgMg sheathed Bi_2Sr_2Ca_1Cu_2O_x superconducting tapes depending on number of dipping and thermal conditions. The coatings were fabricated on long-length superconducting tape substrates using a solution derived from Zr tetrabutoxide, solvent and chelating agent for high magnetic field magnets. The layer-on-layer growth behaviors were characterized by environmental scanning electron microscope (ESEM), energy dispersive spectroscopy (EDS), X-ray maps and X-ray diffraction (XRD). This research showed that the ZrO_2 coatings were regularly grown on Ag-based tape substrates and coating thickness increased with increasing number of dipping. It was found that ceramic oxides formed at temperature range 450 and 550 deg. C. The final coating thickness changed between 6 and 8 #mu#m after annealing process. Resistance of insulation measured from ...
Precambrian gneisses in the San Bernardino Mountains were first identified and described in the vicinity of Baldwin Lake by Guillou (1953). Five lithologic units mappable at 1:24,000 scale are recognized: biotite [+-] muscovite quartzofeldspathic gneiss, amphibolite, pyroxene metagabbro, augen gneiss, and biotite [+-] muscovite granitic gneiss. Baldwin gneiss with this L Baldwin Lake, the gneissic fabric is rotated toward the northwest, subparallel to the Doble fault. Along this fault, Baldwin gneiss is structurally underlain by overturned Paleozoic quartzite and marble (Zabriskie Quartzite and Carrara Formation). Regional relations suggest that the Doble fault is a northeast-directed basement thrust fault of pre-Late Cretaceous age, and may be contemporaneous with late Paleozoic deformation and metamorphism of Paleozoic rocks further west in the range. Field relations suggest that Baldwin gneiss in its type area largely retains Proterozoic fabrics and mineral assemblages, despite ...
After 3 years of construction the trial run of the heating power station HKW 2 ended in November 1997 on time. No extraordinary damage occured during construction, assembly or commissioning. The plant has been operating according to schedule since November 1997. A brief inspection carried out in the summer of 1998 in order to assess warranty claims showed no damage to any part except one valve. Experience shows that all aforementioned activities were necessary. The paper reports about success and negative experience. Certification according to DIN EN ISO 9000ff., however, affords to guarantee of high-quality construction. Builders of such plants therefore need to set up their own quality assurance centre and ensure its technical competence. If necessary,additional experts should be called in.Quality assurance costs for HKW 2 came to about 0.5-0.6 percent of total costs. In view of the success and long life of this investment these expenses are more than justified. (orig.) [German] Nach ...
This study focuses the granitoids of center-southern portion of Guyana Shield, southeastern Roraima, Brazil. The region is characterized by two tectonic-stratigraphic domains, named as Central Guyana (GCD) and Uatuma-Anaua (UAD) and located probably in the limits of geochronological provinces (e.g. Ventuari-Tapajos or Tapajos-Parima, Central Amazonian and Maroni-Itacaiunas or Transamazon). The aim this doctoral thesis is to provide new petrological and lithostratigraphic constraints on the granitoid rocks and contribute to a better understanding of the origin and geo dynamic evolution of Guyana Shield. The GCD is only locally studied near to the UAD boundary, and new geological data and two single zircon Pb-evaporation ages in mylonitic biotite granodiorite (1.89 Ga) and foliated hastingsite-biotite granite (1.72 Ga) are presented. These ages of the protholiths contrast with the lithostratigraphic picture in the other areas of Cd (1.96-1.93 Ga). Regional mapping, petrography, ...
The measuring series was performed from November 1991 through April 1992 in seven drinking-water conditioning plants of the Fichtel mountains area in the north-eastern part of Bavaria, and the results revealed as an annual average a dose of about 1 - 40 WLM. The area of interest is a drinking-water catchment area where the ground water and other water resources include waters particularly rich in radon content, which explains this relatively high dose range. This is why comprehensive, specific local and long-term mearurements were carried out in order to assess the occupational radiation dose in the drinking-water conditioning plants, taking as a model site the conditioning plant of the municipal utilities of Hof in Weissenstadt. These more specific measurements were performed by the Technical Inspectorates (TUeV) of Bavaria and Saxony and the isotope laboratory of Georg-August University of Goettingen in mid-April 1994 (Goettingen University, TUeV Saxonia and Bavaria) and from June ...
Purpose: Antitumor activity of the dichloroplatinum(II)-histamine complexes labeled with I-125 or I-131 was investigated in a transplantable murine adenocarcinoma (MA) model. Methods: The tumor model was obtained in C3H/W female mice after subcutaneous inoculation of the tumor cells derived from the mice bearing a mammary tumor of spontaneous origin. Antitumor activities of the platinum-histamine complexes were investigated in three independent experiments, which differed in applied doses of preparations (PtCl{sub 2}Hist, PtCl{sub 2}[{sup 125}I]Hist, PtCl{sub 2}[{sup 131}I]Hist, PtCl{sub 2}Hist/PtCl{sub 2}[{sup 125}I]Hist and PtCl{sub 2}Hist/PtCl{sub 2}[{sup 131}I]Hist), treatment schedules as well as stages of the disease progress in the animals used. Experiment 1 included long-term, multidose treatment with low single doses (treatment duration 31-32 days; 8-10 doses of ca. 0.25{center_dot}MTD{sub Pt} each). Experiment 2 included short-term, multidose treatment with higher single ...
It has been acknowledged that river morphology and hydrology have been intensively altered due to the anthropic demands in floodplain land use and management, flood protection, promotion of navigability or energy production. Rivers were transformed in water highways, having lost contact with their surrounding floodplain as well as the plethora of ecological processes and occupants once thriving in these ecotonal zones. The identification of this emerging threat of morphological and hydrological alteration on ecological integrity adds further complexity in the exploitation of hydrosystem resources. These resources are heavily coveted and guarded by different lobbies each having strategic views on future project development. Stakeholders may want to promote hydro-electricity, ecologists a natural reserve, communes may wish to have an increased flood protection and leisure promoters a nautical center. As a result, the proposition of a river development project is certain to face ...