bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of L‐arginine on the brain ischaemia‐reperfusion damage in rats: An investigation by somatosensory evoked potentials and histopathology
Authors: Kurt Tülay , Oğuzhanoğlu Atilla , Ortaç Ragıp , Turman Bülent , Adıgüzel Esat 
Published: December 2002

AbstractWe investigated whether administration of L‐arginine reduces the ischaemia‐reperfusion damage in the rat brain. The effects of L‐arginine were evaluated by means of somatosensory evoked potential (SEP) measurements and quantitative histopathological investigations. There was no significant difference between groups based on SEP data. The results obtained from quantitative histopathological investigations indicate that the nitric oxide (NO) precursor L‐arginine does not appear to have a protective effect on the brain ischaemia‐reperfusion damage. Furthermore, histopathological evaluation revealed a higher number of damaged cells in the L‐arginine treated rats than in control group. The results of the present study suggest that high concentrations of L‐arginine present in later stages of reperfusion might have harmful effects on reperfusion damage in the brain.
Design and Experimental Characterization of Low‐Volume PM10/2.5/1.0 Trichotomous Sampler Inlet
Authors: Kim Hyun T. , Lee Ken W. , Lee Seung J. 
Published: December 2002

AbstractThis paper presents the development and laboratory evaluation of a PM10/2.5/1.0 trichotomous sampling inlet that consists of two main parts: a previously designed PM10 size‐selective inlet part and a PM2.5/1.0 two‐stage virtual impactor, which was newly fabricated and attached serially to the PM10 size selective inlet part. Particles are collected in three locations through the trichotomous sampling inlet to provide for not only particle concentration measurements of PM10, PM2.5 and PM1.0, but also those of PM2.5–10 and PM1.0–2.5.
Instrumentation for Simultaneous Gas and Particle Velocity Measurements at Mach 5
Authors: Micheli Francis , Losfeld Gilles , Pérotto Myriam , Soulevant Didier 
Published: December 2002

AbstractThis study deals with re‐entry vehicles passing through high‐altitude clouds of ice particles. The particles disturb the flow field and are erosive, thereby increasing the turbulent heat flux considerably. Measurements were performed in a blow‐down wind tunnel to analyze the effects of a particle field on the flow. The wind tunnel flow was seeded by two aerosols. The first was used for LDV flow velocity measurements. Its size was checked by the analysis of its passage through a plane shock wave. The second aerosol was made of uniform micro‐spheres of 200 μm diameter, used to simulated the water droplets. The velocity, feeding and scattering of the latter aerosol need to be accurately measured. The velocities of the flow field and of the micro‐spheres were measured simultaneously by laser velocimetry. This paper describes the instruments used to seed, ascertain and measure this flow with two aerosols.
Determination of the Breakage and Wetting Parameters of Calcite and Their Correlations
Authors: Yekeler Meftuni , Ozkan Alper 
Published: December 2002

AbstractThis paper presents the breakage and wetting parameters of calcite mineral obtained experimentally and establishes a correlation between these characteristic parameters. The breakage parameter obtained from the different feed sizes of grinding is the specific rate of breakage (Si). The wettability parameter, obtained from surface chemistry‐based processes such as contact angle measurements or flotation methods, is the critical surface tension of wetting of a solid or mineral (γc). Calcite mineral, studied for the determination of the above parameters and their correlations, was ground in a laboratory‐size ceramic ball mill with dry, wet and chemically aided grindings and tested extensively to determine the γc values by using a contact angle goniometer and a newly designed micro‐column flotation cell. The highest Si value obtained was 0.35 min−1 for sodium dodecyl sulfate (SDDS)‐aided grinding, and the lowest Si value was 0.26 min−1 for dry grinding of the −600+425 feed in the mill. The γc values for calcite were obtained as 34.0–34.9 mN/m for SDDS‐treated calcite surfaces, 29.9–31.4 mN/m for sodium oleate‐treated surfaces and >72 mN/m for both dry and wet ground products whose surfaces were not treated chemically. Some correlations were established between the Si and γc parameters; as the Si increases, γc decreases, indicating that relatively more hydrophobic surfaces are broken faster for the largest sizes, resulting in higher Si values with more fines (lower γ of Bi, j) in the finer size distribution region (i.e. −150 μm).
Determination of the Refractive Index of Water‐dispersible Granules for Use in Laser Diffraction Experiments
Authors: Saveyn Hans , Mermuys Dries , Thas Olivier , van der Meeren Paul 
Published: December 2002

AbstractModern laser light scattering equipment can cover a very broad particle size range by using complex algorithms, such as the Mie theory. A disadvantage of this theory, however, is that it requires the knowledge of the refractive index of the particles, which is not straightforward for powdered organic substances. In this study, thiram, a common dithiocarbamate fungicide, was used as a model compound. In a first part, a method was elaborated to determine the refractive index, based on refractive index measurements of solutions of the compound of interest in a range of solvents. Two different extrapolation techniques were compared. Both techniques were validated by applying them to the determination of the refractive indices of poly(vinyl acetate) and poly(methyl methacrylate). Secondly, the influence of the refractive index value on the generated particle size distribution in the laser diffraction software was investigated. It was observed that widely different particle size distributions can be generated by the laser diffraction software for a single experimental data‐set. Therefore, accurate refractive index information is required to obtain reliable particle size distribution results.
Ab Initio Study on Interactions in Difluoroamine Clusters from one to four Molecules
Authors: Ju Xue‐Hai , Xiao He‐Ming 
Published: December 2002

AbstractAb initio calculations at HF, MP2 levels of theory with 6‐311G* basis set in combination with counterpoise procedure for BSSE correction have been performed on difluoroamine clusters consisting of up to four molecules. The dimer, trimer and tetramer were all found to exhibit two minima. There are two types of clusters: cyclic and chain. The corrected bond energies are 9.19, 19.22 and 33.67 kJ/mol at the MP2/6‐311G*//HF/6‐311G* level for the more stable dimer, trimer and tetramer, respectively. The contribution of cooperative effect to the interaction energy is quite significant in the cyclic clusters, but negligible in the chain ones. There exist H‐bonds which involve six and eight F⋅⋅⋅H contacts at ca. 0.23–0.24 nm in cyclic trimer and cyclic tetramer, respectively. The intermolecular interaction is an exothermic process under 400.0 K accompanied by a decrease in the probability of complex formation, and the interactions become weak as temperature increases.
Metal‐Fluorocarbon‐Pyrolants IV: Thermochemical and Combustion Behaviour of Magnesium/Teflon/Viton (MTV)
Authors: Koch Ernst‐Christian 
Published: December 2002

AbstractThe thermochemical and combustion behaviour of pyrotechnic payloads based on magnesium, Teflon® and Viton®, so‐called MTV is discussed. Thermochemical and FTIR‐spectroscopic analysis of magnesium/Teflon® combustion residues indicates the intermediate formation of a Grignard‐type CMgF compound in the condensed phase as part of a preignition reaction (PIR). The PIR is mainly responsible for the observed burning rate which rises exponentially with rising magnesium weight fractions from ξ(Mg)∼0.2 to ξ(Mg)∼0.70 and declines at ξ(Mg)>∼0.70. A tentative mechanism for the combustion process is presented.
A Simple Relation between the Detonation Velocity of an Explosive and its Gurney Energy
Authors: Koch André , Arnold Niklaus , Estermann Markus 
Published: December 2002

AbstractBased on energetic considerations, we deduce a simple link between the detonation velocity D of an explosive and its Gurney energy EG, namely $\rm{ \sqrt {2E_G } = D/3.08}$. The calculations rely on classical results of detonation theory, linked to the assumption of adiabatic expansion of the gaseous detonation products.
Phase transitions and amorphization of CaWO4 at high pressure
Authors: Errandonea Daniel , Somayazulu Maddury , Häusermann Daniel 
Published: December 2002

AbstractThe structural phase transitions in CaWO4 were studied by in situ energy‐dispersive X‐ray diffraction in a diamond‐anvil‐cell under high pressure up to 65 GPa at room temperature. The previously reported phase transition detected by Raman spectroscopy at 10 GPa was observed in our experiments at 12 GPa and the high‐pressure phase was characterized. This transition is from the tetragonal scheelite structure (I41/a) of CaWO4 to a monoclinic wolframite‐type structure (P2/c) and a small discontinuity in the evolution of the unit‐cell volume was detectable during the transformation (ΔV/V < –1.9%). In addition, we observed that CaWO4 becomes amorphous at pressures exceeding 40 GPa and found that a novel high‐pressure phase of CaWO4 can be obtained at 45 GPa after heating to 477 K and quenching to room temperature an amorphous sample.
Optical identification of impurity levels in strongly phosphorus‐doped wide‐gap II–VI bulk semimagnetic semiconductors
Authors: Van Khoi Le , Kossut J. , Gałazka R.R. 
Published: December 2002

AbstractZn1–xMnxTe and Cd1–xMnxTe crystals doped with phosphorus have been investigated by means of the measurement of Hall effect, photoluminescence and reflectance. By annealing under high pressure of nitrogen (up to 4 MPa) at T = 800 °C for a week, a free hole density as high as 5 × 1018 cm–3 was achieved in Zn0.95Mn0.05Te, while in Cd0.99Mn0.01Te it was only 8 × 1016 cm–3. The phosphorus acceptor binding energy in Zn0.975Mn0.025Te and Cd0.99Mn0.01Te was found to be (0.036 ± 0.002) eV and (0.054 ± 0.002) eV, respectively.
Double thermal donors in Czochralski‐grown silicon heat‐treated under atmospheric and high hydrostatic pressures
Authors: Emtsev V. V. , Ammerlaan C. A. J. , Emtsev V. V. , Oganesyan G. A. , Andreev B. A. , Kuritsyn D. I. , Misiuk A. , Surma B. , Londos C. A. 
Published: December 2002

AbstractThe formation kinetics of Thermal Double Donors, a dominant family of thermal donors in Czochralski‐grown silicon annealed at T < 600 °C, is studied in detail. A striking enhancement effect of hydrostatic pressures of about 1 GPa on their formation processes, even in a temperature region of thermal instability of these donor centers at about T = 600 °C under normal conditions, is clearly demonstrated. The experimental data obtained in the present work are in agreement with the recent theoretical calculations of oxygen diffusion and agglomeration processes in heat‐treated Si.
Selective magneto‐luminescence spectroscopy of donoacceptor pairs in n‐GaAs
Authors: Wysmolek A. 
Published: December 2002

AbstractThe results of selective magneto‐luminescence measurements of donoacceptor pairs in n‐type GaAs are discussed. The experimental data are compared with the calculated energy levels of a hydrogen‐like atom in a magnetic field, enabling us to identify a large number of high angular momentum states of the hydrogen‐like impurity in magnetic fields. It is shown that in addition to intra‐donor transitions, the spin‐flip excitations of donor–acceptor pairs involving heavy and light holes can be observed, yielding information about g‐factors for heavy and light holes. For the pairs with separations smaller than the donor Bohr radius, a strong modification of the SPL spectrum is observed. This effect is discussed in terms of modification of the acceptor ground state induced by the interaction with a neighbouring donor centre.
Hydrogen passivation of the SiGa donor in GaP
Authors: Ulrici W. , Clerjaud B. , Côte D. 
Published: December 2002

AbstractIn LEC‐grown GaP doped with silicon, two vibrational absorption lines are measured at 2175.1 and 2190.3 cm–1 (T = 7 K). These lines are due to H stretching modes where hydrogen passivates SiGa donors. Uniaxial stress experiments show that the SiGa complex responsible for the 2175.1 cm–1 line has trigonal symmetry and is the isolated passivated SiGa. The complex creating the 2190.3 cm–1 line has the symmetry Cs and contains additionally a BGa with the four constituents located in an {110} mirror plane. Therefore, also the structure of the group‐IV donohydrogen complexes is in GaP different from that observed in GaAs.
Shallow donor activity of S–H, Se–H, and Te–H complexes in silicon
Authors: Coutinho J. , Torres V.J.B. , Jones R. , Resende A. , Briddon P.R. 
Published: December 2002

AbstractThe interaction of a single hydrogen atom with a substitutional chalcogen impurity (S, Se, or Te) is investigated by ab‐initio modeling. In Se–H and Te–H complexes, the proton sits at an anti‐bonding site relative to a nearest neighbor silicon atom, but two competitive trigonal structures for S–H are found. All the singly hydrogenated complexes are predicted to behave as shallow donors with levels lying above those of the substitutional S, Se and Te double donors. A comparison of our results with experimental data suggests an assignment of the Si‐NL60 EPR signal to Se–H.
Properties of zinc acceptor and exciton bound to zinc in ammonothermal GaN
Authors: Korona K. P. , Doradziński R. , Palczewska M. , Pietras M. , Kamińska M. , Kuhl J. 
Published: December 2002

AbstractTime‐resolved photoluminescence (TRPL) and electron paramagnetic resonance (EPR) studies of Zn acceptor in GaN are presented. The EPR measurements revealed a strong line, which was ascribed to either an isolated Zn acceptor or to a complex defect involving Zn. Two photoluminescence lines were analyzed: the well‐known line of exciton bound to Mg acceptor, AMgX at 3.467 eV (8 K), and a new line that was ascribed to exciton bound to Zn acceptor, AZnX at 3.456 eV. The radiative decay time of the AZnX was about 1.4 ns, which was longer than that of the AMgX line. The longer radiative lifetime suggested a smaller radius of the AZnX wave function.
Therapeutic community treatment of personality disorder: service use and mortality over 3 years' follow-up
Authors: Davies Steffan , Campling Penelope 
Published: December 2002

BackgroundA number of studies have demonstrated reductions in the utilisation of psychiatric services, especially acute inpatient admissions, following therapeutic community treatment of personality disorder. These studies have, however, been of limited duration (1 year) and follow-up has not always been complete.AimsTo identify hospital admissions before and after therapeutic community treatment of personality disorder.MethodA naturalistic clinical cohort of patients admitted between January 1993 and December 1995 was followed up for 3 years. All subjects were traced to their current consultant psychiatrist, general practitioner or death.ResultsAll patients were traced at 3-year follow-up. The significant reduction in in-patient admissions seen in the first year was maintained over 3 years. Those with the poorest outcomes, suicide, accidental death or prolonged admission were all in the quartile with the shortest admissions (under 42 days) to the therapeutic community.ConclusionsPreviously reported reductions in psychiatric admissions following therapeutic community treatment of personality disorder are maintained over 3 years.
Carry on shrinking: career intentions and attitudes to psychiatry of prospective medical students
Authors: Maidment R. , Livingston G. , Katona M. , Whitaker E. , Katona C. 
Published: December 2002

Aims and MethodThere is a shortage of doctors in the UK, particularly in psychiatry and pathology. Little is known about prospective medical students' career intentions or attitudes. This study aimed to report on the career intentions and attitudes to psychiatry of 819 attenders at a sixth-form conference for prospective medical students.ResultsA much higher proportion of students expressed favourable attitudes to psychiatry as a career than might have been expected. The most popular career was paediatrics and the least popular was genitourinary medicine.IMPLICATIONSMedical schools need to be proactive in providing information, career advice and positive role models. This may counteract negative propaganda and encourage career choice in tune with students' earlier feelings and patients' needs.
A Family of Group 4 Metal Alkoxo Complexes with an M3(μ3‐O) Core Relevant to Ziegler–Natta Catalyst Intermediates
Authors: Utko Józef , Przybylak Szymon , Jerzykiewicz Lucjan B. , Szafert Sławomir , Sobota Piotr 
Published: December 2002

AbstractReactions of [Mg(thffo)2] (1) or [Ca(thffo)2] (2) with ZrCl4 or HfCl4 in a CH2Cl2/THF/CH3CN mixture give thermally stable neutral heterobimetallic tetranuclear complexes [M3M′(μx‐O)(μ,η2‐thffo)6(Cl)6] (thffo=tetrahydrofurfuroxide; M/M′/x: 3, Zr/Mg/3; 4, Hf/Mg/3; 5, Zr/Ca/4; 6, Hf/Ca/4) as colorless crystals in 75–82 % yield. X‐ray diffraction studies show complexes 3–5 to contain oxo‐bridged M3 triangles that are capped by an alkaline earth metal‐containing moiety to form species of C3 symmetry. Reactions of ZrCl4 and HfCl4 with pure tetrahydrofurfuryl alcohol in EtOH and MeOH provide ionic complexes [M3(μ3‐O)(μ,η2‐thffo)3(L)3(Cl)6]Cl (M/L: 8, Zr/EtOH; 9, Hf/EtOH; 10, Zr/MeOH) in 66–79 % yield. Complexes 8–10 consist of M3 triangles that are analogous to those in 3–6 and possess similar overall symmetry, as shown by X‐ray crystallography. Changes in the reaction conditions afforded the asymmetric neutral dimer [Zr2(μ‐thffo)2(thffoH)(Cl)6] (7) and the homometallic [Zr3(μ3‐O)(μ,η2‐thp)3(thf)2(Cl)7] (11).
Differential responses of intracisternal injection of interleukin‐1 β to acute and inflammatory orofacial pain model in freely moving rats
Authors: Choi Hyo S. , Park Jae S. , Ahn Dong K. 
Published: December 2002

AbstractThe present study was performed to investigate the modulatory role of certain interleukin (IL)‐1β in nociception with a nociceptive jaw opening reflex and an orofacial formalin test in freely moving rats. In an acute pain model, 10 pg, 100 pg and 1 ng IL‐1β injected intracisternally did not change the digastric eletromyogram (dEMG). However, 10 ng IL‐1β suppressed dEMG to 76±8 % of control values. In an inflammatory pain model, 10 pg IL‐1β injected intracisternally did not change formalin‐induced noxious behavioral responses. However, 100 pg IL‐1β increased formalin‐induced noxious behavioral responses. At higher dose of 10 ng IL‐1β, it did not increase formalin‐induced behavioral responses. Pretreatment with IL‐1 receptor antagonist abolished hyperalgesic response of 100 pg IL‐1β. These results suggest that the intracisternal injection of IL‐1β modulate the transmission of nociceptive information in the orofacial area. The hypo/hyper‐algesic responses of central cytokines seem to depend on the pain model or dose related manner and the hyperalgesic action seems to be mediated by IL‐1 receptor.
Transplantation of a new composite of neural cells and marrow stromal cells into rat brain after stroke
Authors: Li Yi , Yang Xiaoyi , Chen Jieli , Wang Lei , Wang Ying , Zhang Chunling , Chen Xiaoguang , Katakowski Mark , Mikkelsen Tom , Lu Mei , Chopp Michael 
Published: December 2002

AbstractWe constructed a biologic material composed of fetal rat brain cells (neurospheres) and adult rat bone marrow stromal cells (MSCs), designated as NMCspheres. Adult rats were subjected to 2 hours of middle cerebral artery occlusion (MCAo) and implanted with cultured prelabeled NMCspheres (n=6), neurospheres (n=5) or MSCs (n=6) into the ischemic penumbra at 24 hours after MCAo. Control adult rats (n=10) were subjected to MCAo alone. In vitro within the NMCspheres, MSCs rapidly formed a process network with intact neural cells compared with a necrotic core within neurospheres alone. An in vivo rat corneal assay demonstrated that NMCspheres enhanced angiogenesis compared to MSCs and neurospheres. Neurological functional recovery after stroke was enhanced in rats treated with NMCspheres, compared to rats with neurosphere or MSC treatments by day 7 and day 14 after transplantation. The NMCspheres are a new composite material that may be employed in the treatment of stroke.
Effects of low‐dose scopolamine on locomotor activity: No dissociation between cognitive and non‐effects
Authors: Poorheidari Gholamreza , Pratt Judith A. , Dehghani Nima 
Published: December 2002

AbstractAttempts have been made to dissociate the cognitive effects of scopolamine from its non‐cognitive effects. It has been suggested that low doses of scopolamine may induce memory impairment without inducing significant non‐cognitive effects. We therefore tested changes in locomotor activity (as a non‐cognitive effect) in rats treated with low‐dose scopolamine (which is believed to induce cognitive effects only).In this study, locomotor activity (as a non‐cognitive effect) induced by low doses of this drug was evaluated by using two methods and rat strains. In the first study (circular box method, an automated open‐field), scopolamine hydrobromide (HBr), scopolamine methylbromide (MeBr) or saline was injected subcutaneously into male Sprague‐Dawley rats. After 30 min, rats were put into an automated open‐field and locomotor activity was quantified by recording interruptions of infrared beams, with print‐outs every 2 min for 16 min. Locomotor activity was assessed by summing these recordings. In the second study (closed platform), scopolamine HBr or saline was injected intraperitoneally into male Long‐Evans rats. Twenty minutes later, the rats were placed in the center of a square‐shaped closed platform (with 3×3 divisions). Locomotor activity was defined as the sum of crossings (traversing of four paws of the rat from one area into another of nine) and rears, which were recorded every 5 min for 20 min.Results from the circular box study showed that scopolamine HBr produced a marked increase in locomotor activity whereas scopolamine MeBr produced a non‐significant decrease in locomotor activity. The closed platform data also demonstrated that scopolamine HBr increased locomotor activity significantly.These data show that scopolamine can induce non‐cognitive effects (such as increased locomotor activity), even at low doses. Our results also imply that the increase in locomotor activity is mediated centrally.
Resonant interaction of LO phonons with excited donor states in GaN
Authors: Wysmolek A. , Potemski M. , Stepniewski R. , Baranowski J. M. , Look D. C. , Lee S. K. , Han J. Y. 
Published: December 2002

AbstractMagneto‐luminescence experiments performed on a thick, freestanding GaN layer in magnetic fields up to 28 T are presented. The photoluminescence spectrum of this material shows narrow emission lines due to neutral donor‐bound excitons (D0X). In addition to the principal recombination channel of D0X in which the donor is left in its ground state, two‐electron satellites (TES) involving different excited donor states, as well as LO phonon replica of the principal and satellite transitions are observed. For the magnetic field range in which internal donor excitations are tuned into resonance with the LO phonon excitations, the intensity of TES is strongly enhanced. A clear resonant interaction between TES corresponding to the highly excited donor states (n > 4) and LO phonon replica of D0X is observed. The observed effect is discussed in terms of electron–phonon interaction.
Oxidative stress in inborn errors of metabolism: Lessons from glutathione deficiency
Authors: Ristoff E. , Larsson A. 
Published: December 2002

AbstractOxidative stress has been thought to be involved in the pathogenesis of several inborn errors of metabolism, such as mitochondrial enzyme deficiencies, G6PD deficiency, methylmalonic acidaemia and PKU. The possible role of oxidative stress in the pathogenesis of inborn errors of metabolism is discussed in the light of inborn errors in the metabolism of glutathione.