bluuebunny/crossref_metadata_2025_split huggingface dataset:
In situ — High Temperature Mössbauer Spectroscopy of Iron Nitrides and Nitridoferrates
Authors: Ksenofontov V. , Reiman S. , Waldeck M. , Niewa R. , Kniep R. , Gütlich P. 
Published: September 2003

AbstractThe stoichiometric iron nitrides γ′‐Fe4N, ε‐Fe3N and ζ‐Fe2N were characterized by Mössbauer spectroscopy. The thermal decomposition of ε‐Fe3N was studied in‐situ by means of a specially developed Mössbauer furnace. We found ε‐Fe3N to γ′‐Fe4N and ε‐Fe3Nx (x ≥ 1.3) as decomposition products and determined the border of γ′/ε transformation at T ≅ 930 K. Mössbauer spectroscopy was applied to study in‐situ the thermal decomposition of the nitridometalate Li3[FeIIIN2] and the formation of Li2[(Li1‐xFeIx)N], the compound with the largest local magnetic field ever observed in an iron containing material. The kinetics of formation and the stability of Li2[(Li1‐xFeIx)N] was of particular interest in the present study.
An in‐situ Mössbauer Study of the Formation of Cementite, Fe3C
Authors: Kniep B. , Constantinescu A. , Niemeier D. , Becker K. D. 
Published: September 2003

AbstractThe formation of cementite, Fe3C, from thin iron foils has been studied at 550 and 650 °C by means of in‐situ Mössbauer spectroscopy. At 550 °C, the kinetics of the reaction have been determined from time‐resolved experiments performed at different carbon activities. The product formation follows a two‐step process exhibiting two different kinetic regimes. The slow initial stages of the reaction as well as its rapid final part can be described by an Avrami‐type kinetics with a characteristic parameter of n = 3/2.
On the Reactivity of Silver Electrodes in a Chlorine Radiofrequency Plasma — Plasma Oxidation vs. Thermal Oxidation
Authors: Vennekamp M. , Janek J. 
Published: September 2003

AbstractThe plasma‐electrochemical growth of an ion‐conducting film by the oxidation of a metal in an electronegative plasma is investigated and compared with results from thermal oxidation. As model system we studied the oxidation kinetics of silver electrodes in a Cl2 rf plasma. The electrochemical control of the reaction by external currents through the product layer using the plasma as a fluid electrode was achieved. Both potentiostatic and galvanostatic control of the reaction was applied. The morphology of the product layer and its temporal evolution was investigated using SEM. A formation of silver chloride surface patterns in the oxidation process takes place if a simple stability criterion is not fulfilled. Specific surface morphologies were found under different experimental conditions. The morphology of the product layer is influenced by the external electric current and the substrate temperature. The influence of the plasma phase on the thermodynamics and kinetics of the oxidation process is discussed. The role of excited plasma species, the electrical charging of the surface and radiation from the plasma are taken into account.
Charge Transfer and Chemical Hardness along a Substitution Path in Metastable Au‐Sb Alloys
Authors: Stückl A. Claudia , Rau Franz , Weihrich Richard 
Published: September 2003

AbstractIn the present study the synthesis of metastable alloys of the noble metal Au and the semimetal Sb is realized by using high pressure techniques. The influence of Au on bulk Sb is shown experimentally by stepwise substitution. In addition to the effect of the most electronegative noble metal on Pauling's scale in the binary Au‐Sb phases, some ternary compounds with In, Sn, As, and Te in addition to Au and Sb are discussed. The experiments are planned to obtain a better knowledge on the reasons for building up a simple cubic Sb partial lattice, and their crystallographic results are used to construct model structures for new electronic structure calculations from first principles on the metastable π‐phases. Using the LCAO‐COansatzand density‐functional methods, we study total energies, band structures, densities of states and charge transfer properties according to Bader's method by integrating zero flux surfaces. Finally, from electronic band structure analysis, the quantities “chemical potential” μ, and “chemical hardness”, η, are derived according to the original ideas ofPearsonandParrand are applied to solid state problems using special points of the Brillouin zones within a band structure approximation for the first time. The results are shown to support the experimental findings about the substitution path within the system Au‐Sb.
On Mercury(I) Oxo Compounds — Quasi‐Relativistic Computational and Experimental Studies
Authors: Wang S. G. , Qiu Y.X. , Neumann E. , Deiseroth H. J. , Schwarz W. H. Eugen 
Published: September 2003

AbstractAbout 60 molecular species composed of up to 10 mercury atoms and of oxygen atoms and/or of some other elements or groups (such as halogen, OH2, OH, H, alkali, NO3) have been investigated quantum chemically. Different density functional approaches and theab initioSCF‐MP2 method were applied, comparing different basis sets and different atomic core sizes. It is important not to treat the Hg 5s, p, d as inactive core shells, and to use sufficiently many polarization functions.The shape of the 〉O‐Hg‐Hg‐O〈 units is not favorable concerning the formation of lattices composed of HgI, O and OH only. Despite its bulkiness, the OHgHgO units can easily come into contact with each other and then disproportionate. This is prevented in the so‐called ternary M‐HgIoxides by the embedded oxometallate (oxoacidic) anions. Furthermore, the HgIand HgIIoxide bond energies are less favorable towards the stability of HgIoxo compounds, as compared to Hg halidic or oxoacidic compounds. Both points are not promising concerning the search for HgIoxides/hydroxides, although the preparation of such compounds, including spacer groups, by topochemical reactions can still not be excluded.So far, experimental efforts towards the synthesis of such a new class of compounds have only demonstrated that HgIIis strictly preferred over HgIin the formation of solids of binary Hg‐O or ternary A‐Hg‐O composition (A = electropositive metal such as alkali, in contrast to M = transition or semi‐metal). This is so even if compounds containing ‘electron rich Hgδ—atoms’ (i.e. A‐Hg amalgams) are oxidized under mild conditions.
Development of a Novel Closed Loop UHV‐Apparatus for Coulometric Titrations of Oxygen by Means of λ‐Probes in Three‐Electrode‐Arrangement
Authors: Keller Hans‐Lothar , Wilk Peter 
Published: September 2003

AbstractA novel apparatus is described that does not only allow a very wide range of oxygen concentrations to be tuned in and gauged but also facilitates a direct observation of ongoing reactions within. It is principally built up of tubular lambda‐probes made of yttria stabilized zirconia (YSZ) and resembles a closed loop installation, enabling a total control of the inside atmosphere. Long term reactions inside the installation may be observed optically. First results of observed reactions are shown.
Kinetics of Oxidation Processes in the System Co/Ga studied by in situ X‐Ray Diffraction
Authors: Koops Ulrich , Martin Manfred 
Published: September 2003

AbstractOxidation processes in the system Co/Ga were studied by in situ X‐ray diffraction at temperatures between 800 and 1000 °C. Experiments were performed with metal powders and planar substrates. Oxidation of cobalt‐rich alloys, Co1‐xGax, results in the formation of mixtures of cobalt‐ and gallium‐containing oxides. During oxidation of the intermetallic compounds CoGa and CoGa3 only gallium is oxidized, and dense tarnishing layers of β‐Ga2O3 are formed. In all cases the oxide products are only intermediate products on the way to thermodynamic equilibrium, i.e. total oxidation of both metals. The kinetics during oxidation of the intermetallic compound CoGa was studied in detail by time resolved in situ X‐ray diffraction. After an induction time the kinetics can be described by a parabolic rate law with an activation energy of 312 kJ mol—1. From the decrease of the parabolic rate constant with decreasing oxygen partial pressure and the observation of pore formation at the metal‐oxide interface it can be concluded that (i) outward diffusion of Ga‐ions through β‐Ga2O3 is the rate determining step during this solid state reaction, and (ii) Ga‐ions are mobile by means of gallium vacancies.
Reactivity of Ammonium Halides: Action of Ammonium Chloride and Bromide on Iron and Iron(III) Chloride and Bromide
Authors: Bremm Stephan , Meyer Gerd 
Published: September 2003

AbstractAmmonium chloride and bromide, (NH4)Cl and (NH4)Br, act on elemental iron producing divalent iron in [Fe(NH3)2]Cl2 and [Fe(NH3)2]Br2, respectively, as single crystals at temperatures around 450 °C. Iron(III) chloride and bromide, FeCl3 and FeBr3, react with (NH4)Cl and (NH4)Br producing the erythrosiderites (NH4)2[Fe(NH3)Cl5] and (NH4)2[Fe(NH3)Br5], respectively, at fairly low temperatures (350 °C). At higher temperatures, 400 °C, iron(III) in (NH4)2[Fe(NH3)Cl5] is reduced to iron(II) forming (NH4)FeCl3 and, further, [Fe(NH3)2]Cl2 in an ammonia atmosphere. The reaction (NH4)Br + Fe (4:1) leads at 500 °C to the unexpected hitherto unknown [Fe(NH3)6]3[Fe8Br14], a mixed‐valent FeII/FeI compound. Thermal analysis under ammonia and the conditions of DTA/TG and powder X‐ray diffractometry shows that, for example, FeCl2 reacts with ammonia yielding in a strongly exothermic reaction [Fe(NH3)6]Cl2 that at higher temperatures produces [Fe(NH3)]Cl2, FeCl2 and, finally, Fe3N.
Preparing for community violence: Mood and behavioral correlates of the second Rodney King verdicts
Authors: Swendsen Joel David , Norman Sloan 
Published: September 2003

AbstractThis prospective investigation applied the Experience Sampling Method to examine the mood and behavioral responses of individuals facing the risk of community violence (in anticipation of the second Rodney King verdicts). Threatened participants experienced more negative affect and were less stable in behavioral involvement than individuals not under threat. Threatened participants also avoided social contact except for well‐known individuals, and were more likely to be traveling than nonthreatened participants. Social contact with family or close friends and being at home (one's own home or the home of familiar individuals) were associated with large reductions in negative affect for those at risk for urban violence. The findings are discussed in terms of risk factors for trauma following community‐wide stressors.
Correlates of psychological distress following armed robbery
Authors: Harrison Christine A. , Kinner Stuart A. 
Published: September 2003

AbstractAlthough mental health professionals have long been aware of the impact of traumatic events, it was not until 1980 that the term posttraumatic stress disorder (PTSD) was introduced into the DSM‐III. Since then, one major goal of research has been to identify factors associated with distress following trauma; as yet, few reliable indicators have emerged. Within the population of armed robbery victims, this is particularly true. The purpose of this study was to investigate possible correlates of posttrauma distress in armed robbery victims, and to assess the overall level of distress within this group. A questionnaire was mailed out to 57 robbery victims, aged 15 to 65, who were recruited as study volunteers via community outreach. Severity of the trauma, vulnerability attributions, and avoidant coping were significantly related to distress level, and victims exhibited a high level of distress.
The quality of the intimate relationships of male Vietnam veterans: Problems associated with posttraumatic stress disorder
Authors: Riggs David S. , Byrne Christina A. , Weathers Frank W. , Litz Brett T. 
Published: September 2003

AbstractThis study examined the quality of the intimate relationships of male Vietnam veterans. Heterosexual couples in which the veteran had posttraumatic stress disorder (PTSD; n = 26) were compared to couples in which the veteran did not have PTSD (n = 24). Over 70% of the PTSD veterans and their partners reported clinically significant levels of relationship distress compared to only about 30% of the non‐PTSD couples. Relationship difficulties appeared to encompass a wide range of areas, with PTSD veterans and their partners reporting that they had more problems in their relationships, more difficulties with intimacy, and had taken more steps toward separation and divorce than the non‐PTSD veterans and their partners. The degree of relationship distress was correlated with the severity of veterans' PTSD symptoms, particularly symptoms of emotional numbing. Research and clinical implications of the results are discussed.
Female partners' estimations of male veterans' combat‐related PTSD severity
Authors: Gallagher James G. , Riggs David S. , Byrne Christina A. , Weathers Frank W. 
Published: September 2003

AbstractThis study investigated concordance between male Vietnam veterans' and their female partners' reports of veterans' posttraumatic stress disorder (PTSD) symptoms. Fifty male Vietnam combat veterans and their partners rated the severity of their own PTSD symptoms. Also, partners rated the severity of veterans' symptoms. Results indicated modest levels of agreement in reports of symptom presence/absence. Partner ratings of veterans' PTSD severity were positively correlated with veteran reports and partners' own self‐reported PTSD symptoms. After controlling for veterans' self‐reported symptoms, partners' symptoms significantly predicted their estimates of veterans' avoidance symptoms, but not veterans' reexperiencing or hyperarousal symptoms. Theoretical and practical implications of these findings are discussed.
Responses to civilian war experiences: Predictors of psychological functioning and coping
Authors: Michultka Denise , Blanchard Edward B. , Kalous Tom 
Published: September 2003

AbstractThis study investigated civilian war trauma in Central American refugees, focusing on the diagnosis of posttraumatic stress disorder (PTSD) as related to war experience and demographic characteristics. Sixty eight percent of the refugees met the diagnostic criteria for PTSD. Diagnosis was best predicted by number of war experiences, severity of war trauma and level of anxiety/depression. Higher numbers of war experiences predicted PTSD severity, as did involvement in the legalization process, parenthood, and being a citizen of EI Salvador. In examining the PTSD symptom cluster scores, it was found that number of war experiences was a significant predictor in all clusters. These results are helpful in increasing our knowledge about the role of war experiences in civilian PTSD and the unique situation of the Central American refugees.
Suicidal behavior after severe trauma. Part 2: The association between methods of torture and of suicidal ideation in posttraumatic stress disotrder
Authors: Ferrada‐Noli Marcello , Asberg Marie , Ormstad Kari 
Published: September 2003

AbstractThe study reports on 65 refugees with diagnoses of posttraumatic stress disorder (PTSD) and manifest suicidal behavior (40% had suicide attempts; 29% detailed suicide plan; 31% recurrent suicidal thoughts). Our hypothesis was that the predominant kind of stressful experience in PTSD patients might be reflected in their choice of method when pondering or attempting suicide. Relationships were found to exist between the main stressors and the respective subjects' preference for suicide method. Particularly among PTSD patients with a history of torture, an association was found between the torture methods that the victim had been exposed to, and the suicide method used in ideation or attempts. Blunt force applied to the head and body was associated with jumping from a height or in front of trains, water torture with drowning, or sharp force torture with methods involving self‐inflicted stabbing or cutting. Relationships between main stressors and content of suicidal ideation are discussed.
Relationship between trauma narratives and trauma pathology
Authors: Amir Nader , Stafford Jane , Freshman Melinda S. , Foa Edna B. 
Published: September 2003

AbstractIn this study we examined the relationship between posttrauma pathology and the level of articulation (complexity) in rape narratives recounted by victims shortly after the assault. Degree of articulation was operationalized as the reading level of the narratives as determined by a computer program. Shortly after the trauma, reading level was correlated with severity of anxiety but not with posttraumatic stress disorder (PTSD) symptoms. Degree of the narrative articulation shortly after the trauma, however, was related to severity of later PTSD. These results are consistent with the hypothesis that the less developed trauma narratives hinder recovery from trauma.
Heart rate and blood pressure resting levels and responses to generic stressors in Vietnam veterans with posttraumatic stress disorder
Authors: Orr Scott P. , Meyerhoff James L. , Edwards Joely V. , Pitman Roger K. 
Published: September 2003

AbstractResting heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were measured on 3 successive mornings in the homes of drug‐free Vietnam combat veterans, classified on the basis of DSM‐III‐R criteria into current posttraumatic stress disorder (PTSD; n = 20) or non‐PTSD (n = 15). Responses to three generic stressor challenges (orthostatic, mental arithmetic, and cold pressor) were also measured. In the orthostatic stressor condition, DBP increased over time in the non‐PTSD, but not in the PTSD, veterans, suggesting a paradoxically reduced autonomic response in PTSD. There were no other significant group differences in resting levels or responses to any of the challenges for any measure.
Convergent validity of three posttraumatic symptoms inventories among adult sexual abuse survivors
Authors: Gold Jeffrey W. , Cardeña Etzel 
Published: September 2003

AbstractWe examined the convergent validity of three posttraumatic symptoms inventories, the civilian version of the Mississippi Scale for Combat‐Related PTSD (CM‐PTSD), the Trauma Symptom Checklist‐40 (TSC‐40), and the Response to Childhood Incest Questionnaire (RCIQ), in a sample of 52 adult sexual abuse survivors. The significant and moderate to strong correlations (r = .6 or higher) among these inventories supported their convergent validity. Comparison with other studies also suggests that these instruments can adequately discriminate clinical from nonclinical populations.
“Forward psychiatry” in the military: Its origins and effectiveness
Authors: Jones Edgar , Wessely Simon 
Published: September 2003

Abstract“Forward psychiatry” was devised in World War I for the treatment of shell shock and today is the standard intervention for combat stress reaction. It relied on three principles: proximity to battle, immediacy, and expectation of recovery, subsequently given the acronym “PIE”. Both US and UK forces belatedly reintroduced PIE methods during World War II to return servicemen to active duty and made confident claims for its efficacy. Advanced treatment units also appeared to have minimized psychiatric battle casualties during Korean and Vietnamese Wars. Evaluations of its use by Israeli forces in the Lebanon conflict showed higher return‐to‐duty rates than at base hospitals. A reexamination of these examples suggests that reported outcomes tended to exaggerate its effectiveness both as a treatment for acute stress reaction and as a prophylaxis for chronic disorders such as PTSD. It remains uncertain who is being served by the intervention: whether it is the individual soldier or the needs of the military.
Treatment of carnitine deficiency
Authors: Winter S. C. 
Published: September 2003

AbstractSummary: Carnitine deficiency is a secondary complication of many inborn errors of metabolism. Pharmacological treatment with carnitine not only corrects the deficiency, it facilitates removal of accumulating toxic acyl intermediates and the generation of mitochondrial free coenzyme A (CoA). The United States Food and Drug Administration (US FDA) approved the use of carnitine for the treatment of inborn errors of metabolism in 1992. This approval was based on retrospective chart analysis of 90 patients, with 18 in the untreated cohort and 72 in the treated cohort. Efficacy was evaluated on the basis of clinical and biochemical findings. Compelling data included increased excretion of disease‐specific acylcarnitine derivatives in a dose–response relationship, decreased levels of metabolites in the blood, and improved clinical status with decreased hospitalization frequency, improved growth and significantly lower mortality rates as compared to historical controls. Complications of carnitine treatment were few, with gastrointestinal disturbances and odour being the most frequent. No laboratory or clinical safety issues were identified. Intravenous carnitine preparations were also approved for treatment of secondary carnitine deficiency. Since only 25% of enteral carnitine is absorbed and gastrointestinal tolerance of high doses is poor, parenteral carnitine treatment is an appealing alternative therapeutic approach. In 7 patients treated long term with high‐dose weekly to daily venous boluses of parenteral carnitine through a subcutaneous venous port, benefits included decreased frequency of decompensations, improved growth, improved muscle strength and decreased reliance on medical foods with liberalization of protein intake. Port infections were the most troubling complication. Theoretical concerns continue to be voiced that carnitine might result in fatal arrhythmias in patients with long‐chain fat metabolism defects. No published clinical studies substantiate these concerns. Carnitine treatment of inborn errors of metabolism is a safe and integral part of the treatment regime for these disorders.
Mitochondrial oxidative phosphorylation: Pitfalls and tips in measuring and interpreting enzyme activities
Authors: Chretien D. , Rustin P. 
Published: September 2003

AbstractSummary: Mitochondrial oxidative phosphorylation (OXPHOS) is fundamental in all aspects of cellular life in aerobic cells and organisms. It is therefore not surprising that a variety of diseases have been attributed to dysfunction of the OXPHOS enzymes. Assessment of OXPHOS in human samples has proved to be a difficult task over years, even when relying on well‐established methods. The complexity and the flexibility of the mitochondrial organization in cells account for a large part in the difficulties encountered in assessing OXPHOS activity. Nevertheless, a careful and detailed analysis of OXPHOS enzyme activity in cells or biopsy samples from patients at risk provides ↑ diagnosis of potential OXPHOS deficiency. Problems inherent in the use of human material, mostly the small size of the samples to be analysed, are difficult to resolve. However, cautious handling of these samples permits reasonable confidence to be reached in the interpretation of the data.