745 research outputs found
Importance of tetrahedral coordination for high-valent transition metal oxides: YCrO as a model system
We have investigated the electronic structure of the high oxidation state
material YCrO within the framework of the Zaanen-Sawatzky-Allen phase
diagram. While Cr-based compounds like SrCrO/CaCrO and CrO
can be classified as small-gap or metallic negative-charge-transfer systems, we
find using photoelectron spectroscopy that YCrO is a robust insulator
despite the fact that its Cr ions have an even higher formal valence state of
5+. We reveal using band structure calculations that the tetrahedral
coordination of the Cr ions in YCrO plays a decisive role, namely to
diminish the bonding of the Cr states with the top of the O valence
band. This finding not only explains why the charge-transfer energy remains
effectively positive and the material stable, but also opens up a new route to
create doped carriers with symmetries different from those of other
transition-metal ions.Comment: 6 pages, 6 figure
Virological response without CD4 recovery
The objective of antiretroviral therapy (ART) is to suppress viral replication so that immune restoration can occur. Failure of immune restoration is usually associated with poor virological suppression. In children a good immunological and clinical response to ART is often achieved despite incomplete viral suppression. However, we have recently managed a number of children in whom immune restoration did not occur despite excellent virological suppression. We present a case, discuss possible causes and speculate on the appropriate course of action. Southern African Journal of HIV Medicine Vol. 7 (3) 2006: pp. 45-4
Novel Method of Cell-Free In Vitro Synthesis of the Human Fibroblast Growth Factor 1 Gene
Recombinant DNA projects generally involve cell-based gene cloning. However, because template DNA is not always readily available, in vitro chemical synthesis of complete genes from DNA oligonucleotides is becoming the preferred method for cloning. This article describes a new, rapid procedure based on Taq polymerase for the precise assembly of DNA oligonucleotides to yield the complete human fibroblast growth factor 1 (FGF1) gene, which is 468 bp long and has a G+C content of 51.5%. The new method involved two steps: (1) the design of the DNA oligonucleotides to be assembled and (2) the assembly of multiple oligonucleotides by PCR to generate the whole FGF1 gene. The procedure lasted a total of only 2 days, compared with 2 weeks for the conventional procedure. This method of gene synthesis is expected to facilitate various kinds of complex genetic engineering projects that require rapid gene amplification, such as cell-free whole-DNA library construction, as well as the construction of new genes or genes that contain any mutation, restriction site, or DNA tag
The relationship of individual accountability with job stress and work deviant behavior among nurses
Background and aims: Individual accountability and its positive and negative effectiveness are the most challenges of organization subjects. The root of some medical staffs' behaviors and activities is individual accountability. So, the present paper was conducted with the aim of identifying the relationship between individual accountability with job stress and work deviant behavior with mediating role of personality trait of conscientiousness. Methods: In this descriptive-analytic study, 175 employee nurses of Ayatollah Kashani and Hajar hospitals were entered in this research in 2014. Data were collected using Hochwarter, Casta, Mackgor, Mulkr, Robinson and Bennett, and House and Rizzo standard questionnaires. The structural equations model was used to study the relationship between Latent variables and the measured ones in conceptual model. Results: The results indicated that there is a significant positive correlation between the perception of individual accountability and personality trait of conscientiousness (P 0.05 and r = - 0.26, r = - 0.36). Conclusion: According to the present theoretical and research foundations at hand, individual accountability directly affects job stress and work deviant behavior among employees, and on the basis of the findings of the present study conscientiousness bears a significant negative causal effect on job stress and work deviant behavior. It is concluded that conscientiousness decreases the negative causal and potential effect of accountability on stress and work deviant behavior
Experiences of obesity among Saudi Arabian women contemplating bariatric surgery: An interpretative phenomenological analysis
This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2013 The Authors.This study explored experiences of obesity, its perceived causes and motives for surgery, as described by seven Saudi women contemplating bariatric surgery. The women experienced cultural restrictions on their physical and social activities. Obesity embodied these restrictions, attracting stigma and moral failure. Traditional clothing, foods, hospitality norms and limited outdoor female activities were regarded as barriers to weight loss. Bariatric surgery was chosen to protect health and to access normative female roles. Some were encouraged by relatives who had undergone surgery. Opting for surgery reflected both participants’ sense of powerlessness to self-manage weight and the social acceptability, within their family context, of this biomedical approach
Electrochemical Determination of Trichloroacetic Acid using Platinum Electrode
The electrochemical reduction of Trichloroacetic acid (TCA) on a platinum electrode by cyclic and linear sweep voltammetry was described. The measurements were investigated under optimized conditions. The supporting electrolyte was 0.01 M sodiumnitrate solution (pH 6.0), scan rate 50mV\s and the reached detection and quantification limits was 4x10-6 mol l-1. The obtained result indicated linear increasing of the current with concentration of TCAA between lower and upper detection limits and excellent sensitivity towards TCAA reduction, which demonstrates the analytical utility of platinum electrode. Meanwhile, interference from other ions and substances were examined. The experimental results indicate that the method for the determination of TCAA samples is successful comparing with other methods or techniques
Treatment in Borderline Class III Malocclusion: Orthodontic Camouflage (Extraction) Versus Orthognathic Surgery
AIMS: To investigate the differences in morphological characteristics of borderline class III patients who had undergone camouflage orthodontic treatment or orthognathic surgery, and to compare the treatment effects between these two modalities. MATERIALS AND METHODS: Cephalograms of 25 patients (13 orthodontic, 12 surgical) with class III malocclusion were analyzed. All had a pretreatment ANB angle greater than -5 masculine. RESULTS: Using discriminant analysis, only Holdaway angle was selected to differentiate patients in the pretreatment stage. Seventy-two per cent patients were correctly classified. In the orthodontic group, reverse overjet was corrected by retraction of the lower incisors and downward and backward rotation of the mandible. The surgical group was corrected by setback of the lower anterior dentoalveolus and uprighting of the lower incisors. No difference was found in posttreatment soft tissue measurements between the two groups. CONCLUSIONS: Twelve degree for the Holdaway angle can be a guideline in determining the treatment modalities for borderline class III patients, but the preferences of operators and patients are also important. (2) Both therapeutic options should highlight changes in the lower dentoalveolus and lower incisors. (3) Both treatment modalities can achieve satisfactory improvements to the people.published_or_final_versio
Repair of a defect following the removal of an impacted maxillary canine by orthodontic tooth movement: a case report
This case report describes a 13-year-old boy with alveolar bony defect resulted from surgical removal of impacted upper canine transposed in the anterior region. The boy had a normal occlusion with malposition of upper central and lateral incisors. The treatment objectives were to align teeth, close spaces by mesial movement of the buccal segments in the upper jaw to repair bone loss. Fixed appliance with palatal root torque was used for the mesial movements, levelling, and alignment of teeth
Electron attachment properties of c-C₄F₈O in different environments
The electron attachment properties of octafluorotetrahydrofuran (c-C₄F₈O) are investigated using two complementary experimental setups. The attachment and ionization cross sections of c-C₄F₈O are measured using an electron beam experiment. The effective ionization rate coefficient, electron drift velocity and electron diffusion coefficient in c-C₄F₈O diluted to concentrations lower than 0.6% in the buffer gases N₂, CO₂ and Ar, are measured using a pulsed Townsend experiment. A kinetic model is proposed, which combines the results of the two experiments
Designing an Algorithm for Students Impact on Social Adaptive Behavior in Political Education Context
This study aimed to discuss the social adjustment behaviors of university students. The social adjustment behaviors of university students not only relate to their healthy development but also significantly affect social development., the ideological and political education model combines with the impact on social adaptation behaviors of university students. It optimizes the article algorithm design and creates a theoretical model in the field of social adaptation of university students. The articles limitation is that it was made with a sample of 966 subjects. The methodology involved statistical analysis of students social adaptation status, understanding the average and standard deviation of each dimension and the basic situation of their social adaptation. The average social adjustment index of university students was found to be m=3.68. Changes were observed in the interpersonal relationships of university students in all dimensions of adaptation to the future, learning adaptation, psychological adaptation, and environmental adaptation before and after graduation. In conclusion, this article depends on the analysis of the current state of students adaptation to society, the main personal and environmental factors in the life of university students, and based on the results of analysis and research, provides recommendations for relevant improvements
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