Compatibility of deformation in two-phase Ti-Al alloys: Dependence on microstructure and orientation relationships

A two-phase alloy of composition Ti-47.5Al-2.5Cr has been studied under two heat-treated conditions in order to obtain different microstructures. These consisted of lamellar and equiaxed distributions of y grains in which the α₂ phase was distributed as long lamellae or smaller globules, respectively. The specific rotation relationships between γ/γ and γ/α₂ grains have been measured, and these have been used to understand their effect on the compatibility of deformation across adjacent grains. For this, detailed analysis of active slip systems has been carried out by transmission electron microscopy (TEM) observations of deformed samples. A theoretical calculation of a geometric compatibility factor characterizing the best slip transfer across adjacent grains has been used in such a way that it has been possible to deduce the role played by the type of orientation relationship between grains in producing active deformation systems that allow the maximum compatibility of deformation.     

The experiences of Sudanese unaccompanied minors in foster care.

Sudanese unaccompanied minors were separated from their parents in childhood and lived apart from their families in refugee camps for close to a decade before being resettled in the United States. This phenomenological study examines the refugees’ experiences of living in American foster families after living in peer groups in the camps. Interviews with 18 young adults, 7 years after resettlement, revealed that nearly all of the youth struggled with parental authority initially, and nearly half of them changed placements because of relationship difficulties with their foster parents. Misunderstandings based on cultural differences often exacerbated conflicts. However, 15 of 18 youth currently had a positive relationship with at least 1 foster parent, sometimes with a parent from their second or third placement. Changing foster families is often considered a failure in the child welfare system, but several Sudanese youth reported that having supportive relationships helped them during the acculturation process whether those relationships developed during the first or last placement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Involvement of the IP-10 chemokine in sarcoid granulomatous reactions

The accumulation of T cells and monocytes at sites of ongoing inflammation represents the earliest step in the series of events that lead to granuloma formation in sarcoidosis. In this study, we evaluated the pulmonary production of IFN-inducible protein 10 (IP-10), a CXC chemokine that stimulates the directional migration of activated T cells. Striking levels of IP-10 were demonstrated in the bronchoalveolar lavage (BAL) fluid of 24 patients with pulmonary sarcoidosis and lymphocytic alveolitis, as compared with patients with inactive disease or control subjects. A positive correlation was demonstrated between IP-10 levels and the number of sarcoid CD45R0+/CD4+ cells in the BAL. Immunochemistry, performed with an anti-human IP-10 polyclonal Ab in lymph nodes displaying prominent sarcoid granulomas, showed that cells bearing IP-10 were mainly epithelioid cells and CD68+ macrophages located inside granulomatous areas. Macrophages recovered from the BAL of sarcoid patients stained positive for IP-10 protein. Furthermore, alveolar macrophages isolated from sarcoid patients with T cell alveolitis and cultured for 24 h in presence of IFN-gamma secreted definite levels of IP-10 capable of inducing T cell chemiotaxis. Interestingly, alveolar lymphocytes recovered from patients with active sarcoidosis were CD4+ T cells expressing Th1 cytokines (IL-2 and IFN-gamma) and high levels of CXCR3. Taken together, these data suggest the potential role of IP-10 in regulating the migration and activation of T cells toward sites of sarcoid inflammatory process and the consequent granuloma formation.     

Formation and Characterization of Corrosion-Resistant Amorphous Coatings by Thermal Spraying*

Since it was first discovered that amorphous metals could be formed by rapid quenching from the liquid phase, these so-called metallic glasses have attracted an increasing amount of attention due to their unique properties. Forming amorphous metals by quenching from the liquid phase requires cooling rates on the order of 10⁵-10⁶ K/s. In order to achieve such cooling rates, one of the dimensions of the samples must be sufficiently small. For instance, a very thin ribbon enables amorphous alloys to be produced by the well known melt-spinning process. An alternative: approach is the use of thermal spraying to produce amorphous coatings. The first commercial product exploiting this approach was developed in 1984 and the subject has received increasing attention since this first development.

The purpose of the present work is to explore the conditions necessary for the formation of combustion flamesprayed amorphous coatings from NiMoFeB and NiCrFeSiB alloys. A technique based on differential thermal analysis has been developed to characterize and quantify the fraction of amorphous phase present in the partially amorphous coatings. It has been shown for the current two alloys that the amorphous content of coatings can be varied through control of the maximum substrate temperature, the initial powder condition and the powder size. These results will be compared to existing knowledge regarding the formation of amorphous alloys and, specifically, thermally-sprayed coatings.     

Altered alveolar macrophage function in calorie-restricted rats

The capacity of four chicken lines (Y11, L2, B13, PA12) to control Salmonella enteritidis (SE) phage type 4 (PT4) systemic colonization was investigated. Thirteen-week-old chickens were intravenously inoculated with 10(6) SE colony-forming units, and the levels of SE colonization were determined at various time intervals after inoculation in liver, spleen, genital organs, and ceca. The course of SE infection showed a rapid contamination of liver, spleen, and genital organs, whereas the ceca were infected later. A significant (P < 0.001) effect of the chicken line on levels of SE was detected on day 3 postinoculation (PI) in liver and ceca, on day 10 PI in ceca, and on day 15 PI in spleen. Because an early control of systemic Salmonella infection by the Ity/Nramp1 gene has been demonstrated in mice, we aimed to study the early resistance of chickens to SE. As a consequence, we then focused our study on the between- and within-line variabilities of SE levels on day 3 PI. According to the SE levels in liver on day 3 PI, the chicken lines could be classified as susceptible (Y11 and L2) or resistant (PA12 and B13). This early variability was explored in resistant B13 and susceptible L2 lines. Differences between these two lines were confirmed in liver but not in ceca. A large within-line variability was observed in all organs of these two lines. The genetic origin of this variability will have to be determined as a prerequisite to an eventual selection.     

Monocyte chemotactic protein expression in allergy and non-allergy-associated chronic sinusitis

The recently developed whole blood rapid assay for cardiac troponin T (TROP T) was evaluated by a cooperative study of general practitioners and office cardiologists in the Tokyo area (Tokyo TROP T Trial). Seventy patients with suspected acute myocardial infarction treated at 14 medical clinics were enrolled in this study. The diagnostic efficacy of troponin T was compared with that of electrocardiographic evaluations and clinical standards for diagnosis of acute myocardial infarction. Twelve of the 70 patients (17.1%) had final diagnoses of acute myocardial infarction or severe unstable angina necessitating emergency coronary intervention. Troponin T was judged as positive when simultaneously measured serum troponin T was more than 0.25 ng/ml. Sensitivity, specificity, positive predictive value, and negative predictive value were 100%, 58.6%, 33.3%, and 100% for electrocardiographic evaluation, and 58.3%, 100%, 100%, and 92.1% for troponin T, respectively. Presence of bundle branch block (11/70 cases) or previous myocardial infarction (14/70 cases) caused false positive readings on electrocardiography, and resulted in the lower positive predictive value. In contrast, troponin T was false in patients admitted within 4 hours after the onset, or patients with smaller infarct. The Tokyo TROP T Trial by general practitioners and office cardiologists concluded that the combination of electrocardiographic evaluation and use of troponin T is a rapid and efficient diagnostic method for the evaluation of patients with suspected acute myocardial infarction.