Interface Microstructures and Bond Formation in Ultrasonic Consolidation

The quality of ultrasonically consolidated parts critically depends on the bond quality between individual metal foils. This necessitates a detailed understanding of interface microstructures and ultrasonic bonding mechanism. There is a lack of information on interface microstructures in ultrasonically consolidated parts as well as a lack of consensus on the mechanism of metal ultrasonic welding, especially on matters such as plastic deformation and recrystallization. In the current work, interface microstructures of an ultrasonically consolidated multi-material Al 3003-Ni 201 sample were analyzed in detail using optical microscopy, scanning electron microscopy, energy dispersive spectroscopy, and orientation imaging microscopy. Based on the results of microstructural studies, the mechanism of metal ultrasonic welding has been discussed. The reasons for formation of defects/unbonded regions in ultrasonically consolidated parts have also been identified and discussedMechanical Engineerin

The Emergence of Statutory Hygiene Precautions in the British Mining Industries, 1890-1914

It will be fifty years in 2008 since Oliver MacDonagh suggested that the adoption of new responsibilities by the state in the early nineteenth century was an inevitable response to the social consequences of the industrial revolution, and impervious to ideological and philosophical influences. This article revisits MacDonagh's model by examining the emergence of occupational health reform in the British mining industry in the early twentieth century. Until the introduction of statutory measures in 1905 to protect miners against developing silicosis and basic sanitation provisions to prevent cross-contamination of disease, state regulation of working conditions prioritized the prevention of accidental injuries. It is argued that this decisive shift in the scope and nature of government intervention can be understood as part of a process of institutional expansion of mining regulations that broadly parallels MacDonagh's model. Yet the precise details of when, and how, health reform emerged and the nature of these specific regulatory controls were influenced by a variety of factors, including visibility of risk, human agency, economic performance of the industry, and contemporary thinking in political economy

Chondrogenic potential of injectable κ-carrageenan hydrogel with encapsulated adipose stem cells for cartilage tissue-engineering applications

Due to the limited self-repair capacity of cartilage, regenerative medicine therapies for the treatment of cartilage defects must use a significant amount of cells, preferably applied using a hydrogel system that can promise their delivery and functionality at the specific site. This paper discusses the potential use of k-carrageenan hydrogels for the delivery of stem cells obt ained from adipose tissue in the treatment of cartilage tissue defects. The developed hydrogels were produced by an ionotropic gelation met hod and human adipose stem cells (hASCs) were encapsulated in 1.5% w/v k-carrageenan solution at a cell density of 5 10 6 cells/ml. The results from the analysis of the cell-encapsulating hydrogels, cultured for up to 21 days, indicated that k-carrageenan hydrogels support the viability, proliferation and chondrogenic differentiation of hASCs. Additionally, the mec hanical analysis demonstrated an increase in stiffness and viscoelastic properties of k-carrageenan gels with their encapsulated cells with increasing time in culture with chondrogenic medium. These results allowed the conclusion that k-carrageenan exhibits properties t hat enable the in vitro functionality of encapsulated hASCs and thus may provide the basis for new successful approaches for the treatment of cartilage defects.Elena G. Popa would like to acknowledge the Portuguese Foundation for Science and Technology (PhD Grant No. SFRH/BD/64070/2009)

Pregnancy, Microchimerism, and the Maternal Grandmother

A WOMAN OF REPRODUCTIVE AGE OFTEN HARBORS A SMALL NUMBER OF FOREIGN CELLS, REFERRED TO AS MICROCHIMERISM: a preexisting population of cells acquired during fetal life from her own mother, and newly acquired populations from her pregnancies. An intriguing question is whether the population of cells from her own mother can influence either maternal health during pregnancy and/or the next generation (grandchildren).Microchimerism from a woman's (i.e. proband's) own mother (mother-of-the-proband, MP) was studied in peripheral blood samples from women followed longitudinally during pregnancy who were confirmed to have uncomplicated obstetric outcomes. Women with preeclampsia were studied at the time of diagnosis and comparison made to women with healthy pregnancies matched for parity and gestational age. Participants and family members were HLA-genotyped for DRB1, DQA1, and DQB1 loci. An HLA polymorphism unique to the woman's mother was identified, and a panel of HLA-specific quantitative PCR assays was employed to identify and quantify microchimerism. Microchimerism from the MP was identified during normal, uncomplicated pregnancy, with a peak concentration in the third trimester. The likelihood of detection increased with advancing gestational age. For each advancing trimester, there was a 12.7-fold increase in the probability of detecting microchimerism relative to the prior trimester, 95% confidence intervals 3.2, 50.3, p<0.001. None of the women with preeclampsia, compared with 30% of matched healthy women, had microchimerism (p = 0.03).These results show that microchimerism from a woman's own mother is detectable in normal pregnancy and diminished in preeclampsia, supporting the previously unexplored hypothesis that MP microchimerism may be a marker reflecting healthy maternal adaptation to pregnancy

Cytokine preconditioning of engineered cartilage provides protection against interleukin-1 insult

Research reported in this publication was supported in part by the National Institute of Arthritis and Musculoskeletal and Skin Diseases and National Institute of Biomedical Imaging and Bioengineering of the National Institutes of Health under Award Number R01AR60361, R01AR061988, P41EB002520). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. ART was supported by a National Science Foundation Graduate Fellowship