Microstructural characterization of AISI 431 martensitic stainless steel laser-deposited coatings

High cooling rates during laser cladding of stainless steels may alter the microstructure and phase constitution of the claddings and consequently change their functional properties. In this research, solidification structures and solid state phase transformation products in single and multi layer AISI 431 martensitic stainless steel coatings deposited by laser cladding at different processing speeds are investigated by optical microscopy, Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), orientation imaging microscopy (OIM), ternary phase diagram, Schaeffler and TTT diagrams. The results of this study show how partitionless solidification and higher solidification rates alter the microstructure and phase constitution of martensitic stainless steel laser deposited coatings. In addition, it is shown that while different cladding speeds have no effect on austenite–martensite orientation relationship in the coatings, increasing the cladding speed has resulted in a reduction of hardness in deposited coatings which is in contrast to the common idea about obtaining higher hardness values at higher cladding speeds.

A systematic review of variables used to assess clinically acceptable alignment of unilateral transtibial amputees in the literature.

Prosthetic alignment is a subjective concept which lacks reliability. The outcome responsiveness to prosthetic alignment quality could help to improve subjective and instrument assisted prosthetic alignment. This study was aimed to review variables used to assess clinically acceptable alignment in the literature. The search was done in some databases including: Google Scholar, PubMed, EBSCO, EMBASE, ISI Web of Knowledge and Scopus. The first selection criterion was based on abstracts and titles to address the research questions of interest. The American Academy of Orthotics and Prosthetics checklists were used for paper risk of bias assessment. A total of 25 studies were included in this study. Twenty-four studies revealed the critics of standing position or walking to locate clinically acceptable alignment, only one study measured outcomes in both situations. A total of 253 adults with transtibial amputations and mean age of 48.71 years participated in included studies. The confidence level of included studies was low to moderate, and before-after trial was the most common study design (n = 19). The joint angle, load line location with respect to joints and center of pressure-related parameters were reported as sensitive outcomes to prosthetic alignment quality in standing posture. The amount of forces at various parts of gait cycle and time of events were sensitive to prosthetic alignment quality during walking. Standing balance and posture and temporal parameters of walking could help to locate clinically acceptable alignment.N/

CD133 (Prominin) Negative Human Neural Stem Cells Are Clonogenic and Tripotent

CD133 (Prominin) is widely used as a marker for the identification and isolation of neural precursor cells from normal brain or tumor tissue. However, the assumption that CD133 is expressed constitutively in neural precursor cells has not been examined

Glass transition with decreasing correlation length during cooling of Fe50Co50 superlattice and strong liquids

The glass transition GT is usually thought of as a structural arrest that occurs during the cooling of a liquid, or sometimes a plastic crystal, trapping a metastable state of the system before it can recrystallize to stabler forms1. This phenomenon occurs in liquids of all classes, most recently in bulk metallic glassformers2. Much theoretical interest has been generated by the dynamical heterogeneity observed in cooling of fragile liquids3, 4, and many have suggested that the slow-down is caused by a related increasing correlation length 5-9. Here we report both kinetics and thermodynamics of arrest in a system that disorders while in its ground state, exhibits a large !Cp on arrest (!Cp = Cp,mobile - Cp,arrested), yet clearly is characterized by a correlation length that is decreasing as GT is approached from above. We show that GT kinetics in our system, the disordering superlattice Fe50Co50, satisfy the kinetic criterion for ideally 'strong' glassformers10, and since !Cp behavior through Tg also correlates10, we propose that very strong liquidsand very fragile liquids exist on opposite flanks of an order-disorder transition - one that is already known for model systems

Aging Skin: Nourishing from Out-In. Lessons from Wound Healing

Skin lesion therapy, peculiarly in the elderly, cannot be isolated from understanding that the skin is an important organ consisting of different tissues. Furthermore, dermis health is fundamental for epidermis integrity, and so adequate nourishment is mandatory in maintaining skin integrity. The dermis nourishes the epidermis, and a healthy epidermis protects the dermis from the environment, so nourishing the dermis through the epidermal barrier is a technical problem yet to be resolved. This is also a consequence of the laws and regulations restricting cosmetics, which cannot have properties that pass the epidermal layer. There is higher investment in cosmetics than in the pharmaceutical industry dealing with skin therapies, because the costs of drug registration are enormous and the field is unprofitable. Still, wound healing may be seen as an opportunity to “feed” the dermis directly. It could also verify whether providing substrates could promote efficient healing and test optimal skin integrity maintenance, if not skin rejuvenation, in an ever aging population

Modeling of miRNA and Drug Action in the EGFR Signaling Pathway

MicroRNAs have gained significant interest due to their widespread occurrence and diverse functions as regulatory molecules, which are essential for cell division, growth, development and apoptosis in eukaryotes. The epidermal growth factor receptor (EGFR) signaling pathway is one of the best investigated cellular signaling pathways regulating important cellular processes and its deregulation is associated with severe diseases, such as cancer. In this study, we introduce a systems biological model of the EGFR signaling pathway integrating validated miRNA-target information according to diverse studies, in order to demonstrate essential roles of miRNA within this pathway. The model consists of 1241 reactions and contains 241 miRNAs. We analyze the impact of 100 specific miRNA inhibitors (anit-miRNAs) on this pathway and propose that the embedded miRNA-network can help to identify new drug targets of the EGFR signaling pathway and thereby support the development of new therapeutic strategies against cancer

Proteomic Analyses Reveal Common Promiscuous Patterns of Cell Surface Proteins on Human Embryonic Stem Cells and Sperms

BACKGROUND: It has long been proposed that early embryos and reproductive organs exhibit similar gene expression profiles. However, whether this similarity is propagated to the protein level remains largely unknown. We have previously characterised the promiscuous expression pattern of cell surface proteins on mouse embryonic stem (mES) cells. As cell surface proteins also play critical functions in human embryonic stem (hES) cells and germ cells, it is important to reveal whether a promiscuous pattern of cell surface proteins also exists for these cells. METHODS AND PRINCIPAL FINDINGS: Surface proteins of hES cells and human mature sperms (hSperms) were purified by biotin labelling and subjected to proteomic analyses. More than 1000 transmembrane or secreted cell surface proteins were identified on the two cell types, respectively. Proteins from both cell types covered a large variety of functional categories including signal transduction, adhesion and transporting. Moreover, both cell types promiscuously expressed a wide variety of tissue specific surface proteins, and some surface proteins were heterogeneously expressed. CONCLUSIONS/SIGNIFICANCE: Our findings indicate that the promiscuous expression of functional and tissue specific cell surface proteins may be a common pattern in embryonic stem cells and germ cells. The conservation of gene expression patterns between early embryonic cells and reproductive cells is propagated to the protein level. These results have deep implications for the cell surface signature characterisation of pluripotent stem cells and germ cells and may lead the way to a new area of study, i.e., the functional significance of promiscuous gene expression in pluripotent and germ cells

Understanding the cancer stem cell

The last 15 years has seen an explosion of interest in the cancer stem cell (CSC). Although it was initially believed that only a rare population of stem cells are able to undergo self-renewing divisions and differentiate to form all populations within a malignancy, a recent work has shown that these cells may not be as rare as thought first, at least in some malignancies. Improved experimental models are beginning to uncover a less rigid structure to CSC biology, in which the concepts of functional plasticity and clonal evolution must be incorporated into the traditional models. Slowly the genetic programmes and biological processes underlying stem cell biology are being elucidated, opening the door to the development of drugs targeting the CSC. The aim of ongoing research to understand CSCs is to develop novel stem cell-directed treatments, which will reduce therapy resistance, relapse and the toxicity associated with current, non-selective agents

Breast cancer stem cells: implications for therapy of breast cancer

The concept of cancer stem cells responsible for tumour origin, maintenance, and resistance to treatment has gained prominence in the field of breast cancer research. The therapeutic targeting of these cells has the potential to eliminate residual disease and may become an important component of a multimodality treatment. Recent improvements in immunotherapy targeting of tumour-associated antigens have advanced the prospect of targeting breast cancer stem cells, an approach that might lead to more meaningful clinical remissions. Here, we review the role of stem cells in the healthy breast, the role of breast cancer stem cells in disease, and the potential to target these cells