Early Cell Response to Mechanical Stimuli during TBI

Traumatic brain injury (TBI) refers to brain damage resulting from external mechanical forces such as a blast or crash. The tissue and cell deformations caused by shear forces are the most common pathological features in TBI and lead to long-term symptoms. Our current understanding of TBI derives mainly from in vivo studies of poststimulus pathology and the effects on brain function. Little is known about the early responses of brain cells during mechanical stimuli. In this chapter, we evaluate the early cell response to the rapid shear forces in vitro. We introduce advanced technologies capable of generating fast shear stimuli mimicking forces occurring in TBI and reporting internal forces in specific proteins at the time of injury. We define the threshold shear forces for calcium influx using an astrocyte model. We describe the spatiotemporal distribution of cytoskeletal forces and correlate them with variations in cell membrane tension. This chapter makes a strong argument that cells’ response to external forces is nonlinear. The heterogeneous distribution of cytoskeletal tension and the gradient of protein forces play a key role in the cells’ response to mechanical stimuli

Ballistic magnetoresistance in nickel single-atom conductors

Large ballistic magnetoresistance (BMR) has been measured in Ni single-atom conductors electrodeposited between microfabricated thin films. These measurements irrefutably eliminate any magnetostriction related artifacts in the BMR effect.Comment: 12 pages, 3 Figure

An Overview of Recent Strategies in Pathogen Sensing

Pathogenic bacteria are one of the major concerns in food industries and water treatment facilities because of their rapid growth and deleterious effects on human health. The development of fast and accurate detection and identification systems for bacterial strains has long been an important issue to researchers. Although confirmative for the identification of bacteria, conventional methods require time-consuming process involving either the test of characteristic metabolites or cellular reproductive cycles. In this paper, we review recent sensing strategies based on micro- and nano-fabrication technology. These technologies allow for a great improvement of detection limit, therefore, reduce the time required for sample preparation. The paper will be focused on newly developed nano- and micro-scaled biosensors, novel sensing modalities utilizing microfluidic lab-on-a-chip, and array technology for the detection of pathogenic bacteria

Parent-of-origin-specific allelic associations among 106 genomic loci for age at menarche.

Age at menarche is a marker of timing of puberty in females. It varies widely between individuals, is a heritable trait and is associated with risks for obesity, type 2 diabetes, cardiovascular disease, breast cancer and all-cause mortality. Studies of rare human disorders of puberty and animal models point to a complex hypothalamic-pituitary-hormonal regulation, but the mechanisms that determine pubertal timing and underlie its links to disease risk remain unclear. Here, using genome-wide and custom-genotyping arrays in up to 182,416 women of European descent from 57 studies, we found robust evidence (P < 5 × 10(-8)) for 123 signals at 106 genomic loci associated with age at menarche. Many loci were associated with other pubertal traits in both sexes, and there was substantial overlap with genes implicated in body mass index and various diseases, including rare disorders of puberty. Menarche signals were enriched in imprinted regions, with three loci (DLK1-WDR25, MKRN3-MAGEL2 and KCNK9) demonstrating parent-of-origin-specific associations concordant with known parental expression patterns. Pathway analyses implicated nuclear hormone receptors, particularly retinoic acid and γ-aminobutyric acid-B2 receptor signalling, among novel mechanisms that regulate pubertal timing in humans. Our findings suggest a genetic architecture involving at least hundreds of common variants in the coordinated timing of the pubertal transition