Molecular spectroscopy of living systems

Molecular spectroscopy has been a powerful tool in the study of molecules in gas phase, condensed phase, and at interfaces. The transition from in vitro spectroscopy to spectroscopic imaging of living systems is opening new opportunities to reveal cellular machinery and to enable molecule-based diagnosis (Science 2015, 350: 1054). Such a transition involves more than a simple combination of spectrometry and microscopy. In this presentation, I will discuss the most recent efforts that have pushed the physical limits of spectroscopic imaging in terms of spectral acquisition speed, detection sensitivity, spatial resolution and imaging depth. I will further highlight significant applications in functional analysis of single cells and in label-free detection of diseases

The Effect of Geometric Configurations on the Elastic Behavior of an Edge-Cracked Bonded Strip

Interface cracks often initiate around the bonding free-edge corner due to the high-stress concentration. In this research, the elastic behavior of an edge-cracked dissimilar bonded strip subjected to remote tensile load is investigated using the proportional crack tip opening displacement method based on FE analysis for arbitrary material combinations. The stress intensity factor, energy release rate, and mode mixity are computed and compared systematically with varying geometrical configurations and material combinations. Then, the combined effects of the relative height of the bonded component and material combination are discussed for the typical engineering materials

Nanomedicine for treating spinal cord injury

Spinal cord injury results in significant mortality and morbidity, lifestyle changes, and difficult rehabilitation. Treatment of spinal cord injury is challenging because the spinal cord is both complex to treat acutely and difficult to regenerate. Nanomaterials can be used to provide effective treatments; their unique properties can facilitate drug delivery to the injury site, enact as neuroprotective agents, or provide platforms to stimulate regrowth of damaged tissues. We review recent uses of nanomaterials including nanowires, micelles, nanoparticles, liposomes, and carbon-based nanomaterials for neuroprotection in the acute phase. We also review the design and neural regenerative application of electrospun scaffolds, conduits, and self-assembling peptide scaffolds

Stress intensity factor solutions for several crack problems using the proportional crack opening displacements

A general finite element procedure based on the proportional crack opening displacements for obtaining the stress intensity factors is presented. The procedure is applied to the nonsingular 3-node linear, 4-node linear, 8-node parabolic, 8-node axisymmetric elements and 8-node hexahedral solid elements for a test. It is found that the current method exhibits good element type adaptability and significantly less mesh dependency, and accurate results can be obtained effectively using rather coarse meshes. The accuracy of the current procedure is evaluated by applying it to two-dimensional interface cracks, three-dimensional penny-shaped cracks as well as circumferential surface cracks. Comparison with the published data from the literature shows that the current procedure gives accurate stress intensity factors. Furthermore, the current method is fairly efficient and less computational resource consuming and can be used as an effective tool in the reliability analysis of the bonded multi-layers