the tip across the material. The final method of imaging with the AFM is non-contact mode. This method is performed by oscillating the cantilever above its resonate frequency so that is is vibrating with an amplitude of 1-10nm. When placed near the surface of an object, the attractive van der Waals forces affect the probe's oscillations. This data is extrapolated and the location of the object is determined. The information is then fed back into the AFM so that the probe can be adjusted to maintain
demonstrates a facile, one−pot preparation of casein hydrolytic peptides (CHPs)–conjugated crystalline AuNPs having average core size about 20 ±10 nm and morphology found to be hexagonal shaped. The CHPs are competent to form the monolayer on the AuNPs surface resulting electrostatic interparticles interaction, and plays an important role in stability for long periods of time (12 months). The X−ray photoelectron (XPS) spectrum, showed a strong peak for the pure ‘Au’ phase. The FTIR spectrum indicated that
Surface plasmon resonance sensor is a promising optical sensor. In 1902, Wood discovered that there are loss of small area in the spectrum after the light beam passed through a grating[4]. This discovery has been intensified by many researchers. Until 1971, Kretschmann used a prism as a substrate and covered its bottom with thick metal film to achieve SPR detection [5]. Thereafter, SPR technology achieved great development. According to Liu and his colleagues in 2013, this prism based SPR sensor
temperature calculation. Combining with SERS sensor, the weak Raman scattering could be dramatically enhanced, which is usually called Surface-enhance Raman spectroscopy (SERS). It will provide a powerful technique to observe very subtle bond variation information in ultra-thin film samples and interphases. This study attempts to understand the in-situ kinetic surface nano-structure, reaction and interfacial analysis by using Raman spectroscopy. The main techniques are SERS with several types of SERS
pre-initiation complex in transcription, different methods such as co-immunoprecipitation (co-IP), glutathione-S-transferase (GST) pull down assays, yeast-two-hybrid (Y2H) assays, isothermal titration calorimetry (ITC), surface plasmon resonance (SPR), nuclear magnetic resonance (NMR) spectroscopy and etc. can be use to validate PPIs. Yet, doing one experiment using one method is not enough to validate the PPI between two or more proteins. Factors such as overexpression of proteins and manipulation
Abstract Every 67 seconds someone in the United States develops Alzheimer's disease (AD). AD is a neurodegenerative condition characterized by cognitive decline accompanied by memory loss. It is the only top ten cause of death in the United States which cannot be prevented, cured, or slowed. One of the proposed causes of AD is the formation of structures containing amyloid fibrils. Amyloid fibrils are insoluble fibrous protein aggregates sharing specific structural traits. Aside from AD, amyloid
(Eugene P. Pendergrass New Horizons Lecture, Radiological Society of North America meeting, 2007)1. Molecular imaging aims at developing imaging instruments, imaging probes, assays, and quantification methods. Imaging can be done using magnetic resonance imaging (MRI), X-ray computed tomography (CT), positron emission tomography (PET), single photon emission computed tomography (SPECT), and optical (bioluminescence and fluorescence imaging)etc. The process of imaging can be elucidated as below:
Nasopharyngeal carcinoma is one of the head and neck cancer and it’s incidence is less than 1 per 100000 population (about 2-3%). Surgery, chemotherapy and radiotherapy are common treatment modalities for nasopharynx cancer. Nasopharynx is surrounded by critical organs such as brain stem, spinal cord, temporal lobes, eyes, middle and inner ears and parotid glands; so it is impossible to deliver high doses to the tumor. Therefore, nasopharyngeal carcinoma presented a challenge to radiotherapy and
Nanoparticles Nanoparticles are defined as the microscopic particles with at least one dimension less than 100 nm. Nanoparticles are of immense scientific interest because of their vast potential applications in biomedicines, computer, electronics, and defense industries. Nanoparticles are of great scientific and technological interests because they can effectively act as bridge between the bulk form and atomic or molecular structures of the materials. Bulk materials possess constant physical and
UV-Vis spectroscopy The reduction of silver ions was observed using spectroscopic analysis by measuring the spectral wave length change and observed a peak at 430nm. The spectrum produced due to the bioreduction of silver ions and its Surface Plasmon Resonance (SPR) at room temperature was observed using Thermo UV10 Spectrophotometer at a band width of 1nm. FTIR Spectroscopy Silver nanoparticles synthesized solution was centrifuged at 15000 rpm for fifteen minutes to obtain the SNP pellets and
2.1 NANOTECHNOLOGY: Many main technological innovations in the 21st century is expected to be based on nanotechnology (Mukunthan et al., 2011). It is a rapidly growing multidisciplinary field which includes many branches of science like physics, chemical engineering, super molecular chemistry, mechanical engineering, material sciences, biotechnology and medicine (Dondaa et al., 2013). Bio nanotechnology integrates biotechnology and nanotechnology for developing biosynthetic and environmental-friendly
2.5.1 Raman Spectroscopy Inelastic scattering of light by elementary excitations such as phonons and plasmon in the material is termed as Raman scattering. When a beam of light (UV-Visible and IR region) of frequencyI is incident on a solid, most of the light gets scattered elastically, i.e., without change in energy. A small fraction of light is scattered inelastically with frequencies I ± m, where m are the characteristic vibrational frequencies of the e- cloud in the molecule/solid. Figure