There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Optical detection and spectroscopy of single molecules and single nanoparticles have been achieved at room temperature with the use of surface-enhanced Raman scattering. Individual silver colloidal nanoparticles were screened from a large heterogeneous population for special size-dependent properties and were then used to amplify the spectroscopic signatures of adsorbed molecules. For single rhodamine 6G molecules adsorbed on the selected nanoparticles, the intrinsic Raman enhancement factors were on the order of 10 14 to 10 15 , much larger than the ensemble-averaged values derived from conventional measurements. This enormous enhancement leads to vibrational Raman signals that are more intense and more stable than single-molecule fluorescence.

http://science.sciencemag.org/content/sci/275/5303/1102.full.pdf

Probing Single Molecules and Single Nanoparticles by Surface-Enhanced Raman Scattering

https://cyberleninka.org/article/n/148766.pdf

Cytochrome P450 enzymes in drug metabolism: Regulation of gene expression, enzyme activities, and impact of genetic variation

This paper presents an in-depth study of Surface Enhanced Raman Scattering (SERS) enhancement factors (EFs) and cross-sections, including several issues often overlooked. In particular, various possible rigorous definitions of the SERS EFs are introduced and discussed in the context of SERS applications, such as analytical chemistry and single molecule SERS. These definitions highlight the importance of a careful characterization of the non-SERS cross-sections of the probes under consideration. This aspect is illustrated by experimental results for the non-SERS cross-sections of representative SERS probes along with average SERS EFs for the same probes. In addition, the accurate experimental determination of single molecule enhancement factors is tackled with two recently developed techniques, namely:  bi-analyte SERS (BiASERS) and temperature-dependent SERS vibrational pumping. We demonstrate that SERS EFs as low as 107, as opposed to the figure of 1014 often claimed in the literature, are sufficient for...

Surface Enhanced Raman Scattering Enhancement Factors: A Comprehensive Study

Resultats d'etudes par diffusion Raman augmentee en surface et par des mesures fluorescentes. Mise en evidence de l'existence de 2 types de sites d'adsorption

Surface-enhanced resonance Raman spectroscopy of Rhodamine 6G adsorbed on colloidal silver

Protein and heme structural changes of ferric and ferrous cytochrome c (Cyt-c) that are induced by electrostatic binding (e.g., liposomes, electrodes), by hydrophobic interactions (e.g., monomeric sodium dodecyl sulfate), by guanidium hydrochloride (GuHCl), and at low pH and high temperature were studied by UV−vis absorption, circular dichroism (CD), electron paramagnetic resonance (EPR), and (surface-enhanced) resonance Raman [(SE)RR] spectroscopy. In a global spectral analysis, all species that differ with respect to the heme structure were identified and characterized in terms of the spin and ligation state of the heme as well as of protein secondary and tertiary structure changes. The results indicate that the upper part of the heme pocket including the Met-80 ligand is the most labile protein region such that this ligand is dissociated from the heme iron in all nonnative Cyt-c states. Among these states, there are two six-coordinated low-spin (LS) configurations with H2O or His-33 serving as the sixt...

Spectroscopic Characterization of Nonnative Conformational States of Cytochrome c

The heme protein cytochrome c acts as an electron carrier at the mitochondrial-membrane interface and thus exerts its function under the influence of strong electric fields. To assess possible consequences of electric fields on the redox processes of cytochrome c, the protein can be immobilized to self-assembled monolayers on electrodes and studied by surface-enhanced resonance Raman spectroscopy. Such model systems may mimic some essential features of biological interfaces including local electric field strengths. It is shown that physiologically relevant electric field strengths can effectively modulate the electron-transfer dynamics and induce conformational transitions.

Electron-transfer processes of cytochrome C at interfaces. New insights by surface-enhanced resonance Raman spectroscopy.

Role of water in bacteriorhodopsin's chromophore: resonance Raman study

Mutational Analysis of Deinococcus radiodurans Bacteriophytochrome Reveals Key Amino Acids Necessary for the Photochromicity and Proton Exchange Cycle of Phytochromes

Peter Hildebrandt

Papers

Surface-enhanced resonance Raman spectroscopy of Rhodamine 6G adsorbed on colloidal silver

Spectroscopic Characterization of Nonnative Conformational States of Cytochrome c

Electron-transfer processes of cytochrome C at interfaces. New insights by surface-enhanced resonance Raman spectroscopy.

Role of water in bacteriorhodopsin's chromophore: resonance Raman study

Mutational Analysis of Deinococcus radiodurans Bacteriophytochrome Reveals Key Amino Acids Necessary for the Photochromicity and Proton Exchange Cycle of Phytochromes