A Direct Electrochemical Detection Method of Melanoma Based on Melanoma Biomarker

A new method of detecting and diagnosing melanoma based on melanoma biomarker was developed and its feasibility demonstrated. The method is based on an electrochemical biosensor platform comprised of a special biochip and device, performing a multi‐channel amperometric detection of the enzymatic activity of tyrosinase, an enzyme biomarker of melanoma. The newly developed biosensor platform is able to electrochemically detect tyrosinase activity in fresh biopsy samples. This bioelectrochemical detection method is rapid, yielding results within minutes from biopsy removal. Using “as is” biopsy samples, without pretreatment, simplifies the process, saves time and reduces cost and labor dramatically. Using modern portable microelectronics provides an accurate biomarker expression measurement at the “point of care” increasing the accessibility of new bio‐chip technologies to the public.     

Optical second-harmonic generation in atomic thallium vapor

We observe coherent optical second-harmonic generation in atomic thallium vapor when the fundamental is tuned to half the resonance frequency of the following transitions: $\text{6}{}^2\text{P}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{? 7}{}^2\text{P}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$ and $\text{6}{}^2\text{P}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{? 8}{}^2\text{P}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$ in the presence of a static magnetic field; and $\text{6}{}^2\text{P}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{? 7}{}^2\text{P}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{, 6}{}^2\text{P}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{? 8}{}^2\text{P}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$in the absence of any external field.     

Resonance fluorescence during phase-controlled transient excitation

The response of a two-level atom to a resonant driving field can be dramatically altered by a sudden shift in the driving field's phase. We discuss the implications of this fact with respect to the atom's transient fluorescence spectrum and relaxation properties.     

Stimulated photon echo study of Na(32S12)-CO velocity-changing collisions

Using the recently developed single-state stimulated photon echo technique, we have studied the velocity changes experienced by ground-state Na atoms in collisions with carbon monoxide molecules. We find that the ground-state Na atoms have a total cross section of ≈420 Ų for velocity-changing collisions with CO, and that they experience an average velocity change of ≈600 cm/s. A scattering kernel of exponential form is shown to be consistent with our results. We discuss the essential features of the estimated photon echo technique.