Ultrasensitive Acetylcholinesterase detection based on a surface-enhanced Raman scattering lever strategy for identifying nerve fibers.

Accurate discriminating nerve fibers is a prerequisite for right suturing nerves in nerve transfer operation. Various methods have been developed for identification of motor and sensory fibers, but no simple method meets the requirements in clinic. In this study, a surface-enhanced Raman scattering (SERS) lever strategy is designed and developed to detect Acetylcholinesterase (AchE) ultrasensitively, in which using produced thiocholine with weak intrinsic Raman activity (four ounces) to adjust absorbance of Rhodamine B with strong intrinsic Raman activity (thousand catties) on SERS-active substrates is to increase the sensitivity. Employing a miniaturized SERS substrate, SERS-active microneedles, is to decrease the volume of enzymolysis systems. Adopting an internal reference is to increase the repeatability of collected signal. The ultrasensitive AchE detection method discriminate samples with four times of difference in enzyme activity between 1-1 × 10-4 U/mL in about 10 min of enzymolysis time. AchE amounts in 2-mm-long segments of ventral and dorsal roots were about 0.00025-0.001 U and 0.01-0.02 U, respectively. The developed method would be a reliable method met the requirements of identifying motor and sensory fibers in clinic.

[The research progress on microelectrode array (MEA) of retinal prosthesis].

This review paper presents the current research progress, challenges and future development on microelectrode array of retinal prosthesis, including epi-retinal and sub-retinal implants.

[The research on multi-layer flexible microelectrode arrays of epiretinal prosthesis].

This paper proposed a new design on multi-layer flexible microelectrode arrays (MEA) of epiretinal prosthesis, as well as a set of automatic testing system to evaluate and analyze the MEA. Experiment results showed that the MEA was satisfying on both flexibility and impedance and the multi-layer design didn't introduce significant differences.

[Simultaneous determination of 5 active components in Fructus Cnidii by HPLC].

OBJECTIVE: To develop an RP-HPLC method for simultaneous determination of 5 constituents in Fructus Cnidii. METHOD: Analysis was performed on an Alltech C18 (4.6 mm x 250 mm, 5 microm) column. The mobile phases were acetonitrile water and acetic acid with gradient elution. The flow rate was 1 mL x min(-1). The monitoring wavelength was 325 nm and 245 nm. The column temperature was 40 degrees C. RESULT: The linear response ranges were 1-20 microg x mL(-1) (r = 0.999 9) for xanthotoxin, 1-20 microg x mL(-1) (r = 0.999 9) for isopimpinellin, 11-20 microg x mL(-1) (r = 0.999 8) for bergapten, 100-1 200 microg x mL(-1) (r = 0.999 7) for imperatorin, 100-2 000 microg x mL(-1) (r = 0.999 9) for osthole. The average recoveries were all above 95%. CONCLUSION: The method is simple, sensitive and accurate with good reproducibility.