RESUMEN
We demonstrate a high-power, high-energy chirped-pulse amplification (CPA) system based on three Yb:YAG amplifiers and a chirped-volume Bragg grating (CVBG). With an all-fiber laser as the seed light, a Yb:YAG rod amplifier and two Yb:YAG single-crystal fiber (SCF) amplifiers as the amplification stages, a laser power of 96 W at 200 kHz repetition rate corresponding to a pulse energy of 0.48 mJ has been generated. The stability of different output power has been measured and compared. To the best of our knowledge, this is the first report on a stable 100 W-level laser with sub-mJ pulse energy based on SCF. The beam quality M2 of different output lasers has also been measured, which is below 1.55 when the output power is 92 W. The amplified laser is seeded into the CVBG to be compressed, and a compression efficiency of 0.724 has been obtained with an output power of 67.8 W and pulse duration of 2.5 ps. The ultrafast CPA system delivering high pulse energy (sub-mJ) with hundreds of kHz repetition rate is expected to be used as the driving source of high-flux high-harmonic generation after further compression.
RESUMEN
This study was performed to investigate the possible involvement of polyamines in the development of cervical cancer. The objective of the present study was therefore to find the specific polyamine indicators, which could be used as useful markers for the early determination of cervical cancer. A simple method for the simultaneous determination of plasma concentrations of five polyamines in normal and U14 model mice was developed by using HPLC-MS. The samples were derivatized by benzoyl chloride. The derived polyamines were separated on a C18 column by a gradient elution with methanol-water, and then detected with HPLC-MS. The results showed that all polyamine levels in the U14 model mice were higher than those in normal ones. The cadaverine, putrescine and 1, 3-diaminopropane levels were significantly higher in U14 model mice plasma than those in normal mice plasma, especially the putrescine and 1, 3-diaminopropane (P<0.01). The cadaverine, putrescine and 1, 3-diaminopropane levels were significantly higher in U14 mice model urine than those in normal mice urine, especially the cadaverine and 1, 3-diaminopropane (P<0.01). Putrescine, cadaverine and 1, 3-diaminopropane might be the indicators of the cervical cancer.
RESUMEN
Four alkaloids, strychnine, soladulcidine, solamargine and (3-O-beta-D-glucopyranosyl-(1 --> 2)beta-D-glucopyranosyl-(1 --> 4)-beta-D-galactopyranoside-(25xi)-solanidan-3beta,23beta-diol)(abbreviation, glycoalkaloid A) were isolated from Solanum lyratum Thunb. The structures were elucidated by NMR and measuring physicochemical properties. Then a novel and rapid method using an ultra-performance liquid chromatography coupled with mass spectrometry was developed and validated for the simultaneous determination of these compounds. An acquit UPLC BEH C18 column (2.1 mm x 50 mm, 1.7 microm) was used. Acetonitrile and 0.1% formic acid were adopted as mobile phase. Detection was performed on a Waters Micromass Quattro Premier tandem quadrupole mass spectrometer in the positive ion mode using an electrospray source. The multiple reaction monitoring (MRM) mode was used to detect the target compounds. The established method showed a good linearity (R2 > 0.999 0) over the investigated concentration ranges, good inter-day and intra-day precisions (less than 2%) and good recoveries (from 99.8% to 100.1%) for all four target compounds. Compared to previous methods employing conventional high performance liquid chromatography (HPLC) separation, the ultra-high-pressure liquid chromatography-tandem mass spectrometry achieved preferable chromatographic parameters and significantly increased sample throughput.