Biomedical subjects
Publications and source records attributed to L S Ma.
We demonstrate optical clockwork without the need for carrier-envelope phase control by use of sum-frequency generation between a continuous-wave optical parametric oscillator at 3.39 microm and a femtosecond mode-locked Ti:sapphire laser with two strong spectral peaks at 834 and 670 nm, a spectral difference matched by the 3.39-microm radiation.
We demonstrate a simple optical clock based on an optical transition of iodine molecules, providing a frequency stability superior to most rf sources. Combined with a femtosecond-laser-based optical comb to provide the phase coherent clock mechanism linking the optical and microwave spectra, we derive an rf clock signal of comparable stability over an extended period. Measurements suggest the stability ( 5x10(-14) at 1 s) of the cw laser locked on the iodine transition is transferred to every comb component throughout the optical octave bandwidth (from 532 to 1064 nm) with a precision of 3.5x10(-15). Characterization of the performance of the optical clock shows (in-)stability below 3x10(-13) at 1 s (currently limited by the microwave sources), and 4.6x10(-13) over one year.
We generated a coherently synthesized optical pulse from two independent mode-locked femtosecond lasers, providing a route to extend the coherent bandwidth available for ultrafast science. The two separate lasers (one centered at 760 nanometers wavelength, the other at 810 nanometers) are tightly synchronized and phase-locked. Coherence between the two lasers is demonstrated via spectral interferometry and second-order field cross-correlation. Measurements reveal a coherently synthesized pulse that has a temporally narrower second-order autocorrelation width and that exhibits a larger amplitude than the individual laser outputs. This work represents a new and flexible approach to the synthesis of coherent light.
OBJECTIVE: To establish quality standards for safe and correct use of Rabdosia lophanthoides. METHOD: Field investigation and pharmacognostic study. RESULT: R. lophanthoides was confirmed as a derivative of R. lophanthoides. CONCLUSION: A convenient and effective method for identifying the herb has been established.
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The curative effects of combined traditional Chinese and Western medicine in 508 patients of intractable peptic ulcer with gastroscopy confirmation were evaluated. The patients were divided into Chuanjia Weidan group (Group I, 260 patients) and cimetidine group (Group II, 248 patients). Debridement, injection and drug covering of ulcer surfaces were followed by oral Chinese medicine Chuanjia Weidan (50 g daily) or cimetidine (800 mg every night) for 4 weeks. In group I, 95.6% of patients with gastric ulcer were cured, while in group II, 87.2% with the same disease were cured. For the patients with duodenal ulcer in group I and group II, 88.2% and 85.2% were cured respectively (P > 0.05). 70% of the main symptoms were remitted in the first and 97% in the second week in group I, whereas in group II, the remission occurred in 33% and 64.5% respectively (P < 0.05). The clearance rate of Helicobacter pylori for gastric ulcer and duodenal ulcer in group I was 71.2% and 78.3% respectively, but 5.3% and 7.2% in group II (P < 0.01). Eighteen months after the treatment, 13% of the patients with gastric ulcer and 14.2% with duodenal ulcer in group I relapsed, while that of group II was 63% and 71.3% respectively (P < 0.01). The authors concluded that debridement, injection and drug covering of ulcer surface under the endoscopy associated with oral administration of Chinese medicine Chuanjia Weidan is efficacious in treating intractable peptic ulcer.
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