Vasorelaxant effects and mechanism of polyphenol compound LM 49 on isolated thoracic aorta of rats / 中国药房

OBJECTIVE To study the vasorelaxant effects and mechanism of polyphenol compound 2，4′，5′-trihydroxy-5，2′- dibromo-diphenyl-methanone（LM49）on isolated aortic rings of rats. METHODS Thoracic aortic vascular rings of rats were collected. Using the diastolic rate as index ， the effects of different concentrations of LM 49 on endothelium-intact and endothelium-denuded aortic rings pre-contracted by norepinephrine （NE，1×10－6 mol/L）or KCl （60 mmol/L）were investigated. After pre-culturing vascular rings by nitric oxide synthase inhibitor L-nitro-arginine methyl ester （L-NAME，0.1 mmol/L） and cyclooxygenase inhibitor indomethacin （1×10－5 mol/L），as well as pre-culturing vascular rings by 4 potassium channel blockers [BaCl 2（0.1 mmol/L），tetraethylammonium（TEA，5 mmol/L），4-aminopyridine（4-AP，0.1 mmol/L）and glibenclamide （1×10－5 mol/L）]，the vasorelaxant effect of different concentrations of LM 49 on the vascular rings were investigated by using the same method. With the percentage of vasoconstriction as the index ，using KCl （60 mmol/L），NE（1×10－6 mol/L），calcium channel blocker verapamil （1×10－6 mol/L）and sarcoplasmic Δ 基金项目 重大新药创制国家科技重大专项 （No.2018ZX097- reticulum Ca 2 +-adenosine triphosphate （ATP） enzyme pump inhibitor thacarotene （TG，1×10－6 mol/L）to induce the release of calcium in vascular rings in the absence of calcium. CaCl was added cumulatively ，and the effect of LM 49 on the cxyw06，vasoconstriction caused by calcium influx induced by CaCl 2 was investigated. RESULTS 3×10－6，5×10－6，1×10－5 mol/L LM49 had a significant relaxation effect on NE and KCl precontracted vascular rings （P＜0.01）； whether the endothelium was removed or not had no significant effect on the vasodilation of LM 49（P＞0.05）. After L-NAME ，indomethacin， TEA and 4-AP was pre-incubated ，different concentrations of LM 49 had no significant effects on aortic rings precontracted by NE （P＞0.05）. Glibenclamide and BaCl 2 could inhibit the vasorelaxant effects of LM 49 on aortic rings precontracted by NE （P＜0.01）. In the absence of calcium ，LM49 could inhibit the contraction caused by calcium influx induced by accumulated CaCl 2 after pre-incubation with KCl ，NE，verapamil and TG （P＜0.01）. CONCLUSIONS LM49 evokes significant relaxation of isolated aortic vascular rings without endothelium dependence ；the mechanism of which is inducing ATP-sensitive potassium channel ， inward rectifier potassium channel open and restraining extracellular Ca 2 + influx via voltage-gated calcium channel ， receptor-operated calcium channel and store-operated calcium channel.

Ultrasonic dynamic focus data reordering design based on FPGA / 中国医疗器械杂志

The existing analog reordering and folding technology has the following problems: it cause the attenuation of the ultrasonic signal, and it is difficult to achieve beam steering in color Doppler ultrasonic diagnostic instrument. This article proposes a design method to achieve digital reordering of dynamic focusing data. The digital reordering is composed of two parts, bit reordering which is implemented with multiplier and byte reordering using switch selection. The results show that it can meet the design requirements using fewer resources.

Simultaneous determination of four flavonoids in Malus prunifolia from Shanxi province by RP-HPLC / 中国中药杂志

<p><b>OBJECTIVE</b>To develop an HPLC method for simultaneous determination of rutin, hyperoside, quercetin and kaempferol in Malus prunifolia from Shanxi province in China.</p><p><b>METHOD</b>The separation was performed on a Hypersil C18 column (4.6 mm x 250 mm, 5 microm), using a gradient elution with methanol-water containing 0.2% phosphoric acid as the mobile phase. The flow rate was 1.0 mL x min(-1), the detection wavelength was 360 nm and the temperature of column was 25 degrees T.</p><p><b>RESULT</b>The linear ranges of rutin, hyperoside, quercetin and kaempferol were 1.87-46.67 mg x L(-1), 6.40-160.0 mg x L(-1), 3.33-83.33 mg x L(-1), 0.80-20.00 mg x L(-1), respectively. The average recoveries (n=6) of the four constituents were 99.2% (RSD 2.9%), 98.2% (RSD 1.9%), 97.4% (RSD 2.3%), 97.2% (RSD 1.3%), respectively.</p><p><b>CONCLUSION</b>The method was simple, accurate and can be used to evaluate medicinal value of Malus prunifolia.</p>