传统的正交频分复用(Orthogonal frequency division multiplexing,OFDM)信号压缩算法由于低的压缩比和低的信号量化误差比(Signal to quantization-error ratio,SQR)造成较高的误码率,无法满足OFDM系统的需求。为了实现高的压缩比和低...传统的正交频分复用(Orthogonal frequency division multiplexing,OFDM)信号压缩算法由于低的压缩比和低的信号量化误差比(Signal to quantization-error ratio,SQR)造成较高的误码率,无法满足OFDM系统的需求。为了实现高的压缩比和低的误码率,提出了一种联合削峰尾插(Clipping with tail plug,CTP)技术、几何级数压扩(Geometric series companding,GSC)技术及部分采样点校正(Partial sample calibration,PSC)技术的准无损压缩算法。计算机仿真结果表明,对于4096-正交幅度调制(Quadrature amplitude modulation,QAM)的OFDM信号,压缩比最高可达1.86∶1,误码率低于10-7,量化误差对应的平均SQR高达70dB,因而能够很好地满足光纤到分配点+千兆数字用户线路(Fiber to the distribution point+GCga digital subscriber line,FTTdp+GDSL)系统的需求。展开更多
目的:介绍一种简易、多用途的小鼠固定装置的制作和使用方法。方法:选用废弃的50 m L离心管,按设计方案进行切割、组装制成简易小鼠固定装置。选取60只小鼠,随机分为2组,对照组采用传统固定方法,研究组则采用本装置固定,先后对小鼠进行...目的:介绍一种简易、多用途的小鼠固定装置的制作和使用方法。方法:选用废弃的50 m L离心管,按设计方案进行切割、组装制成简易小鼠固定装置。选取60只小鼠,随机分为2组,对照组采用传统固定方法,研究组则采用本装置固定,先后对小鼠进行尾静脉注射、断尾采血、膝关节腔内注射,观察比较两组操作时间和成功率等指标。结果:单个50 mL离心管仅重约12 g,制作时间约15 min。对照组和研究组小鼠尾静脉注射时间分别是(32.10±1.97)s和(30.27±2.20)s,成功率均为100%,断尾采血时间分别是(30.10±1.73)s和(28.67±1.55)s,成功率也均为100%,两组在操作时间上差异均具有统计学意义(P<0.01),而在成功率方面均无统计学差异(P>0.05)。两组膝关节腔内注射时间分别是(40.77±2.73)s和(38.73±2.16)s,成功率分别为83.33%和95.00%,两组在操作时间及成功率方面差异均具有统计学意义(P<0.05)。结论:该小鼠固定装置具有材料易得、制作简单、携带方便、用途多样等优点,为实验小鼠的固定提供了一种新的安全、实用的方法。展开更多
Objective:To evaluate the analgesic activity of the ethyl acetate,methanol and aqueous extracts of Plewotus eous(P.eous) mushroom.Methods:The dried fruiting bodies were extracted with ethyl acetate,methanol and water....Objective:To evaluate the analgesic activity of the ethyl acetate,methanol and aqueous extracts of Plewotus eous(P.eous) mushroom.Methods:The dried fruiting bodies were extracted with ethyl acetate,methanol and water.The analgesic effect of extracts of P.eous were investigated at doses 250 500 and 1 000 mg/kg body weight,using acetic-acid induced writhing,hot-plate,tail immersion and tail-clip tests.Results:P.eous extracts produced significant reduction in number of writhes induced by intraperitoneal injection of acetic-acid(P【0.05).Moreover,in hot-plate and tail immersion test,all the three extracts significantly raised the pain threshold at different time of observation(0-60 min) in comparison with control(P【0.05).In tail-clip test the extracts also caused a significant inhibition of pain at both the doses used(P【0.05).Conclusions:The results of present study suggest that extracts of P.eous possess potent analgesic property and could serve as a base for future drugs.展开更多
Objective:To evaluate the anti-inflammatory and analgesic activities of the ethanol and aqueous extracts of prop roots of Pandanus fascicularis(P.fascicularis) Lam(pandanaceae).And provide experimental evidence for it...Objective:To evaluate the anti-inflammatory and analgesic activities of the ethanol and aqueous extracts of prop roots of Pandanus fascicularis(P.fascicularis) Lam(pandanaceae).And provide experimental evidence for its traditional use such as rheumatoid arthritis and spasmodic. Methods:The anti-inflammatory activity was observed by carrageenan-induced edema of the hind paw of rats.Analgesic activities of prop roots of P.fascicularis were determined using acetic acid induced writhing model and tail clip method in mice and rat,respectively.The ethanol fraction was then subjected to chromatographic analysis and a compound has been isolated and characterized by IR,~1H-NMR and mass spectroscopy.Results:Edema suppressant effect of ethanol extract was found to be 37.03%inhibition whereas aqueous extract was found to be 63.22%inhibition after 3 h which was nearly equivalent to that of 10 mg/kg of indomethacin (67.81%).Percentage inhibition of writhing compared to control were 63.15%,54.38%,14.90%for aspirin,aqueous extract and ethanolic extract,respectively.Both ethanol and aqueous extracts show significant activity against appropriate controls after 60 min of treatment on tail clip method. The structure of the isolated compound is may be characterized as Hepta deca-5-ene-l-ol by analysis it’s IR,H-NMR and mass spectroscopy data.Conclusions:The extracts of prop roots of P.fascicularis produce significant analgesic and anti-inflammatory activities,supporting the traditional application of this herb in treating various diseases associated with inflammation and pain.展开更多
Objective:To evaluate the ann-nociceptive activity of Tecomaria capensls(T.capensis) leaves extract(TCLE) using different models in rats by acetic acid induced writhing test,(b) tail-flick test(c) tail-clip test.Metho...Objective:To evaluate the ann-nociceptive activity of Tecomaria capensls(T.capensis) leaves extract(TCLE) using different models in rats by acetic acid induced writhing test,(b) tail-flick test(c) tail-clip test.Methods:TCLE(100,300,1000 and 2000 mg/kg body wt.) was given to rats orally to observe acute toxicity for 14 d.Then test drug TCLE were given at dose of 100,200 and 500 mg/kg p.o.and standard drug aspirin were given at a dose of 100 mg/kg p.o.Results:No mortality was reported even after 14 d.This indicates that the methanol extract is safe up to a single dose of 2 000 mg/kg body weight TCLE(100,200 and 500 mg/kg p.o.) significandy inhibited abdominal constrictions(writhing) induced by acetic acid and increased the latency period in the tail flick and tail clip test.TCLE at the dose of 500 mg/kg showed significant anti-nociceptive activity compared to standard aspirin.Discussions:The results of this study show that methanol extract of T.capensis possesses anti-nociceptive activity which may be mediated by the central and peripheral mechanisms.展开更多
文摘传统的正交频分复用(Orthogonal frequency division multiplexing,OFDM)信号压缩算法由于低的压缩比和低的信号量化误差比(Signal to quantization-error ratio,SQR)造成较高的误码率,无法满足OFDM系统的需求。为了实现高的压缩比和低的误码率,提出了一种联合削峰尾插(Clipping with tail plug,CTP)技术、几何级数压扩(Geometric series companding,GSC)技术及部分采样点校正(Partial sample calibration,PSC)技术的准无损压缩算法。计算机仿真结果表明,对于4096-正交幅度调制(Quadrature amplitude modulation,QAM)的OFDM信号,压缩比最高可达1.86∶1,误码率低于10-7,量化误差对应的平均SQR高达70dB,因而能够很好地满足光纤到分配点+千兆数字用户线路(Fiber to the distribution point+GCga digital subscriber line,FTTdp+GDSL)系统的需求。
文摘Objective:To evaluate the analgesic activity of the ethyl acetate,methanol and aqueous extracts of Plewotus eous(P.eous) mushroom.Methods:The dried fruiting bodies were extracted with ethyl acetate,methanol and water.The analgesic effect of extracts of P.eous were investigated at doses 250 500 and 1 000 mg/kg body weight,using acetic-acid induced writhing,hot-plate,tail immersion and tail-clip tests.Results:P.eous extracts produced significant reduction in number of writhes induced by intraperitoneal injection of acetic-acid(P【0.05).Moreover,in hot-plate and tail immersion test,all the three extracts significantly raised the pain threshold at different time of observation(0-60 min) in comparison with control(P【0.05).In tail-clip test the extracts also caused a significant inhibition of pain at both the doses used(P【0.05).Conclusions:The results of present study suggest that extracts of P.eous possess potent analgesic property and could serve as a base for future drugs.
文摘Objective:To evaluate the anti-inflammatory and analgesic activities of the ethanol and aqueous extracts of prop roots of Pandanus fascicularis(P.fascicularis) Lam(pandanaceae).And provide experimental evidence for its traditional use such as rheumatoid arthritis and spasmodic. Methods:The anti-inflammatory activity was observed by carrageenan-induced edema of the hind paw of rats.Analgesic activities of prop roots of P.fascicularis were determined using acetic acid induced writhing model and tail clip method in mice and rat,respectively.The ethanol fraction was then subjected to chromatographic analysis and a compound has been isolated and characterized by IR,~1H-NMR and mass spectroscopy.Results:Edema suppressant effect of ethanol extract was found to be 37.03%inhibition whereas aqueous extract was found to be 63.22%inhibition after 3 h which was nearly equivalent to that of 10 mg/kg of indomethacin (67.81%).Percentage inhibition of writhing compared to control were 63.15%,54.38%,14.90%for aspirin,aqueous extract and ethanolic extract,respectively.Both ethanol and aqueous extracts show significant activity against appropriate controls after 60 min of treatment on tail clip method. The structure of the isolated compound is may be characterized as Hepta deca-5-ene-l-ol by analysis it’s IR,H-NMR and mass spectroscopy data.Conclusions:The extracts of prop roots of P.fascicularis produce significant analgesic and anti-inflammatory activities,supporting the traditional application of this herb in treating various diseases associated with inflammation and pain.
基金supported by the management and faculty of Jaipur National University,Jaipur,Rajasthan,India
文摘Objective:To evaluate the ann-nociceptive activity of Tecomaria capensls(T.capensis) leaves extract(TCLE) using different models in rats by acetic acid induced writhing test,(b) tail-flick test(c) tail-clip test.Methods:TCLE(100,300,1000 and 2000 mg/kg body wt.) was given to rats orally to observe acute toxicity for 14 d.Then test drug TCLE were given at dose of 100,200 and 500 mg/kg p.o.and standard drug aspirin were given at a dose of 100 mg/kg p.o.Results:No mortality was reported even after 14 d.This indicates that the methanol extract is safe up to a single dose of 2 000 mg/kg body weight TCLE(100,200 and 500 mg/kg p.o.) significandy inhibited abdominal constrictions(writhing) induced by acetic acid and increased the latency period in the tail flick and tail clip test.TCLE at the dose of 500 mg/kg showed significant anti-nociceptive activity compared to standard aspirin.Discussions:The results of this study show that methanol extract of T.capensis possesses anti-nociceptive activity which may be mediated by the central and peripheral mechanisms.