Earplugs have effects on preventing noise. Many earplugs developed, when being used, may hinder speech communication because of their lack in frequency selectivity of attenuation.A new type earplug called a high-low frequency(HLF)earplug has been desingned. There is a Zigzag channel in the earplug, which lets speaking tones pass and absorbes high frequency noise. So it doesn't influence communication. And it could attenuate noise if channel be closed as well in an environemt with low frequency.According to Iso4869-1981 standard. HLF earplug's average attenuation is 29.1 dB. When the channel is opened its attenuation will be below 10 dB at low frequency; about 30 dB at high frequen-cy.

This paper reports the method for evaluating the speech intelligibility . of ear protectors.Twenty subjects wearing 3 types of ear plugs ("MT-86", "65", "85-Ⅱ" ear plugs) were presented with stable 50-Chinese-word signals. The results show that the intelligibility was higher with "MT-86" than with "65" and "85-Ⅱ ", and this method was a better measure to evaluate the influence of ear protectors on the intelligibility of speech.

Guinea pigs were exposed to 10 impulses of either 157-or 163dB peak SPL.The threshold shift recovery was monitored for 30 d, and tympanometric changes and co-chlear hislochemistry were investigated.The results showed that the 157dB level produced a recovey pattern linear to post-exposure log time and no PTS was found.The 163dB level produced a recovery-stop-recovery pattern, showing 13dB threshold shift on the 30th day after exposure.There are no TM perforation in both groups but most of the cochleas showed loss of outer hair cells or reduced activity of succinic dehydrogenase (SDH).

AIM:To establish a fingerprint method of analyzing Xuefu Zhuyu Capsule(Semen Persicae,Radix Angelicae sinensis,Fruclus Aurantii,Rhizoma Chuanxiong,etc.) by HPLC. METHODS: A HPLC in combination with PDA detector was applied with a HiQ C_(18)(4.6 mm?250 mm,5 ?m) column by gradient elution using methanol-1.0% acetic acid solution as the mobile phase.The flow rate was 0.5 mL/min and the detection wavelength was at 260 nm. RESULTS: Thitrty-six common peaks were obtained in the fingerprint of Xuefu Zhuyu Capsule with good separation,six of them were identified as adenosine,paeoniflorin,naringin,hesperidin,neohesperidin and ligustilide by comparing chromatogram with control compounds. CONCLUSION: The HPLC method with good precision and reproducibility can be used for the quality control of Xuefu Zhuyu Capsule.

Objective To fully understand the medicinal plants of Fritillaria L.,the physicochemical properties of starch in two species of Fritillaria L.,F.thunbergii and F.ussurensis.were investigated by means of various analytical methods.Methods The properties of starch in the two different species of Fritillaria L.were compared by X-ray diffraction,scanning electron microscope(SEM) and themogravimetric analysis(TGA).Results The crystal type of starch in the two species of Fritillaria L.was the characteristic B-type which was in consistent with that of potato starch.The degrees of crystallinity of F.thunbergii starch and F.ussurensis starch were about 29.9% and 20.1%,respectively.However,the degree of crystallinity of the potato starch was 44.9%.From the crystallinity degree of the starch in two species of Fritillaria L.,it could be concluded that the content of amylose in F.ussurensis starch was higher than that in F.thunbergii starch.The granule size of the starch in two species of Fritillaria L.ranged from 5 to 40 ?m,which were all smaller than that of the potato.The starch granule in two species of Fritillaria L.was in cycloidal or elliptic-shape.It could be concluded that the thermal stability of the starch in two species of Fritillaria L.was different due to the different structures of different starch in various plants by TGA.Conclusion The physicochemical properties of starch in two different species of Fritillaria L.differ a lot due to their geographical origin.

Along with the progress of Chinese pharmaceutical industry, as well as the development of natural products in the world, the need of medicinal plant resources is increasing, which results in the ruinous destruction of endangered medicinal plants. The field cultivation and wild tending cultivation could not solve all the resource problems and the help with bioengineering technolgy will be needed in this field. Micropropagation could quickly supply the shoots with good quality medicinal plants by two ways, the shoot and root induction through callus or the other is shoot development by somatic embryos. The regenerated shoots could be transferred into the field for the base of field cultivation or tending cultivation. In addition, the active compounds could be produced by the cultivated medicinal plant cells, tissues, or organs in bioreactor, which could decrease the cost at industrial level. In China, the bioengineering technology should be developed and applied to the medicinal plants development, because the most resources to support the whole traditiolal Chinese medicine will be utilized, moreover, in China the most amount of extracts from medicinal plants are used and exported all over the world.

Objective: To investigate the protective effect of adenosine on hearing in acute acoustic trauma and its modulatory action in the cochlea. Methods:Guinea pigs were exposed to 118 dB SPL white noise for 30 min. During the process of exposure, artificial perilymph or artificial perilymph containing 1 mmol/L adenosine was infused into the cochlea through perilymphatic perfusion. Thresholds of compound action potentials (CAP) evoked by click and tone burst were measured before and after noise exposure. Results: Immediately after exposure, the mean threshold shifts evoked by click of the control group and adenosine treated group were (40?6.68) dB and (20?5.70) dB respectively. The threshold shifts evoked by tone burst at 2 8 kHz in the control animals were 32 50 dB, while in the adenosine treated animals, 20 35 dB. There were significant differences between the 2 groups except that at 6 kHz. Two hours after exposure, there was an increase of 4 8 dB at all frequencies in the control group; no changes in the adenosine treated group were found. There were significant differences in threshold shifts between the 2 groups at all test frequencies. Conclusion: Adenosine has protective effect on temporary threshold shift in acute acoustic trauma in guinea pigs. [

Objective To study the chemical constituents in Lobelia chinensis.Methods Isolation and purification were carried out by silica gel,Sephadex LH-20,and preparative HPLC.Their structures were elucidated by spectroscopy and physicochemical properties. Results Twelve compounds were obtained and identified as: cycloeucalenol(Ⅰ),24-methylenecycloartanol(Ⅱ),phytol(Ⅲ),phytenal(Ⅳ),?-amyrin(Ⅴ),adenosine(Ⅵ),n-butyl-?-Dfructofuranoside(Ⅶ),n-butyl-?-D-fructofuranoside(Ⅷ),n-butyl-?-D-fructopyranoside(Ⅸ),n-butyl-?-D-fructopyranoside(Ⅹ),salicin(Ⅺ),and 5-hydroxymethyl furaldehyde(ⅩⅡ).Conclusion Compounds Ⅰ—Ⅳ and Ⅵ—ⅩⅡ are obtained from the plants of Lobelia L.for the first time and compound Ⅴ is obtained from this plant for the first time.

By means of HPLC,the changes of endogenous hormones in the process of releasing dormancy in Fritillaria thunbergii Miq. seeds were determined. The results indicated that the content of GA3 had a process of increase while the content of ABA was reduced in general. The content of IAA showed a downward -plateau-upward-downward curve in the process of releasing dormancy. When the dormancy of the seeds were released attemperatures 8~10℃ and 3~5℃,changing pattern of each of the three endogenous hormones were similar,but the duration spanning each change were different.