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Biomedical subjects

M Ai

Publications and source records attributed to M Ai.

At least 55 records · Page 3Linked to original sources
PubMed1991

[Research on the relationship between central acetylcholine and acupuncture analgesia].

The article systematically reported our physiological and biochemical work on the relationship between central acetylcholine and acupuncture analgesia. The results indicate: 1. Acupuncture on acupoints could produce analgesia. 2. Ach contents in cerebrospinal fluids and brain increased under acupuncture analgesia. 3. AChE activities iu brain elevated under acupuncture analgesia. 4. ChE inhibitor reinforced the effects of acupuncture and inhibitor of ACh synthesis could inhibit the effects of acupuncture, which could be reversed by administration of ACh and chlorocholine. M-AChR antagonists could also inhibit the effects of acupuncture. 5. The turnover rate of ACh in diencephalon, caudate nucleus and spinal dorsal horn accelerated when acupuncture analgesia. The discussion was given on the variation of metabolic dynamics in combination with related literature.

Acetylcholine↗
PubMed1990

[The effect of extradural injection of capsaicin on pain threshold and electroacupuncture analgesia of rat].

The present paper is designed to investigate the variation of pain threshold and electroacupuncture analgesia of rat, and to observe the immunohistochemical changes in spinal ganglion and dorsal horn of lumber and sacral segment of spinal cord after extradural administration of capsaicin (100 micrograms/rat). It was found: 1. Obvious decrease of pain threshold 60 mins after injection of capsaicin, and the pain threshold restored nearly to the level of pre-treatment at 90 mins of post-treatment of capsaicin. 2. Apparent elevation of pain threshold on 1st-15th day after injection of capsaicin. 3. The efficiency of electroacupuncture analgesia 7th day after injection of capsaicin was obviously weaker than that of pre-treatment of drug and that of solvents treatment in the animals of control group. 4. The SP-LI, ENK-LI and FRAP were all weakened in dorsal horn of spinal cord 1h after capsaicin treatment. However, on the 7th day, with the exception of decrease of SP-LI and FRAP, the ENK-LI in dorsal horn was strengthened and the activity of FRAP in spinal ganglionic cells of B type disappeared. The foregoing results indicated that the metabolism and function of C fibers of primary afferent especially the SP containing nerve and those of ENK-containing neurons could be influenced by the extradural injection of capsaicin. And the primary afferent C fiber (including the SP containing nerve) may play important roles in the input of the informations of pain, and needling, as well as in the acupuncture analgesia.

Acupuncture Analgesia↗
PubMed1990

[Bending behavior of superplastic titanium alloy for denture base].

The mechanical behavior of the Ti-6A1 4V alloy denture base made by superplastic forming was studied using various bending tests. The bending strength of the Ti-6A1-4V alloy plate made by superplastic forming was as strong as that of the casting Co-Cr alloy plate with the same thickness. The bending strength of the superplastic forming plate with channels was higher than that of the plain plate. Increase in the arch curvature of the plate decreased the strength, because increase in the arch curvature of the plate decreased the thickness of the superplastic forming plate. Similar results were obtained for the clinical models. The appropriate original thickness for superplastic forming denture base was derived empirically from the experimental values for depth of palate.

Chromium Alloys↗
PubMed1989

[Influence of tooth contacts on masseter and temporal muscle activity. 1. Total activity and its ratio to maximum biting activity in intercuspal position (IP ratio)].

14 natural dentitioned subjects with no signs of TMJ disorders, aged 19-58, were used in this study. They were divided into three groups according to their occlusal guidance. One is canine guidance group (CG group), the other is group function group (GF group), and the last is group having non-working side contacts (FB group). All subjects were asked to perform maximum biting in 1) intercuspal position (IP), 2) right lateral position (rLP), 3) left lateral position (lLP), 4) retruded position (RP), and 5) protruded position (PP). EMG recordings of right and left masseter, anterior and posterior temporal muscles from pairs of surface electrodes were taken in each occluded position. The results were as follows: 1) Total integrated EMG activity of FB group was approximately equal in any occluded position, whereas that of CG and GF group varied from position to position. 2) EMG patterns in rLP and lLP of CG group were obviously different from those of GF group. Ratio to maximum biting in IP of CG group in rLP and lLP were significantly small, approximately half of GF group.

Adolescent↗
PubMed1989

[Application of superplastic titanium alloy for denture base--Part 1. Adaptability of the titanium alloy denture base].

The adaptability of the upper complete denture base made from superplastic alloy 90Ti-6A1-4V was investigated by measuring the space between the master model and the denture base. The denture bases showed a high adaptability with the space less than 0.1 mm, whereas after curing resin for denture, it became worse especially with the heat-curing resin. In addition, the thinnest area of the denture base was observed at the middle of the plate with 38% reduction in thickness, and distortion of the base plate of 0.55mm thickness by curing resin was found to be nearly the same as that of type 304 stainless steel plate of 0.50 mm thickness.

Dental Alloys↗
PubMed1989

[Superplastic forming of titanium alloy denture base].

Ti-6Al-4V alloy has both excellent biocompatibility and superior mechanical properties. This Ti-6Al-4V can be deformed greatly and easily at the superplastic temperature of 800 degrees C to 900 degrees C. The superplastic forming of Ti-6Al-4V was made to apply to fabrication of denture base. Almost the same procedure as for dental casting mold was employed in producing the superplastic forming die by the improved phosphate bonded investment. In the pressure vessel of heat resistant alloy, Ti-6Al-4V plate was formed superplastically on the die by argon gas pressure at 850 degrees C. The fit of superplactic forming Ti-6Al-4V denture base was better than that of casting Co-Cr alloy denture bases. The Ti-6Al-4V alloy might react a little with the die. Because micro Vikers hardness of the cross-section did not go up too much near the surfaces. Even just after being formed, the surfaces were much smoother than that of Co-Cr alloy casting. The tensile strength and yield strength of superplastic forming Ti-6Al-4V were higher than those of Co-Cr castings. The elongation was about 10%. These results show that superplastic forming of Ti-6Al-4V would be suitable for a denture base.

Dental Alloys↗