Establishment of hydride generation atomic fluorescence spectrometry for the determination of arsenic and selenium in hair / 中华地方病学杂志

Objective To establish a method for simultaneous determination of arsenic and selenium in hair by hydride generation atomic fluorescence spectrometry.Methods The A and B of the hair samples were digested via the wet method,and the arsenic and selenium contents were determined simultaneously with a dual channel atomic fluorescence spectrophotometer.Standard blank solution was continuously determined for 11 times,the detection limit was calculated according to the blank solution three times the standard deviation.Hair samples A and B were continuously determined for 11 times,and the precision was determined according to the coefficient of variation (CV).The hair samples C and D were did 11 times of standard addition experiment,the standard added was close to the sample low value.The accuracy was determined by the standard recovery rate.Results The lowest detection limits of arsenic and selenium were 0.081,0.036 μg/L,the precisions of arsenic and selenium in sample A were (0.694 9 ± 0.024 2) and (1.930 2 ± 0.098 5) μg/g,the CV were 3.54％ and 5.09％.The precisions of arsenic and selenium in sample B were (6.212 2 ± 0.137 3) and (8.282 2 ± 0.266 8) μg/g,the CV were 2.21％ and 3.22％;the recovery rates of sample C of arsenic and selenium were 96.30％ ～ 110.00％ and 94.80％ ～ 110.00％;the recovery rates of sample D of arsenic and selenium were 93.63％ ～ 108.20％ and 97.03％ ～ 108.34％.Conclusions The method using hydride atomic fluorescence for determination of arsenic and selenium in the hair has been successfully established.This method is simple and easy to operate,with high sensitivity and good accuracy and precision,high recovery,less matrix interference,and less reagent consumed etc.It is worth promoting in prevention and control of endemic diseases.

Establishment of rat models with altered anterior guidance and observation of histological changes in temporomandibular joint synovium / 华西口腔医学杂志

<p><b>OBJECTIVE</b>This study aims to establish a stable animal model with altered anterior guidance and investigate histological changes on temporomandibular joint (TMJ) synovium in rats.</p><p><b>METHODS</b>Thirty-two rats were divided into four groups, namely, control group, anterior-guidance-deficient group (T1), and anterior guidance inclined up to 15 degree (T2) and 30 degree (T3) groups. Metal crowns that add 15 and 30 degrees to the palatal side were cemented to the incisors of maxilla to increase the inclination of anterior guidance. The low-speed diamond wheel shorts for both upper and lower incisors of rats were applied to avoid contact between anterior teeth in all direction, thus establishing an anterior guidance deletion model. TMJ joints on one side of two animals in each group were harvested after 3, 7, 14, and 28 days. Pathological changes were investigated in the TMJ synovium using hematoxylin-eosin (HE) staining.</p><p><b>RESULTS</b>The weight of T1 decreased briefly at first, and then increased slightly (P<0.05). The weight of T3 obviously reduced and then slowly increased, but remained below the initial weight (P<0.05). T3 manifested obvious synovial lining proliferation and vascular dilation (P<0.05).</p><p><b>CONCLUSIONS</b>The rat model of anterior guidance inclined up to 30 degree could imitate the pathological features of TMJ synovium with excessive increase in anterior guidance. A higher inclination of anterior guidance might cause more damage of TMJ synovium. The effect of anterior guidance deletion on TMJ synovium is yet to be determined.
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A Preliminary Research on the Efficacy and Toxicity of Yunaconitine and 8-deacetyl- yunaconitine Isolated from the Processed Products of Aconiti Knsnezoffii Radix / 中国中医药信息杂志

Objective To conduct comparative study on the analgesic and anti-inflammatory effects as well as the acute toxicity of yunaconitine and 8-deacetyl-yunaconitine isolated from the processed products of Aconiti Knsnezoffii Radix.Methods The methods of hot plate test and writhing test were used to evaluate the analgesic effect. Anti-inflammation action was observed by the models of auricle swelling caused by dimethylbenzene. LD50 was determined by the method of Bliss.Results Yunaconitine and 8-deacetyl-yunaconitine have analgesia effect on the pain caused by hot-plate, but there were no statistically significant difference. The pain caused by acetic acid had obvious analgesic action. High and low dose of yunaconitine could significantly reduce the number of mice body torsion and extend the incubation period of pain in mice. The effect of 8-deacetyl-yunaconitine was remarkable only in the high dose. Compared with solvent group, there were little differences in inhibiting effect of auricle swelling caused by dimethylbenzene, and anti-inflammatory action was not exact. The poisonousness of yunaconitine was nearly 20 times of 8-deacetyl-yunaconitine.Conclusion Yunaconitine and 8-deacetyl-yunaconitine may be the analgesic medicine for peripheral analgesic effect. The poisonousness of 8-deacetyl-yunaconitine is less than yunaconitine, the effect is remarkable to the pain caused by acetic acid, and the security is high.