[Research on Dry Chemical Detection TechnologyBased on Reflectance Photometry].

In response to the issues of insufficient stability and accuracy in dry chemical detection using reflectance photometry, caused by the divergence and multiple internal reflections of the reflected light signal from the sample and the multilayer dry film test strip, a dry chemical reflectance photometry detection system based on an integrating sphere is designed. Firstly, an integrating sphere device is incorporated to reduce signal divergence and loss, ensuring even detection of the sample's reflected light signal and improving detection stability. Secondly, Light Tools optical simulation analysis is performed, and an integrating sphere detection model is established. Thirdly, the Williams-Clapper equation is employed to correct the error in reflectance density caused by multiple internal reflections, enhancing detection accuracy. Experimental validation demonstrates that the developed integrating sphere-based dry chemical reflectance photometry detection system improves the stability and accuracy of the detection system.

[Effect of electroacupuncture on expression of hippocampal Caspase-3 in rats with cerebral ischemia/reperfusion injury].

OBJECTIVE: To observe the effect of electroacupuncture (EA) on the expression level of Caspase-3, so as to explore its mechanism in inhibiting apoptosis after cerebral ischemia reperfusion. METHODS: SD male rats were randomly divided into sham-operation, model, EA and Caspase-3 inhibitor groups (n=20 rats in each group). The focal cerebral ischemia/reperfusion injury rat model was established by occlusion of the middle cerebral artery. Rats of the EA group received EA at "Hegu" (LI4), "Chize" (LU5), "Zusanli" (ST36) and "Sanyinjiao" (SP6) on the affected side for 20 min. Rats of the inhibitor group were given intracerebroventricular injection of inhibitor Z-DEVD-FMK 5 µg before modeling. The neurological deficit scores (NDS) were assessed by using Longa's method, the infarct size of the brain assessed after staining with 2% triphenyltetrazolium chloride. The apoptosis index of nerve cells were observed by TUNEL staining, PCR and Western blot were used to detect the mRNA and protein expressions of Caspase-3 in the hippocampus, separately. RESULTS: After modeling, the NDS, infarct volume, the apoptosis index of hippocampus CA1 area, and Caspase-3 mRNA and protein expression levels were significantly increased in the model group compared with the sham-operation group (P<0.01). After intervention, the NDS, infarct volume, the apoptosis index, Caspase-3 mRNA and protein expression levels were all significantly decreased in the EA and Caspase-3 inhibitor groups re-levant to the model group (P<0.05). CONCLUSION: EA can improve the neurological function in cerebral ischemia/reperfusion rats, which may be related to its effect in inhibiting of Caspase-3 expression.

[Protective effect of magnesium isoglycyrrhizinate combinated with verapamil on liver ischemia-reperfusion injury after semi-hepatectomy in rats].

OBJECTIVE: To investigate protective effect of isoglycyrrhizinate combinated with verapamil on liver ischemia-reperfusion injury after semi-hepatectomy in rats. METHODS: Male SD rats were randomly divided into five groups: false operation (group A); rats subjected to 50％hepatectomy and 45 min of hepatic ischemia (group B); rats subjected to 50% hepatectomy and 45 min of hepatic ischemia, and treated with isoglycyrrhizinate (group C); rats subjected to 50% hepatectomy and 45 min of hepatic ischemia, and treated with verapamil (group D); rats subjected to 50% hepatectomy and 45 min of hepatic ischemia, and treated with isoglycyrrhizinate and verapamil (group E). Liver function, as well as morphology, SOD activity, FasL, caspase 3, and ß-catenin expression of rats were analyzed. RESULTS: Compared to group B, the levels of serum ALT of group E were significantly lower (P<0.05), SOD activity of liver tissue (98.8±7.1) were significantly higher (P<0.01), pathological changes were milder, FasL gene (1.327±0.193) and protein (0.010 9±0.001 4) expression were significantly lower (P<0.01). Caspase 3 protein expression levels (0.141 0±0.005 3) were significantly lower (P<0.001), ß-catenin protein expression levels (0.079 1±0.008 2) were higher significantly (P<0.01). CONCLUSIONS: Isoglycyrrhizinate combinated with verapamil can effectively reduce rats liver ischemia-reperfusion injury. The protective effect on liver cells may be mediated by inhibiting apoptosis caused by Fas/FasL system, increasing ß-catenin protein expression, promoting liver regeneration and relieving liver peroxidation damage.