Objective To expand the application of electrochemical immunosensor during deleting aflatoxin B1 in foods and feeds through analyzing impacts of the time of antibody incubation and sample preparation .Methods T he double self-assembly immu-nosensor combined with aflatoxin B1 and carboxylated single-walled carbon nanotubes (SWNTs) was characterized by cyclic volta-mmetry and impacts of the time of antibody incubation and sample preparation methods were investigated .Results The signal in-creased gradually following the increasing time of antibody incubation and reached a plateau at 90 min and sample preparation meth-ods showed a comparatively large impact on results .Additionally ,the crude extractions purified through removing interfering com-pounds by immunoaffinity column could effectively eliminate the interference effects of sample matrix .Conclusion Deleting aflatox-in B1 by electrochemical immunosensor is characterized by various features ,such as fast ,simple and low detection limits .The pres-ent study shows that stability of the electrochemical immunosensor is affected by the time of antibody incubation and sample prepa-ration .

Objective To develop a new type of electrochemical immunosensor for the detection of ochratoxin A (OTA ) . Methods Double layers of self‐assembly immunosensor for the detection of OTA were constructed based on the composite single‐walled carbon nanotubes(SWNTs)/chitosan(CS) membrane immobilized on glassy carbon electrode(GC) .Scanning electron mi‐croscopy(SEM) ,square wave voltammetry and cyclic voltammetry were used to analyze the characterization of the sensor ,then its specificity for detection was studied .Results SWNTs/CS composit membrane could increase the sensitivity of OTA detection sig‐nificantly ,and effectively distinguish the different types of mycotoxins .Conclusion The electrochemical immunosensor developed in the study is easy to operate and could detect OTA rapidly with good specificity and low detection limit .

Abstract: To date, the investigation of the functional composition of Centella asiatica (L.) Urban has been mainly focused on the triterpenoid saponins, with little research on the other compositions. The acetic acid-induced writhing, Eddy's hot plate and formalin tests were employed to investigate the anti-nociceptive effects of madecassic acid (MA). The experiment was divided into normal control group, acetylsalicylic acid (ASA) group, and the MA groups of low (10 mg/kg), medium (20 mg/kg) and high (40 mg/kg) dosage. Meanwhile, the anti-nociceptive effect of MA on the acetic acid and formalin-induced nociceptive models in the absence and presence of NAL (naloxone hydrochloride) was evaluated. To have an insight into the anti-nociceptive mechanisms of MA, the capsaicin- and glutamate-induced paw licking tests were also employed to evaluate the involvement of the vanilloid and glutamatergic systems, respectively. Results showed that MA exhibited good anti-nociceptive activity in the acetic acid-induced writhing test and the second phase of formalin test; the anti-nociceptive effect of MA in both the acetic acid and formalin-induced nociception was not effectively removed by NAL; MA (20 mg/kg and 40 mg/kg) effectively reduced the duration of biting/licking the capsaicin-injected paw with inhibition rates of 29.5% and 64.4%, respectively; MA (20 mg/kg and 40 mg/kg) distinctly shortened the time spent in biting/licking the glutamate-injected paw by 30.9% and 56.1%, respectively. In summary, MA induces significant peripheral anti-nociceptive effect, and the anti-nociceptive activities probably involve the modulation of glutamatergic systems and vanilloid systems (TRPV1) instead of the opioidergic system.

Objective:To explore indicators related to visceral fat index by constructing a random forest model.Methods:In this cross-sectional study, the laboratory measures and body composition analysis records of 617 hospital employees (in-service and retired) who underwent physical examination in Heilongjiang Provincial Hospital Health Management Center from March to September 2021 were selected. The subjects were divided into a training set ( n=411) and a test set ( n=206) with the ratio of 2∶1. A total of 110 predictors were included in the model. The model was constructed with the training set and was evaluated with the test set. The optimal number of nodes and decision trees were selected to evaluate the prediction performance of the optimal model. And the top 10 relatively important factors were selected for further investigation. The 617 participants were further divided in to groups according to the visceral fat index: the normal or high visceral fat index group, and the differences of the top 10 relatively important factors were further compared between the two groups. Results:The optimal number of nodes of the final random forest model was 39 and the number of decision trees was 300. The accuracy, precision, sensitivity and specificity of the model was 83.3%, 73.9%, 89.4% and 78.7%, respectively. The area under the receiver operating characteristic curve and 95% confidence interval of the model was 0.881 (0.832-0.931). The top 10 relatively important factors in the model were body mass index, gender, age, serum uric acid, red blood cell count, monocyte cell count, C-peptide, carcinoembryonic antigen, glycosylated hemoglobin and glutamyl transpeptidase. There were significant differences in the up-mentioned 10 indicators between the subjects with normal and high visceral fat index (all P<0.05). Conclusions:The random forest model built in this study has good performance in predicting visceral fat index, and visceral fat is related with changes in liver function, pancreas function and immune function.

Objective To investigate the detection and clinical significance of Tp-e interval extension of sudden coro-nary death. Methods A total of 502 patients with coronary heart disease were selected, of which 46 patients with sud-den coronary death were assigned to the sudden death group and the other 456 patients were assigned to the survival group. The Tp-e, Tp-e/√RR , heart rate-corrected QT inverval (QTc) and left ventricular ejection fraction of the two groups were compared and the clinical significance of Tp-e interval extension for sudden coronary death was decided. Results Compared to the survival group, the sudden death group had significantly extended Tp-e, Tp-e/√RR and QTc(P<0.05);Compared to the survival group, the sudden death group had significantly reduced LVEF (P<0.05); Tp-e extension was positively correlated to sudden coronary death and QTc(P<0.05). Conclusion The Tp-e interval extended obviously in the patients with sudden coronary death and thus can serve as a predictive risk factor of sudden coronary death.