Objective To explore the Schistosoma japonicum cercariae collected method and the quantity of cercariae obtained from a great quantity artificial infected snails. Methods In laboratory condition, Oncomelania snails were infected with schistosome miracidia. Sixty days post-infection all snails were divided into 7 shares. Cercariae shed from 1 share snails every day and the number of all shedding days were 40. Cercariae shed from snails were collected with low-velocity centrifuge and the cercariae sediment were weighted. Results One thousand and nine hundred g snails bred for 120 days post-infection, the infection and survival rates were 36. 00% and 51. 58%. Cercariae col-lected were 10. 5 g from 40 days collection. Cercariae quantity of shedding from 1 000 positive snails per day was 0. 257 4 g.

Objective:To investigate the influencing factors for unfavorable outcome of low-grade aneurysmal subarachnoid hemorrhage (aSAH).Methods:A retrospective study was performed. The clinical data of 273 patients with aSAH of World Federation of Neurosurgery (WNFS) grading I and II, admitted to our hospital from April 2017 to March 2021, were collected. According to modified Rankin scale (mRS) scores 3 months after treatment, these patients were divided into favorable outcome group (mRS scores of 0-2) and unfavorable outcome group (mRS scores of 3-6). Statistical methods were used to analyze the clinical and imaging data differences between the two groups and identify the independent influencing factors for unfavorable outcome. Receiver operating characteristic (ROC) curves were drawn to evaluate the predictive values of different independent factors in unfavorable outcome.Results:Among the 273 patients with low-grade aSAH, 45 patients had unfavorable outcome and 228 patients had favorable outcome. Univariate analysis showed that there was significant difference between the 2 groups in age, Fisher grading distribution, proportions of patients complicated with shunt dependent hydrocephalus, with delayed cerebral ischemia, or with intracranial hemorrhage, and WNFS grading ( P<0.05). Multivariate Logistic regression analysis showed that concurrent shunt dependent hydrocephalus ( OR=5.075, 95%CI: 1.705-15.102, P=0.004), age ( OR=1.090, 95%CI: 1.036-1.147, P=0.004), delayed cerebral ischemia ( OR=8.282, 95%CI: 3.447-19.896, P=0.000), and postoperative intracranial hemorrhage ( OR=8.603, 95%CI: 2.332-31.745, P=0.001) were independent influencing factors for unfavorable outcome. ROC curve analysis showed that the optimal diagnostic threshold of age was 65 years, and the areas under ROC curve for delayed cerebral ischemia and age in predicting unfavorable outcome were 0.733 ( 95%CI: 0.653-0.813, P=0.000) and 0.709 ( 95%CI: 0.622-0.796, P=0.000). Conclusion:Low-grade aSAH patients with age≥65, postoperative shunt dependent hydrocephalus, delayed cerebral ischemia, and intracranial hemorrhage are more likely to have unfavorable outcome; age and complicated delayed cerebral ischemia have certain diagnostic value in low-grade aSAH patients.