Objective To study the impact of vegetation changes on the distribution of Oncomelania hupensis in the marshland and lake regions.MethodsA bottomland from the 14 bottomlands along the Qiupu River in the Guichi District,Chizhou City,Anhui Province was selected,and a 50 m?50 m area of uniform vegetation was choosed as the research field.Low-grass group,boundary-grass group,hay group and control group were designed to represent four types of vegetation's status and the snail density,soil temperature and soil moisture were surveyed half a month after the design.The change of Oncomelania hupensis's distribution due to the vegetation change was analyzed statistically.ResultsThe snail density of the hay group was nearly 0 with high soil moisture and low soil temperature.The snail density of the low-grass group was obviously decreased(32.1/0.1 m2),and the snail density of the boundary group slightly increased,which had no statistical significance compared with the snail density of the control group.ConclusionsOncomelania hupensis moves from the low-grass group to the boundary group after the vegetation is cut down,which changes the distribution of snail.Hay group is the worst environment for Oncomelania hupensis to survive and the method of cut-overlay grass may be used to improve the effect of molluscicide.

Objective To explore a possible method for determining the appropriate sample size of Oncomelania hupensis in the marshland and lake regions. Methods Four bottomlands were selected randomly along the Qiupu River in Guichi District, Anhui Province. Oncomelania snails were surveyed carefully in these bottomlands and brought back to the laboratory to judge whether they were alive or not with mild water. All the data of Oncomelania hupensis were doubly input into the EpiData software and checked for the errors. Repeated sampling was performed in the four databases according to different sample sizes by using SAS software and the corresponding snail density was also calculated. According to the values of sample size and corresponding snail density, sample size-snail density absolutely changing curve and relatively changing curve were drawn to determine the appropriate sample size of snail survey. Results The appropriate sample sizes of snail survey were 40,200,100 and 200 frames in Gutan bottomland, Caizi bottomland, Qiupu bottomland and Ouyang bottomland, respectively. Conclusion Sample size-snail density absolutely changing curve and relatively changing curve could provide some instructions for choosing the appropriate sample size during the process of snail survey in the marshland and lake regions.

Objective To investigate the risk factors of hemorrhagic transformation (HT) following thrombolytic therapy in acute cerebral infarct patients. Methods The clinical data of 246 cases with acute cerebral infarct treated with rt-PA within 4.5 h from the onset were reviewed. According to the results of brain CT imaging after intravenous thrombolysis for 24-36 h, the patients were divided into HT group and non HT group. The factors including age, gender, NIHSS scores, drinking, smoking, hypertension, diabetes, atrial fibrillation. The univariate analysis and Losgistic regression analysis were further assessed. Results The results of univariate analysis indicated that there were no significant differences between the two groups in age, gender, smoking , drinking, time from onset to thrombolysis, diabetes (P > 0.05), but there were significant differences between two groups in NIHSS scores [(14.53 ± 6.06) scores vs.(9.98 ± 6.26) scores, P = 0.000], hypertension [86.1%(31/36) vs.70.0%(147/210), P = 0.046] and atrial fibrillation [63.9%(23/36) vs. 24.3%(51/210), P = 0.000]. Logistic regression analysis showed that NIHSS scores (OR = 1.079, 95% CI = 1.014- 1.147, P = 0.016) and atrial fibrillation (OR=3.298, 95%CI=1.481-7.345, P=0.003) were the risk factors associated with hemorrhagic transformation after intravenous thrombolysis for acute cerebral infarction. Conclusions NIHSS scores and atrial fibrillation are the risk factors associated with HT after thrombolytic therapy in acute cerebral infarct patients.

Objective To analyse effect of rt-PA intravenous thrombolytic therapy on serum levels of neuro-specific endolase, C-reactive protein and fatty acid binding protein in patients with early cerebral infarction.Methods 54 patients who were diagnosed with early acute cerebral infarction in Dalian Municipal Central Hospital were collected.All patients were randomly divided into experimental group and control group,27 cases in each group.Two groups were given conventional treatment,such as reduction of intracranial pressure,improve circulation and nutrition brain cells.Control group was given low molecular weight heparin calcium injection 5000U, one times per 12 h for 7 consecutive days, and experimental group was given rt-PA intravenous thrombolytic therapy on the basis of the control group for 7 consecutive days, post-treatment,the serum levels of NSE, CRP and FABP were detected in all patients.Results Compared with control group post-treatment, the serum CRP,NSE and FABP level was lower in experimental group ( P<0.05).Conclusions The rt-PA intravenous thrombolytic therapy can significantly reduce the serum CRP, NSE and FABP levels in the patients with early cerebral infarction, improve the prognosis of patients.

Objective To investigate the risk of hemorrhagic transformation and the curative effect in patients with atrial fibrillation(AF)treated by intravenous thrombolysis with alteplase after acute cerebral infarct. Methods The clinical data of 246 patients with acute cerebral infarct treated with intravenous alteplase within 4.5 h from the onset were analyzed.According to the presence or absence of AF, the patients were divided into AF group (74 cases) and non AF group (172 cases). The outcomes were the incidence of hemorrhagic transformation within 36 h and the curative effect after 2 weeks. Results The incidence of hemorrhagic transformation in AF group was 31.1%(23/74), in non AF group was 7.6%(13/172),and there was significant difference(χ2=22.917,P=0.000).The effective rate in AF group was 54.1%(40/74), in non AF group was 76.7%(132/172), and there was significant difference (χ2=12.665,P=0.000).Conclusions Patients with acute cerebral infarction combined with AF have a high risk of hemorrhagic transformation and poor prognosis after intravenous thrombolysis.

Purpose To evaluate the image quality improvement of deep learning iterative reconstruction(DLIR)on pediatric head CT images of head injury and to evaluate the performance of DLIR and conventional adaptive statistical iterative reconstruction-veo(ASIR-V)of noise and image texture of CT image in children's head trauma.Materials and Methods A total of 80 cases in Beijing Children's Hospital,Capital Medical University from December 7th to 11th 2020 of children's head low-dose CT were retrospectively selected.Scan voltage was 120 kV.Scan current was 150-220 mA.The raw data were reconstructed into 5 mm thick slice and 0.625 mm thin slice brain window and bone window images.50%ASIR-V and high weight DLIR images(DL-H)were reconstructed,respectively.A 4-point system was used to subjectively evaluate the display of sulcus,brain matter and bone.The number of lesions in each group was counted.The CT value and image noise values of gray matter and white matter were measured,and the contrast to noise ratio was calculated,then measured the blur metric index was measured in the same slice.The differences between the two image reconstruction methods were compared.Results Compared to 50%ASIR-V images,DL-H significantly improved the display ability of the sulcus and ventricles,as well as the display ability of the brain parenchyma(W=5.5-22.2,all P<0.05)in both slice thickness.There was no statistically significant difference in the display ability of the sulcus and ventricles between 5 mm 50%ASIR-V and 0.625 mm DL-H images(W=0.9,2.0,P=0.32,0.05,respectively).In terms of bone display ability,all images could achieve a maximum score of 4.0.A total of 35 lesions were found in 80 patients via 5 mm 50%ASIR-V and DL-H images,including 12 hemorrhagic lesions,1 intracranial gas,9 fractures,and 13 soft tissue swelling.In terms of objective evaluation,the noise level of DL-H images was significantly lower than that of 50%ASIR-V images(t=21.4-35.7,all P<0.05),and there was no statistically significant difference in noise and contrast noise ratio between 5 mm 50%ASIR-V and 0.625 mm DL-H images(t=1.7-2.2,all P≥0.05).The blur metric index showed that DL-H was superior to 50%ASIR-V images(t=6.1,10.0,both P<0.05),and there was no statistically significant difference in blur metric index between 0.625 mm DL-H and 5 mm 50%ASIR-V images(t=2.6,P=0.28).Conclusion DLIR can improve the CT image quality and image texture of children's head trauma,0.625 mm DL-H image quality is close to 5 mm 50%ASIR-V image,which can meet the diagnostic requirements,and possible to further reduce the radiation dose.