Objective To identify the species of Biomphalaria snails collected in Shenzhen reservoir,based on the mitochondrial 16S rDNA sequences.Methods The 16S rDNA fragments were amplified by PCR from the genome DNA of Biomphalaria snails,and inserted in plasmid pMD-18T for sequencing.The sequence of 16S rDNA fragment and its phylogenetic relationships with those of other species of Biomphalaria snails were analyzed with BLAST and MEGA4 software.Results The amplified 16S rDNA fragment of the Biomphalaria snails was about 466 bp in length.As aligned with the corresponding sequences of the related Biomphalaria species,the identity of nucleotides was 99％ with 1 isolate of Biomphaltria straminea (B.straminea),98％ with 3 isolates of B.kuhniana,95％ with 1 isolate of B.intermedia,and 94％ with 1 isolate of B.edisoni.Based on the 16S rDNA sequence,the results of phylogenetic analysis with neighbor-joining (NJ) and unweighted pair-group method with arithmetic means (UPGMA) indicated that the snails had close genetic relationships with the B.straminea isolate (Genbank accession NO.AY030213.1) Conclusion The Biomphalaria snails collected in Shenzhen reservoir could be classified as B.straminea based on the characteristics of 16S rDNA sequence.

Objective To explore the application effect of based-learning problem (PBL) combined with role playing method(playing teaching role,RPT)in clinical practice teaching of skin diseases. Methods 112 clinical undergraduate interns were randomly divided into experimental group (PBL teaching combined with RPT teaching group, n=56) and the control group (PBL teaching group, n=56). After the internship, clinical probation theory examination, clinical skills assessment and questionnaire survey were used to evaluate the two teaching modes,using SPSS 13.0 software for statistical analysis of the data. Results The results showed that theory examination and clinical skills examination scores in the PBL+RPT group were significantly higher than the PBL group, i.e. (74.29±3.17) vs. (66.14±2.17); (16.66±1.11) vs. (14.50± 1.51), and there were statistically significant differences. The survey showed that the experimental group was better than the control group in learning interest, doctor-patient communication ability and humanistic concern. Conclusion The teaching mode of PBL+ RPT improved the students' enthusiasm for learning, cultivated and improved the humanistic quality, clinical thinking and practical ability of medical and ob-tained the satisfactory teaching effect,It will has a good application prospect.

Objective:To investigate the effect of citric acid-induced cough on swallowing function and serum substance P in stroke patients with early tracheotomy.Methods:Forty-nine post-stroke tracheotomy patients admitted to the Department of Neurosurgery at the First Affiliated Hospital of Soochow University from January 2018 to July 2019 were selected as study subjects. They were divided into intervention group ( n=24) and control group ( n=25) using the random digit table. The control group was subjected to routine nursing, while the intervention group was given citric acid to induce cough based on routine care. The intervention time was 1 week. The swallowing function and serum substance P levels were compared between the two groups before and after the intervention. Results:After the intervention, 45.8% (11/24) of the patients in the intervention group were assessed as having "strong" swallowing function, compared to 28.0% (7/25) in the control group, with a statistically significant difference in swallowing function between the two groups ( Z= -2.22, P<0.05), and the level of substance P in the intervention group was (283.40 ± 134.82) ng/L, significantly higher than that of the control group (203.59 ± 126.16) ng/L ( t=2.14, P<0.05). Conclusions:Citric acid-induced cough helped stroke patients with early tracheotomy to produce effective swallowing action and up-regulate substance P in serum to promote recovery of swallowing function.

With the advent of an aging society,Alzheimer's disease(AD)has gradually become a major ailment affecting the elderly.AD is a neurodegenerative disorder associated with cognitive impairments.In AD patients,brain network connections are disrupted,and their topological properties are also affected,leading to the disintegration of anatomical and functional connections.Anatomical connections can be tracked and evaluated using structural magnetic imaging(MRI)and diffusion tensor imaging(DTI),while functional connections are detected through functional MRI to assess their connectivity status.This review incorporates the findings of previous scholars and summarizes the current research of AD.It mainly discusses the imaging characteristics of large-scale brain network changes in AD patients,so as to provide researchers with scientific and objective imaging markers for AD prediction and early diagnosis,as well as future research.

Objective:To analyze the characteristics of lung function in patients with spinal muscular atrophy (SMA) to provide evidence for multidisciplinary management of SMA.Methods:A total of 30 patients with SMA treated in the SMA multidisciplinary clinic of the Children′s Hospital, Zhejiang University School of Medicine from July 2019 to March 2021 were enrolled, including 1 child with type I, 18 patients with type Ⅱ and 11 children with type Ⅲ.There were 17 males and 13 females; the age ranged from 4 years to 21 years and 10 months old.A retrospective study was conducted to analyze the clinical features, spinal imaging findings and lung functions of patients with different clinical types of SMA and explore the factors influencing the lung functions of patients with SMA.Pulmonary function was measured by forced expiratory flow-volume curve.Forced vital capacity (FVC), forced expiratory volume in one second (FEV 1), FEV 1/FVC and peak expiratory flow (PEF) were measured.The results were expressed as the percentage of the measured value to predicted value.The Cobb angle was measured to evaluate scoliosis. Pearson correlation analysis and multiple linear regression analysis were used to evaluate the relationship between lung function and age and Cobb angle in patients with type Ⅱ SMA. Pearson correlation analysis and univariate linear regression analysis were used to evaluate the relationship between Cobb angle and age in patients with type Ⅱ SMA. Results:Pulmonary function in 1 type I patient showed decreased FVC and FEV 1; Among 18 patients with type Ⅱ, 14 cases had abnormal lung function (77.8%): FVC decreased in 12 patients (66.7%), FEV 1 decreased in 10 patients (55.6%), PEF decreased in 12 patients (66.7%). Among 11 patients with type Ⅲ, one had decreased FVC (9.1%). FVC, FEV 1 and PEF of patients with type Ⅱ were significantly lower than those of patients with type Ⅲ [(62.4±31.8)% vs.(90.8±11.0)%, (66.3±33.3)% vs.(97.8±9.9)%, (65.3±30.1)% vs.(98.6±21.1)%, all P<0.01]. Pearson correlation analysis showed that FVC of patients with type Ⅱ SMA was correlated with age and Cobb angle ( r=-0.864, -0.865, all P<0.001), FEV 1 was correlated with age and Cobb angle ( r=-0.878, -0.863, all P<0.001), PEF was correlated with age and Cobb angle ( r=-0.831, -0.783, all P<0.001), and Cobb angle was related to age ( r=0.922, P<0.001). Multiple linear regression analysis indicated that FVC of patients with type Ⅱ SMA was linearly correlated with Cobb angle ( R2=0.748, P<0.001), FEV 1 was linearly correlated with age ( R2=0.770, P<0.001), PEF was linearly related to age ( R2=0.690, P<0.001). Univariate linear regression analysis revealed that Cobb angle of patients with type Ⅱ SMA was linearly related to age ( R2=0.851, P<0.001). Conclusions:FVC, FEV 1 and PEF may decrease in patients with SMA.The degree of lung function damage is different in different types of SMA patients.With the increase of age, Cobb angle increases and FVC, FEV 1 and PEF decrease in patients with type Ⅱ SMA.Understanding the factors influencing the pulmonary function damage in patients with SMA is conductive to carrying out individual multidisciplinary management.