Spinal cord injury is one of the important field of neuroscience, and neural tract tracing techniques are important research tools. The neural fiber types in the spinal cord are complex, and there are some difference in structures between human beings and animals. This article reviewed different types of neural fibers closely related with spinal cord injury and regeneration, the difference between human beings and animals, and the application of neural tract tracing techniques in the study of spinal cord injury and regeneration.

Objective To explore the value of contrast-enhanced ultrasonography ( CEUS ) breast predictive model in the optimization of BI-RADS classification of breast lesions . Methods A total of 1049 BI-RADS 4 ,5 breast lesions were obtained from 1039 patients in 8 centers . CEUS examination was performed prior to biopsy or surgery . According to the classification of the model ,class 3 ,4A ,4B and 4C were selected as biopsy thresholds ,and the ROC curve was drawn . The diagnostic sensitivity ,specificity , accuracy ,positive predictive value ,negative predictive value and Jordanian index were calculated for the biopsy threshold . The biopsy rate of breast lesions before and after angiography ,cancer detection rate , follow-up cases of malignant risk were compared . Results There were benign lesions 586 ( 55 .9％ ) , malignant lesions 463 (44 .1％ ) in the 1049 breast lesions . The area of ROC with thresholds of 3 ,4A ,4B and 4C were 0 .695 ,0 .838 ,0 .847 and 0 .757 ,respectively ( all P < 0 .01) . Ultrasonography had a certain diagnostic effect on benign and malignant breast lesions . The diagnostic sensitivity ,specificity ,accuracy , positive predictive value and negative predictive value with class 4A after CEUS set as the biopsy threshold were 93 .32％ ,75 .65％ ,82 .75％ ,75 .57％ and 93 .35％ ,respectively ,and the Jordanian index was 0 .690 . When chass 3 after CEUS was set as the biopsy threshold ,the biopsy rate was reduced from 100％ to 76 .74％ ,the detection rate was increased from 44 .23％ to 56 .77％ ,and the risk of cancer was only 0 .67％ in the follow-up cases . When class 4A was set as the biopsy threshold ,the biopsy rate was reduced from 100％ to 55 .58％ after CEUS . The detection rate of cancer increased from 44 .23％ to 74 .44％ . The risk of cancer was 2 .96％ . Conclusions The biopsy rate of breast lesions in category 4 and 5 would be reduced and cancer detection rate of them would be increased after CEUS ,however ,the risk of malignancy in the follow -up cases would be controlled as low as category 3 and 4A in previous BI-RADS . Thus ,CEUS has a good prospect of in optimizing BI-RADS and reducing biopsy rate in unnecessary lesions .

Objective To observe the effect of injecting botulinum toxin type A on muscle tension,disability level and ability in the activities of daily living in patients with post-stroke dystonia.Methods Thirty-two patients with post-stroke dystonia were divided into an observation group (n =16) and a control group (n =15).The patients in the observation group were injected with 200-600 U of botulinum toxin type A in the relevant muscles,while the patients in the control group were given 12 mg diphenhydrazole hydrochloride tablets orally.Before and 2,6 and 12 weeks after the treatment,spasticity,disability and daily living ability were evaluated in both groups using the modified Ashworth scale (MAS),a disability assessment scale (DAS) and the modified Barthel index (MBI).Results After the treatment,the average MAS,DAS and MBI scores of both groups were significantly better than before the treatment.And the average MAS,DAS and MBI scores of the observation group were significantly better than those of the control group.Conclusion Botulinum toxin A injection can significantly improve dystonia and relieve disability among stroke survivors.

Objective To establish a rat liver transplantation model under direct vision of single operator and to explore the effect of different perfusion methods on the quality of the donor liver. Methods On the basis of the "two-cuff method" established by Kamada, the operation details were improved to established the rat liver transplantation model. The recipient rats were divided into two groups according to different perfusion methods, group A (perfusion via abdominal aorta) and group B (perfusion via portal vein). The perfusion effect, operation time, operation success rate, postoperative liver function, liver graft pathological manifestations and survival were compared between the two groups. Results There were more residual red blood cells in sinus hepaticus in group B than in group A after perfusion. Both the donor liver perfusion time and donor operation time were longer in group A than those in group B, and the differences were statistically significant (both P < 0.01). The success rate of operation in group A and group B was 77% and 71%, respectively. At 3 d after liver transplantation in rats, the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and total bilirubin (TB) of the rats in the two groups were significantly higher than normal. At 7, 30 d after operation, compared with group A, the levels of ALT, AST and TB in group B were significantly increased, and the differences were statistically significant (all P < 0.01-0.05). The liver pathological examination showed that the degree of inflammatory reaction in the liver and degree of destruction of liver tissue in group B were more severe than those in group A, but there was no significant difference in long-term survival rate between the two groups. Conclusions Although the perfusion time and donor operation time of rat liver transplantation model were slightly prolonged by means of abdominal aorta perfusion, the perfusion effect was better, which can reduce liver tissue damage after operation and restore liver function to normal levels more quickly.

Objective To evaluate the diagnostic value of contrast-enhanced ultrasound in breast precancerous lesions . Methods Retrospectively analyzed the contrast-enhanced ultrasound model and angiographic predictive model of 465 cases of the A prospective multicenter study of breast nodules contrast-enhanced ultrasound" that led the Sichuan Provincial People′s Hospital from January 2016 to April 2017 ,which included 69 cases of breast precancerous lesions and 396 other types benign lesions ,and the sensitivity ,specificity and accuracy of the diagnosis of breast precancerous lesions were calculated . Results The sensitivity of ultrasound predictive model for the diagnosis of precancerous lesions was 60 .9％ and AUC was 0 .681 . Precancerous lesions mainly showed non-concentricity , increased homogeneity , and increased lesions;other types of benign lesions mainly showed non-centripetal ,high uniformity enhancement and lesion size unchanged . Conclusions Contrast-enhanced ultrasound shows a potential value in the differential diagnosis of precancerous lesions and other types of benign lesions ,that can help clinicians to take early intervention measures for breast precancerous lesions ,but there are still many problems to be solved .

ObjectiveTo explore and analyze the influencing factors of myopia among the primary and middle school students, and to provide an evidence for the prevention and control of myopia in students through the combination of scientific use in electronic products and adherence improvement to outdoor activities. MethodsStratified cluster sampling method was used to select 4 schools in Jiading District, in which all the students in grades 3‒5 of primary school and grades 7‒9 of middle school were enrolled into the study for a questionnaire survey and refraction examination. The χ² test was used to compare the data between the myopic and non-myopic group. Logistic regression analysis was used to analyze the influencing factors of myopia. ResultsThe total myopia detection rate among the primary and middle school students in the industrial zone of Jiading District was 62.8%, with a detection rate of 46.9% for primary school students and 75.6% for middle school students, respectively. Logistic regression analysis showed that middle school (OR=3.639, 95%CI=3.045‒4.349, P<0.001), female students (OR=1.278, 95%CI=1.081‒1.510, P=0.004), the frequency of school desks and chairs was adjusted>1 semester (OR=1.227, 95%CI=1.031‒1.461, P=0.021), the length of time spent on extracurricular tutorial classes for main courses ≥1 hour in a week (OR=1.205,95%CI=1.009‒1.440, P=0.040), parents reduced the length of time that their children spent on exercise (OR=1.205, 95%CI=1.009‒1.440, P=0.040), and parental myopia (OR=2.611, 95%CI=2.157‒3.160, P<0.001) were associated with myopia among the primary and middle school students in the industrial zone of Jiading District. ConclusionThe detection rate of myopia among students in Jiading District was relatively high. More attention should be paid to the effect of school desks and chairs’ adjustment frequency, the length of time spent on extracurricular tutorial classes for main courses, electronic screen exposure time on students’ vision, so as to prevent and slow down the occurrence and development of myopia.