BACKGROUND:Neural stem cel s with self-proliferation and differentiation potential are the ideal seed cel s for central nervous tissue engineering. Although col agen and silk fibroin as biological scaffold materials have been widely used, both of them used alone have certain shortcomings. Is it possible to combine the two materials to build a novel neural tissue-engineered scaffold? What is the effect of this novel scaffold on the growth and differentiation of neural stem cel s? OBJECTIVE:To observe the growth and differentiation of neural stem cel s seeded onto the novel composite scaffold. METHODS:The rat embryonic neural stem cells were inoculated onto new composite scaffolds, and then, their growth and differentiation were observed by light microscopy and scanning electron microscopy. Neural stem cells were cultured in conventional suspension culture as control group. Cell counting kit-8 assay was used to detect viability of neural stem cells in the two groups. Three-dimensional composite scaffolds carrying neural stem cells were slic ed into paraffin sections to observe the growth and differentiation of neural stem cells by hematoxylin-eosin staining and immunofluorescence staining. RESULTS AND CONCLUSION:Neural stem cel s cultured on the new composite scaffold grew and differentiated wel , and interconnected synapses were observed. Cel counting kit-8 assay showed that neural stem cel s on the scaffold grew wel , and the cel viability was significantly higher in the composite scaffold group than that in the control group (P<0.05). Hematoxylin-eosin staining and immunofluorescence staining of paraffin sections further provided evidence for good growth and differentiation of neural stem cel s on the scaffold. These results indicate that the novel composite scaffold with good biocompatibility benefits the growth and differentiation of neural stem cel s, promising a favorable application prospect.

BACKGROUND:The traditional method of preparing tissue-engineered conduit has the defects of complex shape manufacturing and uncontrolable inner space structure, which cannot meet the requirements of some micro-catheters.
OBJECTIVE:To prepare a bionic spinal catheter and analyze its performance.
METHODS:The data model of the conduit was established using Solid Works software, and platform scan path was generated onthree-dimensionalprinter to produce the bionic spinal catheter with fibroin and colagen as raw materials. Then the water absorption, porosity, mechanical properties and celular compatibility of the conduits were detected. Next, the conduits were implanted into the subcutaneous tissue of rats and taken out at 1, 2, 3 and 4 weeks after surgery, respectively, to observe the degradation.
RESULTS AND CONCLUSION:The porosity of the conduit was (53.6±1.0)%, the water absorption was (1347±19.4)%, and the compression modulus was (0.60±0.12) MPa. The micropores distributed uniformly with different size ranging from 10 to 240 μm. Spherical or fusiform stem cels survived in the pores and densely adhered to the conduit with pseudopodia. The degradation rate ofthe conduit was 20%, 59%, 74%and 100% at 1, 2, 3 and 4 weeks after surgery, respectively. These findings indicate that the artificial bionic spinal catheter has good biocompatibility and degradability.

Objective:To explore the serum levels of copper and zinc and the application value of the ratio in assessing disease activity in patients with inflammatory bowel disease (IBD).Methods:From March 2019 to April 2020, 200 patients with IBD hospitalized at the Department of Gastroenterology of the First Affiliated Hospital of Anhui Medical University were selected by prospective random direct sampling method, including 100 patients with Crohn′s disease (CD) and 100 patients with ulcerative colitis (UC). The Crohn′s disease activity index (CDAI) and the modified Mayo score were used to evaluate the disease activity of CD patients and UC patients. In the same period 100 healthy individuals in the routine physical examination were selected as healthy control group. The serum levels of copper and zinc of the healthy control group, the CD group and the UC group were determined by atomic absorption spectrometry. The levels and the ratio of serum copper to zinc of three groups were compared. The ratio of serum copper to zinc of CD patients and UC patients with different disease activity were compared. The correlation between the ratio of serum copper to zinc and IBD activity indexes were analyzed, which included fecal calprotectin (FC), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), CDAI and Mayo score. Receiver operating characteristic curve was drawn to analyze the value of the ratio of serum copper to zinc, CRP and ESR in predicting disease activity of patients with IBD. Independent sample t test, least significant difference- t test and Pearson correlation analysis were performed for statistical analysis. Results:The serum copper levels and the ratio of serum copper to zinc of the CD group and the UC group were both higher than that of the healthy control group, however the serum zinc levels were lower than that of the healthy control group ( (32.27±7.69) and (29.80±9.68) mol/L vs. (20.16±6.67) mol/L; 2.81±1.57 and 2.29±1.09 vs. 0.68±0.36; (14.64±7.11) and (15.65±8.17) mol/L vs. (34.29±16.40) mol/L), and the differences were statistically significant ( t=2.81, 5.87, 1.47, 7.21, 1.73 and 2.56, all P<0.05). Among CD patients, the the ratio of serum copper to zinc of patients at remission stage (29 cases), mild activity stage (23 cases), moderate activity stage (30 cases) and severe activity stage (18 cases) was 2.61±1.43, 2.75±1.35, 3.15±2.37 and 4.17±1.77, respectively, and the ratios of serum copper to zinc of patients at mild activity stage, moderate activity stage and severe activity stage were all higher than that of patients at the remission stage, and the differences were statistically significant ( t=3.41, 7.92 and 5.84, all P<0.05). There were statistically significant differences in the ratios of serum copper to zinc between patients at mild activity stage and moderate activity stage, severe activity stage, and between patients at moderate activity stage and severe activity stage ( t=5.82, 6.23 and 3.45, all P<0.05). Among UC patients, the ratio of serum copper to zinc of patients at remission stage (10 cases), mild activity stage (30 cases), moderate activity stage (45 cases) and severe activity stage (15 cases) was 1.52±0.44, 1.74±0.58, 2.38±0.83 and 3.80±1.19, respectively, the ratio of serum copper to zinc of patients at moderate activity stage was higher than that of patients at remission stage and mild activity stage, and the ratio of serum copper to zinc of patients at severe activity stage was higher than those of patients at remission stage, mild activity stage and moderate activity stage, and the differences were statistically significant ( t=7.92, 5.83, 3.21, 9.54 and 2.83, all P<0.05). There was no statistically significant difference in serum copper to zinc ratio between patients at remission and at mild activity stage ( P>0.05). The ratio of serum copper to zinc of CD patients was positively correlated with FC and CRP ( r=0.697 and 0.586, P=0.014 and 0.001), however was not correlated with ESR or CDAI score (both P>0.05). The ratio of serum copper to zinc of UC patients was positively correlated with FC, ESR and Mayo score ( r=0.488, 0.452 and 0.331, P=0.001, P<0.01 and P=0.041), however was not correlated with CRP ( P>0.05). The cut-off value of the ratio of serum copper to zinc, CRP and ESR for the diagnosis of CD activity was 1.76, 8 mg/L and 20 mm/1 h, respectively. Among them, ESR was the most effective in the diagnosis of CD activity with an area under the curve (AUC) value of 0.830, and to the sensitivity and specificity was 69.0% and 86.2%, respectively. The cut-off value of the ratio of serum copper to zinc, CRP and ESR for the diagnosis of UC activity was 1.63, 8 mg/L and 20 mm/1 h, respectively; among which the the ratio of serum copper to zinc had the highest efficacy in the diagnosis of UC activity, with an AUC value of 0.862, sensitivity and specificity of 73.0% and 90.9%, respectively. Conclusion:The the ratio of serum copper to zinc is correlated with the disease activity of IBD, which may become a new auxiliary indicator for the evaluation of disease activity.

Objective: To investigate fast food consumption behaviors among 4th and 5th grade primary school students in agricultural and pastoral areas in Qinghai Province, and to provide scientific basis for nutrition education and intervention measures for school age children in agricultural and pastoral areas. Methods: Using multi stage stratified cluster random sampling method, a total of 969 fourth and fifth grade students were selected from 10 primary schools in 4 counties and districts in 3 cities of Haidong City, Hainan Prefecture and Haixi Prefecture from Qinghai Province. Self administered questionnaires were used to investigate the fast food consumption behaviors of participants. Results: The proportions of senior primary school students in agricultural and pastoral areas of Qinghai Province who had consumed western fast food and traditioal fast food in the past week were 45.8% and 75.6%, respectively, with statistically significant differences ( χ 2=290.24, P <0.05). The times of traditional fast food consumption in the past week among boarding students were higher than that of non boarding students( Z =6.44,5.84, P <0.05). The main reasons for senior primary school students in agricultural and pastoral areas of Qinghai Province to choose to consume western fast food were that it was delicious (84.7%), nutritious (62.6%), clean and hygienic (57.4%), and a better environment (57.0%). The top 4 reasons for chousing Chinese fast food were yummy(83.8%),nutritious(82.8%),clean and healthy(67.4%),and good environment(53.5%). Among the surveyed primary school students, 64.7% believed that diet structure of Chinese fast food was reasonable, 43.0% believed that the nutritional value of Chinese fast food was high, and 39.4% believed that the energy content of western fast food was high. Conclusion Fast food consumption is a common dietary behavior of senior primary school students in agricultural and pastoral areas of Qinghai Province. Relevant departments should strengthen the nutrition education related to fast food, promote the dissemination of health knowledge, enable students to develop a good lifestyle and reduce fast food consumption.

Objective: To study the consumption of beverages among senior primary school students in rural and pastoral areas of Qinghai Province, China, in order to provide evidence for the development of nutrition and intervention strategies. Methods: A multi stage stratified cluster random sampling method was employed to select 969 primary school students in grades 4 and 5 from 10 schools in Hainan Autonomous Prefecture, Haixi Autonomous Prefecture and Haidong City. All participants completed a questionnaire survey on daily beverage consumption. The Chi square test was performed to compare differences in reported rates of beverage consumption among students in different groups. Results: The proportion of students who consumed beverages at home, school and elsewhere were 96.9%, 64.5% and 84.9%, respectively. The most popular beverages consumed at home were milk and yogurt ( 63.1 %), tea water (53.0%), and tea drinks (52.4%). The most popular beverages consumed at school were tea(29.8%), milk and yogurt (27.8%) and tea drinks (18.4%), while the most popular beverages consumed in other places were tea drinks ( 42.0 %), carbonated drinks (38.1%) and milk and yogurt (35.0%). The top five reasons for choosing a given beverage were taste delicious (81.2%), nutritious (57.6%),healthy and clean(52.6%),many students like to drink(39.6%),family members often drink(37.7%). Conclusion The consumption of beverages was popular among students, and sugared beverages represented a large proportion of the beverages consumed. Therefore, there is an urgent need to improve the food environment and provide effective nutrition education for students, so as to encourage the consumption of healthy beverages and cultivate healthy eating behaviors.

Objective: To understand the current situation regarding snack food consumption among grade 4 and grade 5 primary school students in agricultural and pastoral areas of Qinghai Province, China, and to provide a scientific basis for nutrition education and intervention strategies. Methods: Multistage stratified cluster random sampling was employed. The research included 969 fourth and fifth grade students were selected from 10 primary schools in four counties and districts of three cities in Haidong City, Hainan Prefecture and Haixi Prefecture in Qinghai Province. The self report questionnaire method was used to investigate the current status regarding snack food consumption in this population. Results: The proportion of students who consumed snack food at home, school and elsewhere were 98.2%, 88.5% and 75.4%, respectively. Male students reported a lower rate of snack consumption at school than female students ( χ 2=9.66). The fifth grade students reported a higher rate of snack consumption at home and other places than the fourth grade students ( χ 2=10.31, 6.77). The reported rate of snack consumption of students in the rural was higher than that in the county( χ 2=6.03,100.53, 24.77). The reported rate of snack consumption of boarding students at home was lower than that of non-boarding students ( χ 2=7.22), while the reported rate of snack consumption at school was higher than that of non-boarding students ( χ 2=9.04）（ P <0.01). The most popular snacks consumed at home included fruits and vegetables, cereals and nuts (76.9%, 67.2%, 63.7%), while the most popular snacks consumed at school were fruits and vegetables, cereals and candies (45.1%, 36.9%, 24.4%). The most popular snacks consumed in other settings included ice cream, candies and beverages(54.7%, 51.6%, 42.9%). The top three reasons for snacking were that snacks were regarded as delicious, healthy/nutritious and clean (76.9%, 65.5% and 59.0%, respectively). Conclusion Snacking is popular among students, although many snacks are unhealthy. Therefore, there is a need to improve food environments and nutrition education, so as to help students to choose healthy beverages and adopt healthy eating behaviors.

Objective: To examine breakfast consumption among primary school students in grades 4 and 5 in Qinghai Province, China, and to provide evidence for nutrition education and intervention strategies. Methods: We used a multistage stratified cluster random sampling method to select the participants. A total of 969 students were selected from 10 primary schools in four counties and districts of three cities, namely Haidong City, Hainan Prefecture and Haixi Prefecture in Qinghai Province. A self rated questionnaire was administered to investigate breakfast consumption. Results: The proportion of students who consumed breakfast 5 to 7 times per week, 3 or 4 times per week, and 1 or 2 times per week were 82.0%, 9.7%, and 6.7%, respectively, while 1.5% never ate breakfast. In descending order, the breakfast food types consumed were cereals and tubers; milk, legumes and nuts; vegetables and fruits; fish and poultry; and meat and eggs (84.1%, 69.8%, 66.8%, and 37.7%, respectively). The proportion of vegetables and fruits in the breakfast of grade 5 students was higher than that of grade 4 students( χ 2=4.81, P = 0.03 ), the proportion of fish, poultry,meat and eggs in county urban areas was higher than that of students in rural( χ 2=6.94, P =0.03), while the proportion of vegetables and fruits in urban areas was lower than that of students in suburban areas( χ 2=53.33, P <0.01). The proportion of breakfast food containing fish,poultry,meat and eggs of boarding students was higher than that of non boarding students( χ 2=41.26, P <0.01), while the proportion of breakfast food containing vegetables and fruits, milk & legumens & nuts was lower than that of non-boarding students( χ 2=21.11, 4.41, P <0.01). A total of 44.8% of students had a poor quality breakfast, and only 16.3% had a good quality breakfast. Moreover, 47.5% of breakfasts were prepared by mothers, followed by the school canteen which prepared 29.9%. Except for students in different grades, there were statistically significant differences in the distribution of breakfast preparers in other groups( P <0.05). Conclusion In Qinghai Province,breakfast skipping is observed in some senior primary school students, and the quality of breakfast is poor. Diet and nutrition education should be provided for students, parents, and school canteen staff to improve the frequency and nutritional quality of children s breakfasts.

Objective: To understand the current situation of food intake frequency among schoolage children in agricultural and pastoral areas of Qinghai Province, and to provide a scientific basis for local education departments and schools to formulate scientific nutrition improvement plans and measures. Methods: A multi stage stratified cluster random sampling method was used to select 969 fourth and fifth grade primary school students from 10 primary schools in Hainan Autonomous Prefecture, Haixi Autonomous Prefecture and Haidong City. All the participants were investigated with a questionnaire survey of dietary behaviors. Results: For the fourth and fifth grade primary school students, the highest proportion of "eaten almost every day" were cereal and tuber ( 84.3 %) and fruits (44.6%), and the highest proportion of "barely eaten" was aquatic product (68.1%) and nutritious supplementary (45.9%). The intake of livestock meat and poultry, fishery products, beverages and nutritional supplements of boys was higher than that of girls（ Z =-2.46，-2.46，-2.43，-2.37， P ＜0.05）. The intake of livestock meat and poultry and snacks of fifth grade students was higher than that of fourth grade students, while the intake of fishery products was lower than that of fourth grade students（ Z = -2.66 ，-4.33，-2.65， P ＜0.05）. Conclusion The frequency of food intake varies among students of differences genders, grades, areas, boarding situation and urbanities. Relevant departments should improve nutrition improvement plans for school age children with different characteristics. Schools and families should carry out nutrition education works to cultivate healthy eating behaviors of students.