The roots of Glycyrrhiza uralensis are widely used in Chinese medicine for their action of clearing heat, detoxicating, relieving cough, dispelling sputum and tonifying spleen and stomach. The reason why Glycyrrhiza uralensis has potent and significant actions is that it contains various active secondary metabolites, especially glycyrrhizic acid. In the present study, we cloned the cDNA coding 3-hydroxy-3-methylglutary CoA reductase (HMGR) involved in glycyrrhizic acid biosynthesis in Glycyrrhiza uralensis. The corresponding cDNA was expressed in Escherichia coli as fusion proteins. Recombinant HMGR exhibited catalysis activity in reduction of HMG-CoA to mevalonic acid (MVA) just as HMGR isolated from other species. Because HMGR gene is very important in the biosynthesis of glycyrrhizic acid in Glycyrrhiza uralensis, this work is significant for further studies concerned with strengthening the efficacy of Glycyrrhiza uralensis by means of increasing glycyrrhizic acid content and exploring the biosynthesis of glycyrrhizic acid in vitro.

Objective: To understand the environmental sanitation situation of rural schools in different geographical areas of Shaanxi, and to provide scientific basis for improving hygiene and sanitation in Chinese rural schools. Methods: Each year during 2016 to 2018, 150 townships in 30 counties of rural areas were randomly selected in various districts and cities throughout the province. In each township one junior high school and one elementary school were randomly selected, and the data was obtained through resource access, interviews, and on-site observations. The data was statistically analyzed and evaluated according to the northern, central and southern regions. Results: The differences of drinking ways among students in the schools were of statistical significance(χ2=25.89,P<0.01). The major drinking water method of students in the monitoring schools of the three regions all was providing boiled water, accounting for 56.16%, 65.88%, 50.39%, all of which have direct drinking unboiled water phenomenon; The water supply method of the self-provided centralized water supply school is mainly precipitation filtration in the central and southern regions, accounting for 38.46%, 53.21%, and untreated in the northern region(60.61%); The differences of the proportions of having sanitary toilets, detached toilets in schools, having toilets in teaching buildings, and having toilets in dormitory buildings in three regions were of statistical significance(χ2=32.04, 12.73, 20.78, 33.11, P<0.01) The proportion of schools with squat toilets in men’s toilets was greater than that of women’s(χ2=86.53, 44.77, 21.88, P<0.01). The differences of the proportion of schools with faucets available in toilets and within 5 meters around toilets, with sinks in or around the toilets, with sinks equipped with soap in or around the toilets were of statistical significance(χ2=90.02, 10.40, 41.96, P<0.01). Conclusion During 2016 to 2018, the environment sanitation of the three major rural primary and middle schools in Shaanxi Province needs to improve corresponding supporting facilities, and increase publicity to improve teachers and students’ awareness of health and safety.

Objective: To investigate the status and influencing factors of health literacy of middle school students in Yinchuan City, to provide reference for health literacy improvement of middle school students in this region. Methods: Using stratified cluster sampling method, 2 003 middle school students from three districts of Yinchuan were investigated to complete the questionnaire survey.The survey included basic characteristics, health literacy and screen time status. Results: The total score of Chinese Adolescent Interactive Health Literacy Questionnaire was(101.3±17.5). The proportion of high, medium and low level of health literacy were 25.0%, 51.2% and 23.9% respectively;the proportion of long screen time exposure among middle school students was 52.5%. The health literacy level of junior middle school students, middle school students with father or mother education level of high school or above and appropriate screen time were higher than those of the corresponding group（χ 2=49.90，14.59，16.53，46.73，P<0.01）. Logistic regression analysis showed that education group, grade, father s or mother s education level and long screen time exposure were associated with middle school students health literacy level(P<0.05). Conclusion The health literacy level of middle school students in Yinchuan City needs to be further improved and targeted health education should be carried out from school, family and society.

Objective: To understand the status and trend of heavy metal indicators of drinking water in rural schools in different regions of Shaanxi Province, so as to provide scientific basis for safety of drinking water in rural schools. Methods: In 2017-2019, 697 rural school water supply projects in Shaanxi Province were tested for heavy metal indicators in the peripheral water. According to the sanitary standard for drinking water (GB 5749—2006), five heavy metal indicators, including arsenic, cadmium, hexavalent chromium, lead and mercury, were analyzed and evaluated in different years and regions. Results: A total of 2 298 valid water samples were collected and analyzed in 3 years. Except that lead and mercury are all up to standard, the standard rates of other heavy metals such as arsenic, cadmium and hexavalent chromium were 98.83%, 99.91% and 96.95% respectively. Compared with the Northern Shaanxi plateau and Qinba mountain area, the standard rate of water arsenic in Guanzhong Plain was lower (χ2=5.67, 13.59,P<0.01). The standard rate of hexavalent chromium was the highest in Qinba mountain area, followed by Guanzhong Plain, and the lowest in Northern Shaanxi plateau (χ2=20.48, 17.05, 48.32, P<0.01). Two samples of cadmium exceeding standard were from the Northern Shaanxi plateau. Conclusion The heavy metal index of drinking water in rural schools in Shaanxi Province exceeds the standard, which has obvious regional characteristics. We should focus on the harm of arsenic, hexavalent chromium and other heavy metals to the health of students in the Northern Shaanxi plateau and Guanzhong Plain. Cadmium and mercury in drinking water in local areas should be paid continued attention. Safety of drinking water in schools should be ensured from the aspects of water source selection and water treatment technology.

Objective: To investigate and analyze the drinking water quality among rural primary and secondary schools in Guanzhong area in 2018, and to provide a basis for the targeted improvement of water supply facilities. Methods: Develop a questionnaire on the basic situation of centralized water supply in rural schools, according to the Standard Test Method for Drinking Water (GB/T 5750—2006) and the Sanitary Standard for Drinking Water (GB 5749—2006) for the rural school network in Guanzhong area. The peripheral water collection and testing carried out single factor and multifactor statistical analysis on the relationship between water quality influencing factors and water quality pass rate. Results: The total qualified rate of drinking water quality in rural schools in Guanzhong area was 59.1%. Univariate analysis showed that water quality rate was affected by four factors including water source type, engineering type, sanitation permit and disinfection equipment use, and the difference was statistically significant(P<0.05). Unconditional two-class logistic regression analysis showed that disinfection (OR=3.14), engineering type (OR=2.05), and sanitation permit (OR=1.99)(P<0.05) affected the water quality pass rate. Conclusion It is recommended to further strengthen the investment in the renovation of water supply for rural schools in Guanzhong area, and specifically strengthen water supply treatment and standard disinfection.

Objective: To understand the disinfection status and microbial pollution of water supply project in rural schools in Shaanxi Province in 2018, and to provide basis for improving drinking water quality in rural schools. Methods: Data of water quality of water supply project in rural schools of Shaanxi Province in 2018 was collected, and the disinfectant surplus and microbial index compliance rate were analyzed according to "Sanitary Standard for Drinking Water" (GB 5749-2006). Results: The overall compliance rate of microbial indicators of water supply projects in rural schools in Shaanxi Province was 68.09%, and that of groundwater microbial indicators(71.97%) was higher than that of surface water(61.42%)(χ2=15.68, P<0.01); The overall compliance rate of microbial indicators in flood season(71.85%) was higher than that in dry season(64.34%)(χ2=7.44, P<0.01); The rate of reaching the standard of disinfectant residue was 77.27%. The rate of reaching the standard of microbial index of water samples with disinfection measures was higher than that of water samples without disinfection measures (χ2=31.88, P<0.01), The rate of reaching the standard of microbial index of water samples with disinfectant residue(88.89%) was higher than that of water samples with disinfectant residue(44.44%)(χ2=12.28, P<0. 01). Conclusion The main cause of microbial contamination of drinking water in rural schools in Shaanxi Province is inadequate equipment of disinfection equipment in water supply projects or not being used as required. It is suggested that schools, education and health departments should take measures to strengthen supervision and management of water plants to ensure the normal use of disinfection equipment.

Objective:To study the risk factors of complications after bowel resection for acute mesenteric ischemic disease.Methods:Retrospective case-control study was used to analyze the case data of 68 patients diagnosed with acute mesenteric ischemic disease (AMI) with bowel resection at the First Medical Center of the PLA General Hospital from January 2010 to January 2020, including 43 males and 25 females. The patients were divided into complication group ( n=21) and the non-complication group ( n=47) according to whether they had complications after surgery. The risk factors associated with the development of postoperative complications were analyzed by multivariate Logistic stepwise regression method to determine the risk factors with clinical significance. Measurement data with normal distribution were expressed as mean ± standard deviation ( ± s), and t-test was used for comparison between groups. Chi-square test was used for comparison between count data groups. Results:Univariate analysis showed that age >60 years, Marshall score≥2, type of resected bowel, pathology suggestive of irreversible transmural necrosis, length of ICU stay >6 d, length of mechanical ventilation >2 d, American Society of Anesthesiologists (ASA) classification, and preoperative procalcitonin≥2 ng/mL were the risk factors affecting the development of complications after bowel resection for acute mesenteric ischemic disease risk factors ( P<0.05). Multivariate Logistic regression analysis showed that age>60 years ( HR=12.364, 95% CI: 1.135-134.662, P=0.039) and preoperative procalcitonin ≥2 ng/mL ( HR=14.144, 95% CI: 1.280-156.303, P=0.031) were independent risk factors for the development of postoperative complications after AMI parallel bowel resection. Conclusion:The rate of complications after combined bowel resection for AMI is high. When patients are combined with age>60 years and preoperative procalcitonin≥2 ng/mL, preoperative prevention of postoperative complications should be emphasized to improve the prognosis of patients.

Objective To evaluate the value of MRI texture analysis based on gray level co-occurrence matrix to predict cervical lymph node metastasis in patients with tongue carcinoma. Methods A total of 70 patients with tongue carcinoma confirmed by pathology were analyzed retrospectively. The patients were divided into cervical lymph node (LN) metastasis group (unilateral LN+, n=18;bilateral LN+,n=22) and no cervical lymph node metastasis(LN-,n=30). T1W, T2W and contrast-enhanced T1W images of the largest section of tumor were selected. ROI of the lesion was manually drew and GLCM texture parameters (energy, contrast, correlation, inverse difference and entropy) were extracted. The tumor length, thickness and para-lingual distance between tumor and tongue midline were also measured.Differences of all parameters were compared between LN+ group and LN- group, unilateral and bilateral cervical lymph node metastasis group, the parameters with statistically significant difference in predicting the efficiency of cervical lymph node metastasis were analyzed. The diagnostic efficiency of lymph node metastasis was calculated. Results The correlation, inverse difference and entropy based on T2WI showed significant difference (Zcor elation=2.97, tinverse dif erence=5.14, tentropy=2.41; P<0.05), entropy showed the best diagnostic efficiency, the area under the ROC curve (AUC) was 0.90, the cut off value was 7.19, the sensitivity was 80.0％, specificity was 86.7％. Only entropy showed significant difference between unilateral LN+group and bilateral LN+group (P<0.05), the AUC was 0.82, the cut off value was 7.47, the sensitivity was 90.9％, specificity was 78.8％. The index of tumor length, thickness and para-lingual distance between tumor and tongue midline all showed significant difference between LN+group and LN-group (P<0.05), the thickness showed the best diagnostic efficiency, the AUC value was 0.81, the cut off value was 11.19, the sensitivity was 78.0％, specificity was 81.7％. The index of tumor length, thickness and para-lingual distance between tumor and tongue midline showed no significant difference between unilateral LN+ group and bilateral LN+ group (P>0.05). The diagnostic sensitivity of radiologists was 65.0％ (26/40), the specificity was 80.0％ (24/32) on cervical lymph node metastasis. Conclusion Texture analysis based on T2WI can predict cervical lymph node metastasis in patients with tongue carcinoma. Entropy has certain value in predicting bilateral cervical lymph node metastasis.

Objective:To explore the relationship between integrin ɑ3(ITGA3)expression and immune cell infiltration in colorectal cancer(CRC).Methods:Bioinformatic methods were used to analyze ITGA3 mRNA expression in pan-cancer and CRC tissues,as well as its associ-ation with CRC prognosis.The correlation between ITGA3 and tumor-infiltrating immune cells was also investigated.In total,233 cases of CRC diagnosed at Shanxi Provincial Cancer Hospital between January and December 2021 were included,and ITGA3,CD8,CD163,FOXP3,PD-L1,CTLA-4,and PD-1 expression in CRC tissues were determined by immunohistochemistry(IHC)to analyze the relationship between ITGA3 and infiltrating immune cells and immune checkpoints.Results:Bioinformatics analysis showed elevated ITGA3 mRNA levels in CRC.High ITGA3 expression was associated with PFS(P＜0.05).Univariate and multifactorial analyses showed that age and stage were significantly cor-related with prognosis(P＜0.05).In addition,ITGA3 upregulation was closely correlated with multiple immune cell infiltration levels in CRC.Furthermore,IHC results showed that ITGA3 expression in CRC tissues was significantly higher than that in adjacent normal tissues(P＜0.05).ITGA3 expression was associated with lymph node metastasis(P＜0.05)and correlated with the expression of immune markers,such as CD8+T-cells,PD-L1,and CTLA-4(P＜0.05).Conclusions:ITGA3 is highly expressed in CRC,which is closely related to immune cell infiltration and may regulate the tumor immune microenvironment,which provides a new idea for clinical treatment and a potential new independent predictive marker.

Background:The TNM staging system is far from perfect in predicting the survival of individual cancer patients because only the gross anatomy is considered. The survival rates of the patients who have the same TNM stage disease vary across a wide spectrum. This study aimed to develop a nomogram that incorporates other clinicopatho-logic factors for predicting the overall survival (OS) of non-metastatic nasopharyngeal carcinoma (NPC) patients after curative treatments. Methods:We retrospectively collected the clinical data of 1520 NPC patients who were diagnosed histologically between November 2000 and September 2003. The clinical data of a separate cohort of 464 patients who received intensity-modulated radiation therapy (IMRT) between 2001 and 2010 were also retrieved to examine the extensibil-ity of the model. Cox regression analysis was used to identify the prognostic factors for building the nomogram. The predictive accuracy and discriminative ability were measured using the concordance index (c-index). Results:We identiifed and incorporated 12 independent clinical factors into the nomogram. The calibration curves showed that the prediction of OS was in good agreement with the actual observation in the internal validation set and IMRT cohort. The c-index of the nomogram was statistically higher than that of the 7th edition TNM staging sys-tem for predicting the survival in both the primary cohort (0.69 vs. 0.62) and the IMRT cohort (0.67 vs. 0.63). Conclusion:We developed and validated a novel nomogram that outperformed the TNM staging system in predict-ing the OS of non-metastatic NPC patients who underwent curative therapy.