With the extensive application of nuclear technology in industry, agriculture, and medicine, the safety issues associated with neutron radiation have become increasingly prominent. Due to their high penetrability and strong ionization effect, neutrons can cause serious health risks by directly damaging DNA or inducing secondary γ radiation. Therefore, the neutron radiation protection has become a core challenge in radiation protection, especially the research and development of neutron shielding materials. To ensure the safe development of nuclear technology, neutron shielding materials are indispensable and constitute a fundamental core technology for radiation protection. This paper reviews the theory of neutron radiation protection and the research progress of neutron shielding materials, with a focus on the current application status and existing problems of neutron shielding materials. This article also discusses the future development trends. This review aims to provide theoretical support and technical references for the safe application and development of nuclear technology.

ObjectiveTo explore the therapeutic effect of Huangliansan on atopic dermatitis （AD） model mice induced by 2， 4-dinitrochlorobenzene （DNCB）. MethodA total of 42 male BALB/c mice were randomly divided into normal group， model group， hydrocortisone group， low， medium， and high-dose groups （0.3， 0.6， 1.2 g·kg^-1） of Huangliansan oil， and water extract group （0.6 g·kg^-1） of Huangliansan. In addition to the normal group， DNCB was applied on the back of mice in other groups to establish the AD model. On the 15^th day after DNCB stimulation， each group was given the corresponding drug or solvent， and the changes in skin lesions， dermatitis score， and frequency of scratching were observed and recorded. Hematoxylin-eosin （HE） staining was used to observe the histopathological changes in the skin and spleen. Real-time fluorescent quantitative polymerase chain reaction （Real-time PCR） was used to detect mRNA levels of filaggrin （FLG）， lorophane （LOR）， and involucrin （IVL） in skin， as well as immunoglobulin E （lgE）， interleukin-4 （IL-4）， interleukin-6 （IL-6）， interleukin-1β （IL-1β）， tumor necrosis factor-α （TNF-α）， and interferon-γ （IFN-γ） in spleen. ResultCompared with the normal group， the model group showed symptoms of skin swelling and scab， and the score of dermatitis， the frequency of scratching， and the spleen index were increased （P<0.05）. The expression levels of FLG， LOR， and IVL in skin tissue were significantly decreased （P<0.01）， and the mRNA expressions of IgE， IL-4， IL-6， IL-1β， and TNF-α in the spleen were significantly increased， while the expression level of IFN-γ was significantly decreased （P<0.01）. Compared with the model group， the symptoms of skin erythema， scaly， and scab of mice in each drug group were alleviated to varying degrees， and the score of dermatitis， the frequency of scratching， and the spleen index were decreased （P<0.05， P<0.01）. In addition， the expression levels of FLG， LOR， and IVL in the skin of mice in the drug group were increased （P<0.05， P<0.01）， and the mRNA expression of IgE， IL-4， IL-6， IL-1β， and TNF-α in spleen were decreased. IFN-γ was increased （P<0.05， P<0.01）， and the lesions of the skin and spleen were improved to varying degrees. The medium-dose group of Huangliansan oil and hydrocortisone group had the most obvious manifestations （P<0.05， P<0.01）. The indexes in the medium-dose group of Huangliansan oil were better than those in the water extract group of Huangliansan. ConclusionHuangliansan may improve the expression level of skin barrier protein， inhibit the expression of helper T cell 2 （Th2）-related inflammatory factors， increase the expression of helper T cell 1 （Th1） inflammatory factors， restore the skin barrier function and Th1/Th2 balance in the spleen， regulate the inflammatory response in the spleen of AD mice， and thus relieve AD. Huangliansan oil is more effective than water extract.

Objective To establish an immortalized tree shrew corneal stromal cells(CSCs)line and to study its response to virus infection.Methods Primary tree shrew CSCs were isolated and cultured by the tissue block adhesion method.CSCs were then transfected with a lentivirus carrying the SV40T gene and monoclonal cells were selected for passage culture.The characteristics of the CSCs were investigated by morphological observation and compared with 40 generations until the 50 generations or more,immunofluorescence identification of vimentin and SV40T genes,karyotype examination,and cell proliferation curve.The CSCs were infected with herpes simplex virus-1(HSV-1)(McKrae strain),Zika virus(ZIKV,GZ01 strain),Dengue virus typeⅡ,and H1N1(PR8).Results The immortalized tree shrew CSCs after＞50 passages appeared spindle-shaped with good cell morphology and structure compared with 40 generations.Positive immunofluorescence expression of vimentin and SV40T genes.The cell growth curve showed that the cells were in logarithmic-phase growth on days 4～5 and grew vigorously.The number of chromosomes in the primary cells was stable at 62,while immortalized CSCs had 64 chromosomes at P21 and P56.The virus titer results showed that the immortalized tree shrew CSCs were sensitive to HSV-1(McKrae strain),ZIKV(GZ01 strain),Dengue virus typeⅡ,and H1N1(PR8),with virus titers of 1.32×105,5.62×106,2.69×107,and 7.76×104 CCID50/mL,respectively.Conclusions The immortalized tree shrew CSCs were established successfully,suggesting that this cell line is suitable for studies of the mechanisms of HSV,ZIKV,Dengue virus,and influenza A virus infection in relation to corneal diseases and antiviral drugs.

Objective:To investigate the level of serum vascular endothelial growth factor (VEGF) and its correlation with clinical symptoms in patients with first-episode drug-naive schizophrenia patients of different genders.Methods:From January 2016 to October 2019, a total of 81 first-episode drug-naive schizophrenia patients(patient group, 41 male, 40 female) and 64 healthy controls (control group, 40 male, 24 female) were included in this study.The serum level of VEGF was detected with flow cytometric bear array (CBA). Positive and negative symptom scale (PANSS) was used to evaluate the relevant clinical symptoms of patients.SPSS 22.0 software was used for statistical analysis.Independent sample t-test and nonparametric test were used for comparison between groups.The relationship between VEGF and clinical variables was analyzed by Pearson correlation analysis and Spearman correlation analysis. Results:The level of serum VEGF in the patient group was significantly lower than that in the control group(148.08(75.89, 208.61)pg/mL, 179.94(99.14, 318.41)pg/mL, Z=-2.20, P=0.028). The total PANSS score((82.71±17.30), (73.45±16.36), t=2.473, P=0.016)and cognitive score((7.88±3.36), (6.23±2.81), t=2.402, P=0.019) in male patients were higher than those in female patients.There was a negative correlation between VEGF level and PANSS negative symptom score in the patient group( r=-0.228, P=0.041), as well as significant negtive correlation between VEGF level and cognitive score in male patients( r=-0.425, P=0.007). Conclusion:The level of serum VEGF is reduced in first-episode patients with schizophrenia, which influences their negative symptom. Moreover, the decline in serum VEGF level is implicated in cognitive impairments in male patients with first-episode schizophrenia.

Congenital cardiovascular disease is a kind of congenital disease caused by the interaction of multiple factors such as heredity, environment and pregnancy infection, but its exact etiology is still unclear.With the deepening of research, more and more evidences show that genetic factors play a significant role in its pathogenesis.Many genes are involved in the development of heart embryos, and the mutation of these genes often leads to congenital cardiovascular diseases.Homology modeling is a technique to predict the structural and functional changes of proteins caused by gene mutation through computer algorithm, and its application in the pathogenesis of congenital diseases has become a future trend.The purpose of this paper is to review homology modeling and its application in pathogenesis of congenital cardiovascular diseases briefly.

【Objective】 To evaluate the association between prophylactic plasma transfusion and postoperative bleeding rate in critically ill patients undergoing different invasive procedures. 【Methods】 The information of ICU patients who received different invasive procedures from January 2019 to December 2019 in 6 tertiary hospitals in China were retrospectively investigated. The inclusion criteria of patients were as follows: age ≥ 18 years; received invasive procedures; INR ≥ 1.5 within 72 hours before surgery. Exclusion criteria were patients with incomplete case records. The patients finally included in the study were divided into prophylactic plasma transfusion group and non-prophylactic plasma transfusion group according to their plasma transfusion status. The outcome variable was the incidence of invasive procedure-related bleeding within 48 hours after different invasive procedures. 【Results】 A total of 407 patients underwent invasive procedures, and 362 patients were finally included in this study after excluding 45 patients with incomplete case records. The proportions of prophylactic plasma transfusion in different types of invasive procedures were central venous catheterization (46/146, 31.5%), thoracentesis (13/37, 35.1%), bronchoscopy (8/31, 25.8%), tracheal intubation (9/38, 23.7%), arterial catheterization (9/50, 18.0%) and others (13/60, 21.7%). The bleeding rates showed that different invasive procedures presented no statistical difference between the groups received plasma transfusion or not. In the prophylactic plasma transfusion group, the bleeding rate of arterial catheterization (4/9, 44.4%) was the highest, but all were potential bleeding, followed by tracheal intubation (4/10, 40.0%) and central venous intubation (16/46, 34.8%), with a higher rate of significant bleeding. 【Conclusion】 Prophylactic infusion of plasma did not reduce the bleeding rate after different invasive procedures, but prospective studies are needed to further confirm the conclusion; this study also provides a certain data basis for later prospective studies.

High levels (> 100 ug/L) of arsenic are known to cause lung cancer; however, whether low (≤ 10 ug/L) and medium (10 to 100 ug/L) doses of arsenic will cause lung cancer or other lung diseases, and whether arsenic has dose-dependent or threshold effects, remains unknown. Summarizing the results of previous studies, we infer that low- and medium-concentration arsenic cause lung diseases in a dose-dependent manner. Arsenic trioxide (ATO) is recognized as a chemotherapeutic drug for acute promyelocytic leukemia (APL), also having a significant effect on lung cancer. The anti-lung cancer mechanisms of ATO include inhibition of proliferation, promotion of apoptosis, anti-angiogenesis, and inhibition of tumor metastasis. In this review, we summarized the role of arsenic in lung disease from both pathogenic and therapeutic perspectives. Understanding the paradoxical effects of arsenic in the lungs may provide some ideas for further research on the occurrence and treatment of lung diseases.
Animals ; Arsenic/toxicity* ; Dose-Response Relationship, Drug ; Humans ; Lung/pathology* ; Lung Neoplasms/drug therapy* ; Mice

Objective:To investigate the changes and to establish a reference interval of bile acid profile of healthy pregnant women in the second and third trimesters of pregnancy in our hospital.Methods:A total of 298 healthy singleton pregnant women who underwent prenatal examination in the Department of Obstetrics of Zhejiang Provincial People′s Hospital from July 2019 to August 2020 were enrolled in this study. The overnight fasting serum samples were collected from all subjects during their second and third trimesters of pregnancy. The concentrations of 15 bile acids(cholic acid, chenodeoxycholic acid, deoxycholic acid, ursodeoxycholic acid, lithocholic acid and their glycine-and taurine-conjugated types)were analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS). The characteristics of changes were analyzed and the reference intervals were determined for the second and third trimesters. The concentrations of 15 bile acids and total bile acids were skewed-distributed, and 99 percentiles (P 99) were used to represent the unilateral upper limit of the reference interval. Results:There was significant difference in the serum levels of glycine cholic acid (GCA), taurocholic acid (TCA), glycine ursodeoxycholic acid (GUDCA) and lithocholic acid (LCA) between the second and third trimesters healthy pregnant females ( P<0.05). For other 11 bile acids, there was no significant difference. The levels of total bile acids, primary or secondary bile acids, free or conjugated bile acids (glycine-bound and taurine-bound bile acids) were stable with gestation. Conclusion:Primary, secondary or free, and conjugated bile acids in healthy pregnant women remained stable at T 2 and T 3, with significant differences in only a few subtypes of bile acids. While the correlation between glycine-bound and taurine-bound bile acids showed a weakening trend at T 3 ( P<0.05). It is necessary to establish reference intervals of bile acids for healthy pregnant women in this area. This study provided data support for future research on related diseases during pregnancy.

OBJECTIVE：To establish the method for content determination of 17 kinds of amino acids in Sargassum and its adulterants，and to carry out cluster analysis ，so as to provide reference for quality control of Sargassum. METHODS ：Totally of 18 batches of sample （S1-S6 as certified product ，S7-S18 as adulterants ）were collected. After acid hydrolysis ，amino acids contents were detected by using automatic amino acid analyzer. The separation was performed on LCAK 06/Na sulfonic acid cation exchange resin column with mobile phase consisted of buffer-regeneration system （gradient elution ）at the flow rate of 0.45 mL/min （elution pump ）and 0.25 mL/min（derivative pump ）. The detection wavelengths were set at 440 nm（proline）and 570 nm（other amino acids ），and the sample size volume was 50 μL. PASW Statistics 18.0 software was used ，and cluster analysis was conducted by using group connection method of cluster analysis with “square Euclidean distance ”as the measurement standard. RESULTS ：17 kinds of amino acids were well separated without interference from blank sample. The linear relationship between mass concentration and peak area was good （all r were over 0.998），and the upper and lower limits of the linear range were 48.06 μg/L （cystine）and 1.501 μg/L（glycine），respectively；RSDs of precision ，reproducibility and stability tests were lower than 2％. The average recoveries were between 90.60％-101.56％（RSDs were 0.88％-2.15％，n＝6）. 17 kinds of amino acids were detected in Sargassum and its adulterants ，among which the contents of glutamic acid ，aspartic acid ，leucine，alanine，glycine and valine were relatively high . Results of cluster analysis showed that 18 batches of sample were clustered into 4 categories，i.e. S 1-S6 into one category；S7-S9 into one category ；S10-S12，S16-S18 into one category ；S13-S15 into one category ；which was consistent with the identification result of Sargassum and its adulterants . CONCLUSIONS ：The method is simple ， rapid， accurate and reproducible，and can be used for the quantitative analysis and identification of amino acids in Sargassum and adulterants.

Objective:To make the early clinical antibiotic regimen by finding out the infection of corynebacterium in the pus of patients with granulomatous mastitis in the early stage.Methods:A total of 42 patients who were diagnosed and treated in the Breast Center of Guangdong Maternal and Child Health Hospital from Jun. 2016 to Mar. 2017 with complete follow-up data were retrospectively analyzed. PCR method was used to detect corynebacterium in the patients’ pus. Patients in the positive group were treated with antibiotics alone, antibiotics + hormones and hormones alone, while patients in the negative group were treated with antibiotics + hormones and hormones alone. The postoperative recurrence rate and cure rate of different groups of patients were observed.Results:The antibiotic regimen for granulomatous mastitis in patients with corynebacterium infection included a combination of short-acting levofloxacin and azithromycin and long-acting anti-mycobacterium drugs. Among the 42 patients in the subgroup, 21 patients were confirmed positive for corynebacterium by PCR detection of pus, and the postoperative recurrence rate was 23.5%. There was a statistically significant difference between the antibiotic group, the antibiotic + hormone group and the hormone group in treatment of granulomatous mastitis infected with corynebacterium ( χ2=5.494, P=0.036) . PCR detection shouwed corynebacterium negative in 21 cases, and postoperative recurrence rate of 16.7%. No statistically significant difference in efficacy was found between antibiotic + hormone group and hormone only group for GM patients without bacterial infection ( χ2=1.129, P=0.719) . Conclusion:Early detection of corynebacterium infection in GM patients is significant for clinical guidance of the application of lipophilic antibiotics.