Objective To compare imaging quality and radiation dose of different anode filter combination for full-field digital mammography.MethodsThe image of FLUKE NA 18-220 phantom were taken at full-field digital mammography (FFDM),system with Mo/Mo,Mo/Rh,Rh/Rh anode/filter combination by automatic exposure control,record the exposure factors and doses.The images on monitor with the best window width and window level were read by 4 independent radiologists,the images of specks groups,nylon fibers and masses was assessed by the 4 experienced readers at the criterion of American College of Radiology 1999 mammography quality control manual.Statistical analysis was performed using analysis of variance.ResultsThe nylon fibers scores of Mo/Mo,Mo/Rh and Rh/Rh were 5.50 ± 2.12,4.50 ± 1.85 and 4.38 ± 1.38 ; the specks groups scores of Mo/Mo,Mo/Rh and Rh/Rh were 5.38 ± 1.98,4.25 ± 1.56 and 4.38 ± 1.38;the masses scores of Mo/Mo,Mo/Rh and Rh/Rh were 5.38 ± 1.98,4.38 ±1.68 and 4.25 ± 1.56,the detection of specks groups,nylon fibers was not statistically significant ( F =4.56 and 4.32,P ＞ 0.05 ),but the detection of masses was statistically significant ( F =36.65,P ＜ 0.05).The radiation doses were different,the entrance surface dose (ESD) and average glandular dose (AGD) of Rh/Rh were (5.11 ± 1.89) and ( 1.08 ± 0.13 ) mGy,the ESD and AGD of Mo/Mo were (6.66 ± 2.33 )and ( 1.29 ± 0.38 ) mGy,the ESD and AGD of Mo/Rh anode/filter combination were (5.67 ± 2.02) and ( 1.29 ± 0.38) mGy.ConclusionsThe radiation dose of Rh/Rh and Mo/Rh anode/filter combination of FFDM were lower,and the imaging was clear,so Rh/Rh and Mo/Rh anode/filter combination of FFDM prefer to mostly patients,especially when the thinkness is large,Rh/Rh anode/filter combination is preferred,because the kV values was higher,the penetration of X-ray was stronger.The Mo/Mo anode/filter combination was used when the needs of high-resolution,because the detection of masses of it was better.

AIM: To study the interrelation between the structure and the function of artificial ribozyme M_1GS. METHODS: Ribozyme M_1GS-T_7, which targeted the mRNA segment of HCMV UL54 gene, was constructed. The secondary structure of M_1GS was simulated under different temperatures (20 ℃, 37 ℃ or 55 ℃, at which the secondary structure of M_1GS was relatively stable) and the interrelation between the secondary structure and the cleavage activity of M_1GS was analyzed under different temperature in vitro. To investigate the interrelation between the structure and the function of ribozyme M_1GS further, mM_1GS-T_7 was designed, in which some mutation sites was added, according to the result of temperature change experiment and the simulated secondary structure, showing that were the same structures at 37 ℃ as that of M_1GS-T_7 at 55 ℃. RESULTS: In temperature change experiment, the cleavage activity of M_1GS-T_7 was highest at 55 ℃. The result of mutant experiment showed that the mutant type was more active than M_1GS-T_7 at 37 ℃. CONCLUSION: The cleavage activity of M_1GS, which has some certain secondary structure, is higher than others. There is some interrelation between the structure and the function of M_1GS.

Objective To compare imaging quality and radiation dose on full-field digital mammography (FFDM) system and dual-sided reading CR mammography (DSCRM) system.Methods The TRM of ALVIM statistics phantom was exposed by FFDM system and (DSCRM) with the same radiation dose.The exposure parameters and the entrance surface dose (ESD) were recorded.Then,the phantom was exposed by DSCRM system with different mAs and same kV,and the ESD was recorded.The images obtained above were read by three radiologists on the monitor of diagnosis work station with the same window width and window level.The evaluation of the images were given using a five-level confidence scale.ROC curves were drawn and probability Pdet were calculated.Results The ROC analysis of microcalcifications and masses showed A(z) values of 0.730-0.925 and 0.670-0.945 for FFDM,and 0.632-0.815 and 0.575-0.785 for DSCRM when the radiation dose is 1.36 mGy.The radiation dose with DR system could be reduced compared with dual-sided reading CR system at the same probabilities Pdet,the ESD reduced from 1.63 mGy to 1.36 mGy by 19.8％,the AGD reduced from 0.65 mGy to 0.56 mGy by 16.0％.Conclusions The observable details with FFDM system were proved to be superior to DSCRM system at the same radiation dose.With the similar image quality,the radiation dose of FFDM system was less than the DSCRM system.

Objective To examine the prevalence of chikungunya virus in brain tissue samples from rat?like animals in Xiamen, Shenzhen and Guangzhou, and to explore whether the rat?like animals are potential sources of human chikungunya fever infections and the host of the virus. Methods Rat?like animals were trapped in residential areas, city parks, hospitals, markets and schools in Xiamen, Shenzhen and Guangzhou (Yuexiu and Baiyun districts) between January 2013 and June 2016. Brain tissue samples of the trapped animals were collected under sterile. Chikungunya virus was detected by using reverse transcription polymerase chain reaction (RT?PCR). Results Totally 1092 rat?like animals were trapped, which belonged to 7 species, 3 genera, 2 families, 2 orders. Rattus norvegicus was the dominant species in the indoor environment, Rattus losea was dominant in wild environment, and 1092 brain tissue samples were collected. No detectable chikungunya virus was found in the brain tissue samples by RT?PCR. Conclusion There is a low possibility that rat?like animals act infectious sources of human chikungunya fever infections and the host of the virus.

We detected Zika virus (ZIKV) in a febrile case returning from Suriname and entry China from Guangzhou Baiyun International Airport Port.Serum and saliva samples were collected from a suspected case returning from Suriname.We detected ZIKV RNA using real-time fluorescence RT-PCR methods by both in-house reagent and commercial detection kits.RT-PCR detection was carried out with saliva sample and sequence analysis was performed.Phylogenetic tree was constructed to analyze the source of imported cases.Real-time fluorescent RT-PCR result showed that saliva was detected ZIKV RNA positive while for serum was weakly positive.A specific 1 500 bp fragment in size was amplified with saliva sample by RT-PCR.Sequence analysis showed 99％ homologous to the corresponding sequence of Brazil ZIKV (GenBank No.KX197250).Phylogenetic tree indicated it was located on African lineage.According to the epidemiological investigation results,clinical manifestations and nucleic acid detection of case,the suspected case was confirmed to infect Zika virus,being the first case from Suriname into Guangdong Province.

OBJECTIVETo study the metabolic changes of pancreatic extracts from insulin-resistant rats induced by fructose feeding using nuclear magnetic resonance ¹H spectroscopy (¹H NMR).

METHODSSixteen Wistar rats were divided equally into control group and model group and given water and 10% fructose water for 8 weeks, respectively. The pancreatic tissues were then obtained for H NMR spectra analysis and principal component analysis (PCA).

RESULTSCompared with the control rats, the rats in the model group showed significantly increased creatine, betaine/TMAO, taurine, glycine and myo-inositol and decreased levels of lipids, lactate, glutamate, choline and GPC/PC.

CONCLUSION¹H NMR and pattern recognition can define the metabolic characteristics of the pancreatic tissue extracts from insulin-resistant rats and provide reliable metabolic evidence for studying the mechanisms of insulin resistance at the molecular level.

Animals ; Fructose ; Insulin Resistance ; Metabolomics ; Pancreatic Extracts ; chemistry ; Principal Component Analysis ; Proton Magnetic Resonance Spectroscopy ; Rats ; Rats, Wistar

Objective:To develop a single-tube one-step multiplex nested real-time reverse transcription polymerase chain reaction (RT-PCR) assay for the simultaneous detection of 2019-nCoV, influenza A virus, influenza B virus and internal-control with human-derived gene.Methods:This study included 30 positive specimens for 2019-nCoV nucleic acid detection and 336 screening specimens collected from the arrivals at Guangzhou Baiyun Airport between February 2020 and February 2022. Sixty-four positive specimens of other respiratory pathogens were also collected from the arrivals at Guangzhou Baiyun Airport during the three-year period before the occurrence of COVID19 outbreak in 2020, and 7 positive viral strains of respiratory pathogens were provided by collaborative laboratories. In order to establish a set of multiplex nested real-time RT-PCR assay, a group of primers and probe combinations for a multiplex nested real-time RT-PCR was designed and screened according to a selection of nucleotide conserved regions of the ORF and N genes of 2019-nCoV and the M gene of influenza A and B viruses, while nested amplification primers and probe for the internal-control with human-derived gene were introduced. Then the prepared pseudovirus-positive quality control and sample discs were applied to evaluate the sensitivity and specificity. Clinical specimens were performed to validate the applicability of the method.Results:The results show that the established one-step multiplex nested real-time RT-PCR assay can specifically detect 2019-nCoV and influenza A and B viruses, with the limit-of-detection of about 125 copies/ml for 2019-nCoV and about 250 copies/ml for influenza A and B viruses. Totally 101 positive samples of various respiratory pathogens were detected, showing that the detection sensitivities of 2019-nCoV and influenza A and B viruses were 96.67%, 92.86% and 96.15%, respectively, with the specificity of 100%. No false-positive detection was found in the applied detection of more than 300 clinical samples.Conclusions:A one-step multiplex nested real-time RT-PCR assay for 2019-nCoV, influenza A and B viruses and human-derived gene internal-control was developed. The assay has good sensitivity and specificity and can be used for rapid screening of 2019-nCoV and influenza A and B viruses in high-volume samples.

OBJECTIVE：To stu dy the improvem ent effect and mechanism of Guizhi fuling pill （GZFLP） on rats with phlegm-dampness type polycystic ovary syndrome （PCOS）.METHODS：Totally fifty female SD rats with regular estrous cycle were randomly divided into blank control group （n＝10） and model group （n＝40）. The model group received letrozole intragastrically [1 mg/（kg·d），for 21 d ] to induce phlegm-damp PCOS rat model. Forty model rats were randomly divided into model group ，metformin group [positive control ，0.135 g/（kg·d）] and GZFLP low-dose ，high-dose groups [4.49，17.96 g/（kg· d）]，with 10 rats in each group. Each medicine group was given intragastric administration ，once a day ，for 30 consecutive days. Blank control and model group were given intragastric administration of equal volume normal saline.After last medication ，oral glucose tolerance test （OGTT）was used to detect the level of blood glucose in rats at 0，30，60 and 120 min. ELISA assay was used to detect the levels of follicle-stimulating hormone （FSH），luteinizing hormone （LH），estradiol（E2）and testosterone （T）； body weight ，the weight of uterus ，bilateral ovaries and paragonadal fat were weighed. HE staining was used to observe morphological changes of ovarian tissue sections. RT-PCR method and Western blotting assay were used to detect mRNA and protein expression of CYP 19a1 in ovary and Glut 4 in uterine. RESULTS ：Compared with blank control group ，the levels of blood glucose 30，60，120 min after intragastric administration of glucose solution as well as serum levels of LH ，E2 and T were increased significantly in model group （P＜0.05）；the body weight ，the weight of uterus ，bilateral ovaries and paragonadal fat were increased significantly （P＜0.05）；the volume of thecal cells increased significantly and showed spherical shape ；the mRNA and protein expression of CYP 19a1 in ovarian tissue and Glut 4 in uterine tissue were decreased significantly （P＜0.05 or P＜0.01）. Compared with model group ，above indexes of administration groups were improved significantly （P＜0.05 or P＜0.01）；the thickness of theca cell layer and the volume of theca cells in GZFLP low-dose and high-dose groups were also improved. CONCLUSIONS：GZFLP can up-regulate the expression of CYP19a1 in ovary and Glut4 in uterus ，so as to improve the abnormal glucose metabolism in phlegm-dampness type PCOS model rats ，reduce insulin resistance ，lower serum estrogen levels ，and reduce the degree of polycystic changes in ovary ，thereby playing a role in the treatment of PCOS.

Objective:To learn about the iodine nutritional status of children aged 8 to 10 years in Xiamen City after the reform of salt industry system, and to provide scientific basis for reasonable prevention and control of iodine deficiency disorders.Methods:From 2017 to 2019, 6 districts were selected each year in Xiamen City 5 sampling districts were divided according to the oriation of east, west, south, north and center in each district. One town (street, hereinafter refered as to town) was selected from each sampling district. One primary school was selected from each town. For each primary school, at least 40 non-boarding children aged 8 to 10 years (age balanced, half male and half female) were selected. Edible salt samples in the households and random urine samples of children aged 8 to 10 years were collected, and salt iodine and urinary iodine contents were measured, while thyroid volume was examined by B-ultrasound.Results:From 2017 to 2019, the coverage rate of iodized salt in Xiamen City was 97.34% (1 206/1 239), 96.89% (1 214/1 253), and 93.33% (1 175/1 259), respectively; the consumption rate of qualified iodized salt was 96.13% (1 191/1 239), 95.61% (1 198/1 253), and 91.58% (1 153/1 259), respectively; the median urinary iodine was 182.90, 182.81, 164.00 μg/L, respectively. The prevalence of goiter of boys and girls was 1.01% (19/1 889) and 2.26% (42/1 862), respectively.Conclusions:After the reform of salt industry system, the iodine nutritional status of children aged 8 to 10 years is generally at an appropriate level in Xiamen City. However, the consumption rate of qualified iodized salt is reduced, which increases the risk of iodine deficiency for residents. Therefore, we should strengthen the propaganda of scientific iodine supplement, maintain a high consumption rate of qualified iodized salt, and prevent the harm of iodine deficiency.

A 11-year old female patient with severe thalassemia, receipt a lentivirus-based cell and gene therapy (CGT) therapy in Shenzhen Children′s Hosptial on July 27th, 2021. At the two follow-up visits after discharge, patient were continuously tested positive for HIV screening through HIV Ag/Ab Combo assay (chemiluminescence Immunoassay), and the viral load results of HIV-1 nucleic acid testing (NAT) were both>5 000 copies/ml. The patient can be diagnosed with HIV infection according to the National Guideline for Detection of HIV/AIDS(2020 Revised Edition). The thorough investigation findings and supplementary experiment results indicated that the false-positive HIV-1 NAT results was caused by cross-reactivity between the target sites detected by conventional HIV-1 NAT reagents and the lentiviral vectors fragments integrated into the genome of patient′s hematopoietic stem/progenitor cells. In conclusion, it is important for laboratories to select appropriate HIV-1 NAT testing platforms which won′t cause cross-reactivity for the testing of samples from patients who have been treated with HIV-derived vectors. It is also recommended to design and develop NAT testing platforms with multiple target regions labeled by different fluorescents for HIV NAT supplementation experiment to reduce the risk of false-positive diagnoses of HIV infection.