Objective To explore the optimum voltage for digital chest radiography in adult. Methods PMMAs of Different thickness (7.2, 9.0, 10. 8 and 12. 6 cm) were used to simulate chest of different depth ( 17. 5, 22. 5, 27.0 and 32. 5 cm). The combinants of contrast-detail Cdrad 2.0 phantom and above PMMAs were exposed with automatic exposure control (AEC) and different tube voltages. The images of these combinants were obtained and the entrance surface dose (ESD) was recorded. The imaging quality factor (IQF) was calculated and the curves were drawn between the ESD,IQF and kV. The PMMAs of different thickness, on which a contrast object ( PMAA of 5 cm diameter and 1.8 cm thickness ) was placed, were exposed with the same condition used for above test. Their images were obtained and SNRs were calculated. Results The ESD, SNR and IQFinv of different chest depth decreased with increase of kV.When tube voltages of 70, 100 and 140 kV were used, for 17. 5 cm chest depth, the ESD was 0. 22, 0. 09 and 0. 06 mGy, the IQF was 43.3, 58. 8 and 72. 0, the SNR was 7.5, 6. 2 and 5.0; for 22. 5 cm chest depth, the ESD was 0.37, 0.12 and 0.06 mGy, the IQF was 56. 0, 61.4 and 65.3, the SNR was 6. 4, 5.2 and 3. 8; for 27. 0 cm chest depth, the ESD was 0. 52, 0. 20 and 0. 09 mGy, the IQF was 54. 2, 64. 3 and 91. 0, the SNR was 6. 0, 4. 8 and 3. 5; for 31.5 cm chest depth, the ESD was 0.53, 0.24 and 0. 10 mGy,the IQF was 53.2, 66. 8 and 95.3, the SNR was 5. 7, 4. 5 and 3. 0. Conclusion To balance ESD, SNR and IQF, proper tube voltage should be chosen for chest radiography according to thickness and constitution of patients.

Objective To compare imaging quality and radiation dose on DR and dual-sided reading of CR system.Methods The TRG of ALVIM statistics phantom was exposed by DR and dual-sided reading of CR with the same radiation dose,then the exposure factor and the entrance surface dose (ESD) were recorded.After that,the phantom was exposed by dual-sided reading of CR with various mAs ( 3.2,4.0,4.3,4.8 and 5.2 mAs) and the same kV,and the ESD was recorded,too.The acquired images were read by three radiologists on the monitor of diagnosis work station with the same window width and window level,then the total points of the images were given with the method of a five-level confidence scale.ROC curves were drawn and probability Pdet was calculated.Then the data was analyzed statistically by analysis of variance (ANOVA).Results The ROC analysis of bone substitute with diameter from 0.5 to 1.0 mm and muscle substitute with diameter from 0.9 to 2.0 mm showed A (z) values of 0.742 to 0.923 and 0.635 to 0.900 for DR system when the radiation dose was 137.5 μGy.The ROC analysis of bone substitute and muscle substitute showed A(z) values of 0.526 to 0.586 and 0.473 to 0.560 for dual-sided reading of CR at the same radiation dose.The probability Pdet discrepancy of bone substitute in two systems was from 0.216 to 0.337,with the highest of 0.337 in the diameter of 1.0 mm.The probability Pdet discrepancy by muscle substitute in two systems was from 0.075 to 0.342,with the highest of 0.342 in the diameter of 2.0 mm.There was significant statistical difference between the two groups ( F =35.30,P ＜ 0.01 ).When the exposure factor of dual-sided reading of CR system was 75 kV,4.8 mAs,the ESD was 180.4 μ Gy,the ROC analysis in the bone substitute with diameter from 0.5 to 1.0 mm and muscle substitute with diameter from 0.9 to 2.0 mm showed A(z) values was the same.The probability Pdet discrepancy of bone substitute in two systems was from - 0.003 to 0.009.The probability Pdet discrepancy of muscle substitute in two systems was from -0.005 to 0.008,and there was no statistical difference between the two groups ( F =5.23,P ＞0.05).When the probability Pdet of two systems was the same,the ESD was 180.4 μGy by dual-sided reading of CR system,and the ESD was 137.5 μGy by DR system.Conclusion Detection with DR system was proved to be superior to dual-sided reading of CR system at the same radiation dose.When the image quality was similar,the radiation dose of DR system was less than the dual-sided reading of CR system.

Objective To research the efficacy of using low dose dexmedetomidine in short time to prevent restless after laparoscopic surgery. Methods Forty patients ASA grade ⅠorII,age 20~70 yeas old,scheduled for selective laparo-scopic cholecystectomy or ectopic pregnancy or oophorocystectomy etc,operation time about 30min,were randomly as-signed to low groupsgroup D and N. Group DIntravenous dexmedetomidine(0.5~0.8)μg/(kg·h) when we inducing,for 10~15 min,no more than 50 μg; Group Nno dexmedetomidine. Observed extubation tiwe after surgery,riker sedation and restless score(SAS),restless incidence rate. Results There was no obvious difference in the time of extract the tra-cheal tube (P>0.05). The SAS in group D was significantly lower than group N (P<0.05),incidence of restlessness of group D was significantly lower than N. Conclusion Intravenous low dose dexmedetomidine while inducing for short time can effectively prevent restlessness after Laparoscopic Surgery.

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.

Objective:To study the effect of magnetic nursing concept on improving nurses' nursing ability of extracorporeal membrane oxygenation (ECMO).Methods:In the study, 33 nurses of emergency intensive care unit of The First Affiliated Hospital of Nanjing Medical University from January 2019 to December 2020 were selected as the research objects. From January 2019 to December 2019, the Department carried out routine nursing management, and from January 2020 to December 2020, the Department implemented the management mode of magnetic nursing concept. The mastery of nursing knowledge of ECMO was analyzed by using scale, and the critical thinking ability and self-study ability of the nurses were compared before and after intervention. SPSS 22.0 was used to perform t test on the data. Results:After the intervention, nurses' mastery of respiratory system nursing, circulatory system nursing, fluid balance nursing, skin nursing, digestive system nursing, bleeding, anticoagulant problem nursing, hospital infection prevention and control, and pipeline nursing related knowledge of ECMO patients was significantly better than that before the intervention ( P<0.05). After the intervention, nurses' truth-seeking, open thinking, systematic ability, analytic ability, thinking self-confidence, thirst for knowledge, cognitive maturity and total scale scores were significantly higher than those before the intervention ( P<0.05). After the intervention, nurses' self motivation belief, task analysis, self-monitoring and regulation, self-evaluation and total score were significantly higher than those before the intervention ( P<0.05). Conclusion:The nursing management mode of magnetic nursing concept is of value in improving nurses' autonomous learning ability and critical thinking ability.

Objective This study aims to investigate the gene expression of P2X7 receptor in retinal ganglion cell line (RGC-5),and to design and select the small interfering RNA (siRNA) which can specifically and effectively downregulate P2X7 receptor expression.Methods The mRNA and protein expressions of P2X7 receptor in RGC-5 cells were examined by real-time polymerase chain reaction (qRT-PCR),Western blot and Immunofluorescence,and compared with those of mouse retina and other tissues.Three P2X7 receptor-specific double stranded siRNAs (P2X7-siRNA-1-3) were designed and delivered into RGC-5 cells by riboFECTTM CP.60 hours after transfection,the expression level of P2X7 receptor was analyzed by qRT-PCR,Western blot and Immunofluorescence.Results The expression of P2X7 receptor was detected in both RGC-5 cell line and mouse retina,and the receptor was mainly expressed in the nucleus and cytoplasm of RGC-5 cells.P2X7-siRNA-3 can effectively down-regulate the mRNA and protein expression of P2X7 at the same time.Conclusions RGC-5 cell line can serve as a good model for studying the biological function of P2X7 receptor in retinal ganglion cells in vitro.We have managed to design and synthesize the siRNA pair that specifically and effectively lowering P2X7 receptor expression.The current study has laid the foundation for future investigations on treating glaucomatous retinopathy by downregulation of P2X7 receptor.

Objective To investigate the relationships between serum osteocalcin (OC) levels and glycometabolism markers in nondiabetic post-traumatic male patients.Methods Populaitons were selected at the Department of Emergency Medicine of Shanghai Jiao Tong University Affiliated Sixth People's Hospital from October 2017 to February 2019.The age,injury severity score (ISS),and characteristic indicators were recorded.The inclusion criteria were age ≥ 18 years and blood collection time ＜ 24 h after the injury.The exclusion criteria were emergency surgery,acute brain trauma,and hemoglobin A1c (HbA1c) ≥ 6.0％.The patients were divided into two groups by fasting plasma glucose (FPG):stress hyperglycemia (SH) (FPG＞7.8 mmol/L) and nonstress hyperglycemia (NO-SH) (FPG ≤ 7.8 mmol/L) groups.The fasting venous blood samples were collected and examined.The characteristics and biochemical indicators in the two groups were compared statistically by LSD-t test,rank sum test and ANOVA,and the relationships between serum OC levels and glycometabolism markers were analyzed by partial correlation analysis.Results A total of 395 traumatic patients were enrolled and divided into the SH group (n=182) and NO-SH group (n=213).There were no differences in ISS,fasting insulin (FINS),and C-peptide (C-P) levels between groups.Age,HbAlc and FPG were higher (P=0.041,P=0.037,P＜0.01),while the OC level was lower (P=0.023),in the SH group than those in the NO-SH group.The serum OC level did not correlate with HbAlc,FPG,and FINS,but negatively correlated with C-P by partial correlation analysis (r=-0.262,P=0.008).The multivariate linear regression analysis showed that C-P was an independent factor affecting serum OC levels after trauma (β=-0.655,P=0.043).Conclusion A correlation existed between the serum OC level and glycometabolism markers in nondiabetic post-traumatic male patients.

BACKGROUND: Knee osteoarthritis (KOA) is a prevalent chronic joint disease caused by various factors. Mesenchymal stem cells (MSCs) therapy is an increasingly promising therapeutic option for osteoarthritis. However, the chronic inflammation of knee joint can severely impede the therapeutic effects of transplanted cells. Gelatin microspheres (GMs) are degradable biomaterial that have various porosities for cell adhesion and cell–cell interaction. Excellent elasticity and deformability of GMs make it an excellent injectable vehicle for cell delivery. METHODS: We created Wharton’s jelly derived mesenchymal stem cells (WJMSCs)-GMs complexes and assessed the effects of GMs on cell activity, proliferation and chondrogenesis. Then, WJMSCs loaded in GMs were transplanted in the joint of osteoarthritis mice. After four weeks, joint tissue was collected for histological analysis. Overexpressing-luciferase WJMSCs were performed to explore cell retention in mice. RESULTS: In vitro experiments demonstrated that WJMSCs loaded with GMs maintained cell viability and proliferative potential. Moreover, GMs enhanced the chondrogenesis differentiation of WJMSCs while alleviated cell hypertrophy. In KOA mice model, transplantation of WJMSCs-GMs complexes promoted cartilage regeneration and cartilage matrix formation, contributing to the treatment of KOA. Compared with other groups, in WJMSCs+GMs group, there were fewer cartilage defects and with a more integrated tibia structure. Tracking results of stable-overexpressing luciferase WJMSCs demonstrated that GMs significantly extended the retention time of WJMSCs in knee joint cavity. CONCLUSION Our results indicated that GMs facilitate WJMSCs mediated knee osteoarthritis healing in mice by promoting cartilage regeneration and prolonging cell retention. It might potentially provide an optimal strategy for the biomaterial-stem cell based therapy for knee osteoarthritis.

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 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.