Objective To explore the value of curvature value of liver surface nodularity(LSN)based on MRI in evaluating liver function in patients with liver cirrhosis.Methods A retrospective analysis was made on the patients who underwent upper abdomen MR examination at 3.0T.The normal liver function patients and cirrhosis patients were enrolled in the study and then the Child-Pugh score of the patients were calculated.The patients were divided into three groups:normal liver group,compensated cirrhosis group and decompensated cirrhosis group.The water phase imaging of 3D modified Dixon fast field echo(mDixon-FFE)sequence was copied in DICOM format.ITK software was used to manually draw the full-thickness liver edge by two observers.The curvature value of LSN was obtained by using matlab self compiled code for follow up analysis.Kruskal-Wallis H test was used to compare the curvature value between the groups.The receiver operating characteristic(ROC)curve was drawn and the area under the curve(AUC)was obtained.Spearman test was used for the correlation analysis.Results The curvature values of LSN among the normal liver,compensated cirrhosis and decompensated cirrhosis groups gradually increased(P<0.05).Comparing normal liver with compensated cirrhosis,the AUC of diagnosing compensated cirrhosis was 0.84,with the sensitivity of 72.7%and the specificity of 89.3%.Comparing compensated cirrhosis with decompensated cirrhosis,the AUC of diagnosing decompensated cirrhosis was 0.91,with the sensitivity of 80%and the specificity of 90.9%.There was a moderate positive correlation between the curvature value of LSN and liver function score in patients with cirrhosis(r=0.63,P=0.002).Conclusion The curvature value of LSN based on MRI can be used for preliminary evaluation of liver function of liver cirrhosis,with the AUC more than 0.80 and higher sensitivity and specificity.

Objective To assess the alterations of negative functional connectivity(FC),its relationship with clinical symptoms,and its potential value in schizophrenia(SZ).Methods Resting-state functional magnetic resonance imaging(rs-fMRI)data were acquired from patients with SZ and healthy controls(HC).For each participant,the whole brain image was first divided into 272 regions and then the FC between each pair of these regions was calculated using Pearson's correlation coefficient.Group-level negative FCs were identified using permutation test for each group.Each of the identified negative FCs was then compared between patients and controls to identify the altered negative FCs.Then,Spearman rank correlation was adopted to examine the relationship between the altered negative FCs and clinical variables.Finally,to evaluate the diagnostic value of negative FC in SZ,a multivariate pattern analysis(MVPA)was performed to distinguish between SZ and HC based on negative FCs.Results Ninety-one patients with SZ and 91 HC were included in this study,and 207 negative FCs in total were identified.Among the identified 207 negative FCs,12(constituting 5.80％of the total 207 negative FCs)were significantly altered in SZ compared with HC(Bonferroni correction,P<0.05),of which 11 were significantly decreased(i.e.,closer to 0)in SZ.The correlation analyses identified 2 significant associations-one was between a negative FC and the total score of the psychotic symptoms rating scales-auditory hallucinations(r=-0.24,P=0.02)and the other was between a negative FC and the weighted total score of the scale for the assessment of thought,language,and communication(r=0.26,P=0.01).Furthermore,the model for distinguishing between SZ and HC based on negative FCs achieved a classification accuracy of 72.6％that was significantly higher than chance-level accuracy(permutation test,P<0.001).Conclusion Negative FCs are altered in patients with SZ.Given that negative FCs are associated with clinical symptoms,thus they may serve as an imaging biomarker for assisting the diagnosis of SZ.

Objective:To investigate whether anxiety state and anxiety trait modulate specifically pain-induced brain responses by comparing the brain activations induced by painful stimulation and those by tactile stimulation in college students with different levels of anxiety state or anxiety trait.Methods:From April 2017 to September 2017, sixty-two college students were tested in Tianjin Medical University General Hospital.Each subject’s anxiety trait and anxiety state were assessed by the state-trait anxiety inventory (STAI) prior to the fMRI experiment.During the fMRI experiment, each subject received painful and tactile stimuli.Their brain responses to each stimulus were collected by the MRI scanner, and the perceived intensity rating of each stimulus was collected using the visual analogue scale (VAS). The pain and tactile brain activation values of subjects with different state anxiety levels and different trait anxiety levels were compared.The fMRI brain activation was detected using general linear model.For each type of anxiety (state or trait), two-way ANOVA was performed to detect the interaction between anxiety level and stimulus modality on brain responses and two-sample t-tests were performed to analyze the specific form of interaction in each brain region. Results:There were interactions between state anxiety and stimulation modality on the activation intensity of bilateral posterior parietal lobe, dorsolateral prefrontal lobe and other brain regions( P<0.05, cluster-level FWE corrected) .The brain responses to tactile stimuli (5.66±0.65) in these areas were significantly stronger than those to painful stimuli (1.24±0.55) in the group of middle-level anxiety state ( P<0.001), but no significant difference was found in the other two groups (both P>0.05). For anxiety trait, a few brain areas in bilateral occipital cortex showed significant interactions between anxiety level and stimulus modality.The brain responses to tactile stimuli (8.38±1.00) in these areas were significantly stronger than those to painful stimuli (3.19±1.12) in the group of high-level anxiety trait ( P=0.001), but no significant difference was found in the other two groups (both P>0.05). Conclusion:The modulatory effects of anxiety (both state and trait) on brain responses are different between painful and tactile conditions.It provides important evidence for unveiling the brain mechanisms of the specific modulation of anxiety on pain, and suggests that patients' anxiety trait and anxiety state should be considered during clinical treatment of pain.

Objective:To investigate the molecular characteristic and antimicrobial resistance of Staphyloco- ccus aureus ( S. aureus) isolated from children with pneumonia, in order to provide the evidence for clinical diagnosis and treatment. Method:s The S. aureus strains isolated from children diagnosed as S. aureus pneumonia in the Beijing Children′s Hospital, Capital Medical University, between January 2016 and March 2017 were collected.Methicillin-resistant S. aureus(MRSA)and Methicillin-susceptible S. aureus(MSSA)were identified using the cefoxitin disc method and the detection of the mecA gene. S. aureus isolates were characterized by multilocus sequence typing (MLST) and Staphylococcal protein A (spa) typing, and MRSA strains were characterized by Staphylococcal chromosome cassette (SCC mec) typing.Besides, 21 superantigens (SAgs) genes, panton-valentine leucocidin (PVL) genes, adhesion genes fnbb and cna were detected by PCR; E-test was used to detect in vitro drug sensitivity of 14 antibiotics. Result:s A total of 42 S. aureus were collected, and 21 isolates were MSSA, the same to MRSA, while MSSA strains had relatively dispersed typing, with ST25-t078 (14.2%) as the most common one.ST59-SCC mecⅣa-t437 (71.4%) were the most predominant clones of MRSA.Of the 42 isolates, 36 strains (85.7%) had at least 1 superantigen gene, and sek- seq (21.4%) was the main virulence genotype.The ratio of pvl in MRSA strains (52.3%)was significantly higher than that in MSSA strains (14.2%), while the detection rate of fnbB and cna in MRSA(9.5%, 9.5%) was significantly lower than that in MSSA(42.8%, 47.6%), and the differences were statistically significant (all P<0.05). Ninety point four percent (38/42 strains) of the S. aureus isolates were multidrug resistant. Conclusions:In children with S. aureus pneumonia, MRSA has a high detection rate, and its dominant clonotype is ST59-SCC mecⅣa-t437.The pre-valence of superantigen genes and the multidrug resistant rate of S. aureus are relatively high.MRSA strains often carry pvl, while MSSA strains usually carry fnbB and cna gene.

The epidemic of corona virus disease 2019 (COVID-19) is still ongoing, and infections among health care workers are not uncommon. How to complete the diagnosis and treatment of orthopaedic diseases and prevent the spread of the epidemic is a great challenge for orthopaedic surgeons. On the basis of exposure history and medical conditions of orthopaedic patients, the hierarchical control is very important for reduction of the exposure for the medical staff and patients. In order to ensure medical safety and reduce the consumption of materials for the epidemic prevention, we classified the hospitalized orthopaedic patients into three classes and six levels, to provide effective references for all levels of hospitals in orthopaedic clinical work.

Objective:To obtain the genome sequences of SARS-CoV-2 in respiratory specimens in Guangdong Province with next-generation sequencing (NGS) and analyze the factors influencing sequencing.Methods:Eight upper and lower respiratory tract specimens were collected from patients with SARS-CoV-2 infection in Guangdong Province in January 2020. RNA library construction was used to obtain the genome sequences of SARS-CoV-2. A bio-informatics software package (CLC Genomics Workbench 12.0) was used to analyze and compare the genomic sequences.Results:Five SARS-CoV-2 genome sequences were obtained from the eight specimens and two were obtained from lower respiratory tract specimens. The nucleotide homology to SARS-CoV-2 was 97.74%-99.90%. The Ct values were lower, while the sequencing depth, coverage, relative abundance and genome integrity were higher in sequencing the SARS-CoV-2 in lower respiratory tract specimens.Conclusions:The low Ct value of SARS-CoV-2 in the samples was good for sequencing.

Objective:To understand the genetic variation and epidemiological characteristics of human respiratory syncytial virus (HRSV) in Guangzhou.Methods:Nasopharyngeal swabs specimens were collected from 0-6 year old children hospitalized with acute respiratory infection, then HRSV was tested and genotyped by RT-PCR. Phylogenetic tree was bulit using MEGA 6.0 software. NetNGlyc 1.0 server was used to predict the potential N-linked glycosylation sites.Results:A total of 1 225 nasopharyngeal specimens were collected, including 783 males and 442 females. The median ( P25, P75) age was 8 (3, 24) months. Among the 209 HRSV-positive cases (17.06%), 117 cases (55.98%) were HRSV-A and 92 cases (44.02%) were HRSV-B. The two distinct subgroups (HRSV-A and HRSV-B) alternately played dominant role to cause HRSV infection and exchange almost once every two years. The HRSV prevalence rate decreased with age. The HRSV-positive rate among children under 2 years old was 18.83% (196 cases), accounting for 93.78% of the total positive cases. There were 32 HRSV positive cases co-infected with at least one respiratory virus, with the co-infection rate of 15.31%. Phylogenetic tree analysis of the second hypervariable region (HVR2) of the G protein classified the HRSV-A specimens into ON1 ( n=62) and NA1 ( n=2) genotypes while all HRSV-B specimens belonged to BA genotype ( n=53). The HVR2 of the G protein varied in using stop condon, amino acid substitutions, glycosylation sites. Conclusion:Children under 2 years old were the high risk population of HRSV infection in Guangzhou. ON1 genotype turned into a primary genetype of the HRSV-A subgroup while BA genotype dominated the HRSV-B subgroup. A greater diversification of amino acid substitutions, and some deletion and insertion of glycosylation sites embodied the polymorphism of G protein as main protective antigen.

Objective:To understand the genetic variation and epidemiological characteristics of human respiratory syncytial virus (HRSV) in Guangzhou.Methods:Nasopharyngeal swabs specimens were collected from 0-6 year old children hospitalized with acute respiratory infection, then HRSV was tested and genotyped by RT-PCR. Phylogenetic tree was bulit using MEGA 6.0 software. NetNGlyc 1.0 server was used to predict the potential N-linked glycosylation sites.Results:A total of 1 225 nasopharyngeal specimens were collected, including 783 males and 442 females. The median ( P25, P75) age was 8 (3, 24) months. Among the 209 HRSV-positive cases (17.06%), 117 cases (55.98%) were HRSV-A and 92 cases (44.02%) were HRSV-B. The two distinct subgroups (HRSV-A and HRSV-B) alternately played dominant role to cause HRSV infection and exchange almost once every two years. The HRSV prevalence rate decreased with age. The HRSV-positive rate among children under 2 years old was 18.83% (196 cases), accounting for 93.78% of the total positive cases. There were 32 HRSV positive cases co-infected with at least one respiratory virus, with the co-infection rate of 15.31%. Phylogenetic tree analysis of the second hypervariable region (HVR2) of the G protein classified the HRSV-A specimens into ON1 ( n=62) and NA1 ( n=2) genotypes while all HRSV-B specimens belonged to BA genotype ( n=53). The HVR2 of the G protein varied in using stop condon, amino acid substitutions, glycosylation sites. Conclusion:Children under 2 years old were the high risk population of HRSV infection in Guangzhou. ON1 genotype turned into a primary genetype of the HRSV-A subgroup while BA genotype dominated the HRSV-B subgroup. A greater diversification of amino acid substitutions, and some deletion and insertion of glycosylation sites embodied the polymorphism of G protein as main protective antigen.

Objective: To study the clinical and molecular characteristics of Staphylococcus aureus(S.aureus ) isolated from neonates of Beijng Children′s Hospital. Methods: The clinical information of S. aureus infection in newborns of Beijing Children′s Hospital from February 2016 to January 2017 was collected.The molecular biological characteristics of S. aureus isolates were detected.Methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus(MSSA)were identified, using the cefoxitin disc method and the detection of the mecA gene.Multilocus sequence typing(MLST)and spa typing were analyzed using the PCR, and the staphylococcal chromosomal cassette mec(SCCmec) type was analyzed for the MRSA isolates.Eleven adhesion gene and three virulence genes(pvl, psma, hlα )were also detected by PCR.Antimicrobial susceptibility testing was performed by agra dilution method or E-test method. Results: The total of 57 cases of neonatal S. aureus infection were collected during the study.The most common clinical diagnosis was 38 cases (66.7%) of pneumonia and 28 cases (49.1%) of skin infection syndrome (SSTI). There were 31 cases (54.4%) with MRSA infection and 26 cases (45.6%) with MSSA infection.The proportion of SSTI in the MRSA group (64.5%) and the infection of more than 2 sites (61.3%, 19/31) were significantly higher than those in the MSSA group (30.8%, 8/26 and 23.1%, 6/31). There were 16 MLST types and 29 spa types, the most common ones were ST59 (40.4%) and t437 (33.33%), respectively.The most common popular clones of MRSA and MSSA were ST59-SCCmecIVa-t437 (54.8%) and ST22-t309, respectively(11.5%). The sdrE carrying rate of MRSA was higher than that of MSSA, while the sdrD and cna carrying rates were lower than those of MSSA (P<0.05). The other adhesion and virulence gene carrying rates were not significantly different between the two strains.The multi-drug resistance rate of all strains was 61.4%(35/57). Except for lactam antibiotics, the most common resistant phenotypes of MRSA and MSSA were ERY-CLI, accounting for 74.2% and 26.9%, respectively. Conclusion The main types of neonatal S. aureus infection in our hospital were pneumonia and SSTI.SSTI and multi-site infections of MRSA infection are more common.MRSA and MSSA isolates have clonal dissemination characteristics.The most common clones are ST59-SCCmecIVa-t43 and ST22-t309, which show no significant differences in the status of carrying virulence factors between them.The multi-drug resistance rate of neonatal S. aureus isolates is higher.