Objective To perform mutation analysis of survival motor neuron gene 1 (SMN1 in two spinal muscular atrophy (SMA) patients and their parents to evaluate the effects of the two SMN1 gene mutations on the transcript levels of the gene and preliminarily predict their effects on the structure and function of SMN protein.Methods Mutation analysis of SMN1 gene was carried out by multiplex ligationdependent probe amplification,reverse transcript-polymerase chain reaction (RT-PCR) and cloning sequencing.Transmission of the mutations was confirmed by the mutation analysis in patients' parents.The full-length SMN1 (SMN1-fl) transcript levels of the patients carrying these subtle mutations were detected using quantitative RT-PCR.Results The two patients were diagnosed as SMA Ⅱ and SMA Ⅲ.They carried p.Val19GlyfsX21 and p.Ala2Gly SMN1 mutations in SMN1 gene,respectively.Both of the two mutations were originated from their fathers.Compared with the healthy individuals (23.5 ± 4.9),the two patients had a significant reduction in the level of SMN1-fl transcripts (t =3.322,P =0.011 (p.Ala2Gly) ;t =6.964,P =0.000 (p.Val19GlyfsX21)).However,compared with the healthy carriers (14.1 ±4.5),the patient with p.Ala2Gly mutation had no significant reduction in the level of SMN1-fl transcripts (13.9 ±3.6,t =0.058,P =0.955) ; however,the patient with p.Val19GlyfsX21 mutation had a significant reduction (4.9± 2.4,t =3.725,P =0.004).Conclusions Two SMN1 gene mutations are identified in our study.The mutation p.Val19GlyfsX21 is a novel mutation and p.Ala2Gly is firstly reported in Chinese SMA patients.p.Val19GlyfsX21 may possibly lead to decreased SMN1-fl mRNA by nonsense-mediated messenger RNA decay,however,p.Ala2Gly has no obvious effects on the amount of the SMN1-fl transcripts,indicating that its deleterious effect may be occurring at SMN protein level or the function of SMN protein.

Objective To analyze the distribution of common chromosomal karyotypes of patients with Turner syndrome (TS), and to explore the correlation between the age and height standard deviation scores (HSDS) on diagnosis.Methods Retrospective investigation was performed for the data of age and HSDS on diagnosis in 273 TS girls(≤ 18.0 years old)diagnosed by chromosomal karyotypes.The main statistical methods were analyzed with t-test and Pearson correlation test by using the SPSS 18.0 statistical software.Results (1) There were 4 kinds of common chromosomal karyotypes in the TS :45, X (87/273 cases,31.9％),46, X, i (Xq) (43/273 cases, 15.7％) ,45, X/46, X, i (Xq) (36/273 cases, 13.2％) and 45, X/46, XX (23/273 cases, 8.4％), respectively, the adolescent TS all had delayed puberty.For the cases with 45, X karyotypes ,3 cases presented mental retardation and 2 cases with organs deformity.(2)The patients with 45 ,X/46,X,i(Xq) karyotypes or with 46,X,i(Xq) karyotypes had the maximum(12.56 age) or the minimum(9.70 age) mean age on diagnosis, respectively, there was a significant difference between 2 groups (t =3.019, P =0.004).The maximum deviation from normal height was found in the patients with karyotypes of 46, X,i (Xq) (HSDS =-4.04), and the minimum deviation was in the patients with karyotypes of 45,X/46, XX (HSDS =-3.16), and there was a significant difference between 2 groups (t =-2.95, P =0.004).(3) More than 75.7％ of TS patients was diagnosed when their heights deviated above 3 SD,and their mean age on diagnosis was 12.10 age,which was 3 years later than those patients within 2 SD.(4) There was a significant negative correlation between the age and HSDS on diagnosis in the groups of common chromosomal karyotypes[45,X、46,X,i(Xq) and 45,X/46,XX] (r =-0.551,-0.560,-0.622,all P ＜ 0.01), except for the group with the 45, X/46, X, i (Xq).Conclusions (1) In this study, the consti-tuent ratios of these 4 common chromosomal karyotypes were different from those in Europe and America's.(2)Patients with 45 ,X may have more severe symptoms than others.(3)The mean age on diagnosis was at least 3.0 years earlier when considered HSDS below-2.00 as an indicator for chromosomal karyotype screening,which would facilitate earlier diagnosis.

Objective To measure the present situation of medical students' learning adaptability and find the influencing factors in order to revise Learning Adaptability Scale for medical students.Methods A stratified sampling method was used to collect 1 180 medical students from Harbin Medical University.Using the internal consistency reliability test,the reliability of the revised student learning adaptability scale was verified.Five common factors were extracted by the exploratory factor analysis of the principal analysis method,and Logistic regression was used to analyze the influencing factors of medical student learning adaptability.Results The revised Student Learning Adaptability Scale (Cronbach's Alpha=0.914) consists of 27 measurement items.It includes five dimensions,namely self-directed learning,information utilization,environment choice,stresses response and goal orientation.The results showed that the adaptability of medical students was moderate (3.28 ± 0.52),and the influencing factors included job position (OR =1.496,95％ CI=1.114-2.009),academic achievement (OR =1.638,95 ％ CI=1.386-1.936),satisfaction with learning (OR=2.160,95％CI=1.745-2.673),professional satisfaction (OR=1.369,95％CI=1.092-1.718),professional interest (OR =1.426,95％ CI=1.186-1.715) and employment prospects (OR =1.526,95％ CI=1.251-1.862).Conclusion The reliability and validity of the Student Learning Adaptability Scale is appropriate.Medical students' learning adaptability is influenced by many factors.

OBJECTIVETo establish a hyperphenylalaninemia related genes screening method using Ion Torrent Personal Genome Machine (PGM) for early detection and differential diagnosis of hyperphenylalaninemia (HPA).

METHODSThree children with known HPA mutations and a healthy control were used for setting up the method. Ten children with HPA with known mutations were recruited for validating the method. Ion Ampliseq PCR was used to amplify the 5' and 3' untranslated region, coding sequence, and flanking introns of PAH, GCH1, PTS, QDPR, and PCBD1 genes. After the enrichment with the Ion OneTouch system, the products were sequenced by PGM. Data from the PGM were processed with Torrent Suite v2.2 software package. All variations were confirmed by Sanger sequencing.

RESULTSFor the 4 samples, the PGM output was 94.22 Mb, with approximately 99.5% of reads mapping to the target regions. Among these samples, we detected 74 variations (28 positions) including 6 known mutations. Compared with database and results of Sanger sequencing, 55 (18 positions) polymorphisms and 13 (4 positions) false positive calls were confirmed. For the 10 samples, all the known mutations were successfully identified.

CONCLUSIONIon Torrent PGM sequencing is suitable for screening genetic mutation underlying HPA from the perspective of metabolic pathways, which can meet the clinical demand for individualized diagnosis and treatment.

Objective:To explore application status and development trend of spinal muscular atrophy (SMA) genetic diagnosis technology based on the national rare diseases registry system of China.Method:A total of 200 SMA children registered at the Capital Institute of Pediatrics from July 2016 to December 2018 were included in this retrospective cross-sectional survey. The basic data, clinical subtypes, genotypes, and related genetic testing information of SMA children were obtained by checking SMA registration information, genetic testing reports, and also by telephone follow-up. The patient number and the composition of different genetic diagnosis technologies were analyzed by the stratification of genetic testing at various time. The correlation between the proportion of genetic diagnosis technology and genetic testing time was analyzed with Pearson correlation analysis.Result:There were 3 SMA cases with incomplete data, the remaining 197 SMA cases were included in this study. There were 37 (18.8%), 115 (58.4%) and 45 (22.8%) patients with type Ⅰ, Ⅱ and Ⅲ SMA, respectively. There were 185 cases of SMN1 homozygous deletion (93.9%), and 12 cases with compound heterozygotes (6.1%). Seven SMA-related genetic technologies were used from 2004 to 2017. MLPA accounted for 54.1% (100/185) used approach, followed by PCR-RFLP and first-generation sequencing, which accounted for 22.7% (42/185) and 10.3% (19/185), respectively. Nine, 6, 5 and 4 cases were tested with AS-PCR, qPCR, WES and DHPLC, respectively (2.2%-4.9%). The proportion of MLPA increased gradually since 2010 ( r=0.95, P<0.05), while PCR-RFLP declined gradually since 2004 ( r=-0.99, P<0.05). No correlation was found between technology and testing time for other genetic testing technologies ( P>0.05). The proportion of quantitative genetic technologies (MLPA, qPCR and DHPLC) increased gradually since 2010 ( r=0.94, P<0.05), and qualitative genetic technologies (PCR-RFLP, first-generation sequencing, AS-PCR and WES) decreased gradually since 2004 ( r=-0.94, P<0.05). The duplication detection rates of homozygous deletion and compound heterozygous mutation were 12.4% (23/185) and 41.7% (5/12), respectively (χ 2=5.86, P<0.05). During 2008-2015, the proportion of "the reports of both copy numbers of SMN1 gene and SMN2 gene" increased from 56.8% (21/37) in 2008-2015 to 69.1% (56/81) in 2016-2017. Conclusion:Genetic diagnosis of SMA has gradually developed from qualitative detection technology to quantitative detection technology, such as MLPA and qPCR, in China. In more and more SMA quantitative test reports, quantitative results of SMN2 gene are also provided in addition to quantitative results of SMN1 gene.

Innovative self-efficacy is the degree of self-confidence in the individual's ability to per-form innovative activities. Although the theory of innovation self-efficacy is shorter, but as an important indicator of innovation ability measurement, it has been accepted by scholars in various countries, and innovative self-efficacy provides a new perspective for the cultivation of innovative talents. The research of innovation self-efficacy is still the initial stage. Chinese and foreign scholars have made some progress in measuring tools, antecedents, aftereffect and development, but there are still obvious differences and defi-ciencies,and the research results are not abundant.The future research will focus on the measurement tools, influencing factors and research direction of three aspects of systematic research to improve the theory of innovation self-efficacy.

The theoretical framework classifies the ideal types of graduate supervisors,which is based on "the attention that the supervisor pays on academic research" and "the attention that the supervisor pays on clerical work".The author elaborates the characteristics of each type of supervisor and enumerates some possible causes for the different types of supervisors.According to the occupational characteristics of the graduate supervisors in China and taking into account the two influence factors as "personal ambition" and "relative deprivation",a theoretical model of supervisor type transformation model based on academic research and clerical work is presented and the causes of this transformation are also briefly analyzed,which provides the theoretical basis for the related research and management practice of graduate supervisors.

Objective:To investigate the coverage rate and the adverse reactions of National Immunization Program vaccines in children with spinal muscular atrophy (SMA).Methods:A cross-sectional retrospective cohort study was carried out from July 2016 to June 2019, 192 children (116 boys and 76 girls) with SMA registered by Capital Institute of Pediatrics and 191 healthy children (115 boys and 76 girls) vaccinated in Chaoyang Olympic Village Community Health Service Center from July 2016 to December 2018 were included. Questionnaire survey was designed to investigate the vaccination coverage rate and associated adverse events. The t-test and χ 2 test were used to compare the difference between SMA patients and healthy children. Results:The coverage rate of age-appropriate immunization in SMA children was 62.0% (119/192) in general, and were 52.2% (12/23), 55.7% (68/122), and 83.0% (39/47) for SMA type 1-3 patients, respectively (χ 2=12.23, P=0.002). The vaccination coverage rates of Bacillus Calmette-Guerin (BCG) vaccine, the 3 rd dose of hepatitis B, the 3 rd dose of polio, the 3 rd dose of diphtheria-pertussis-tetanus, the 1 st dose of meningococcal polysaccharide group A, the 1 st dose of measles or measles and rubella vaccine, the 1 st dose of Japanese encephalitis vaccine, hepatitis A, measles-mumps-rubella, and group A+C meningococcal polysaccharide vaccine were 100.0% (192 cases), 94.3% (181 cases), 81.8% (157 cases), 88.5% (170 cases), 83.9% (161 cases), 76.6% (147 cases), 80.2% (154 cases), 68.2% (131 cases), 69.8% (134 cases), 54.7% (105 cases), respectively. Among the 73 patients who did not have their planned immunization completed, 57 cases (78.1%) gave up the vaccination due to parents′ concern of potential aggravation of their disease, and 16 cases (21.9%) had the plan discontinued by the immunization department because of the disease. Fever, local redness and swelling were the most common side-effects after vaccination both in SMA patients and healthy children (19.8% (38/192) vs. 18.8% (36/191) , χ 2=0.055, P=0.815). The main abnormal reactions of vaccination were rash and neurovascular edema, without significant difference between these two groups (2.6% (5/192) vs. 3.7% (7/191), χ 2=0.355, P=0.551). The coverage rate of Influenza and pneumococcal vaccine in SMA patients were 22.4% (43 cases) and 31.8% (61 cases), respectively. The incidence of pneumonia in the SMA patients decreased from 59.0% (23/39) to 41.0% (16/39) after vaccination. And none of the Influenza vaccinated patients had the flu in the year of vaccination. Conclusions:The coverage rate of National Immunization Program vaccines in the SMA children is low, especially in type 1 SMA patients, which is mainly due to their guardians′ concern of potential adverse events, even though the incidence of adverse reactions is similar in SMA patients and healthy children. Influenza and pneumococcal vaccine can reduce the risk of pneumonia and flu in children with SMA effectively.

Objective:To analyze the significance of HBV DNA below the lower detection limit of HBV RNA levels after long-term nucleos(t)ide analogues (NAs) antiviral therapy in patients with hepatitis B virus cirrhosis.Methods:97 cases with hepatitis B virus cirrhosis treated with NAs antiviral therapy for at least 3 years between May 2018 to July 2019 were selected. High-sensitivity HBV DNA (<20 IU/ml), alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyltransferase (GGT), HBsAg, HBeAg and HBV RNA at least twice every 6 months were detected. According to Child-Pugh classification, HBeAg, HBsAg level, and HBV RNA level intergroup comparison was performed. Rank sum test, χ2 test and linear regression analysis were performed on the data. Results:Compared with the HBV RNA level of child-Pugh class A patients, the HBV RNA level of Child-Pugh class B+C patients were significantly higher [4.1 (0,4.9) log 10 copies/ml and 2.0 (0,3.5) log 10 copies/ml], and the difference was statistically significant ( Z=2.370, P<0.05). According to different HBeAg levels, they were divided into HBeAg positive and negative group, and the quantitative comparison of HBV RNA levels between the two groups were 2.0 (0, 4.5) log 10 copies/ml and 1.0 (1.0, 2.0) log 10 copies/ml, respectively, and the difference was statistically significant ( Z=3.233, P<0.05). According to different HBsAg levels, they were divided into three groups: HBsAg≤100 IU/ml, 100

As an important industrial chemical, isoprene is mainly used as a precursor for synthetic rubbers. In addition, it also has wide applications in the field of pharmaceutical and chemical intermediates, food, adhesives and aviation fuel. Compared with conventional petrochemical routes, production of isoprene in microbial systems has been the research focus considering environment friendly and sustainable development features. This article summarizes the metabolic pathways and key enzymes of isoprene biosynthesis, reviews current methods and strategies in improving isoprene production of Escherichia coli, and also gives some basic ideas and expectation.
Butadienes ; Escherichia coli ; Hemiterpenes ; biosynthesis ; Industrial Microbiology ; Metabolic Engineering ; Metabolic Networks and Pathways ; Pentanes