Metabolomics and Biomarkers for Paroxysmal and Persistent Atrial Fibrillation.

BACKGROUND: Atrial fibrillation (AF) is the most common type of arrhythmia worldwide and is associated with serious complications. This study investigated the metabolic biomarkers associated with AF and the differences in metabolomics and associated metabolic biomarkers between paroxysmal AF (AFPA) and persistent AF. METHODS AND RESULTS: Plasma samples were prospectively collected from patients with AF and patients in sinus rhythm with negative coronary angiography. The patients were divided into 3 groups: AFPA, persistent AF, and sinus rhythm (N=54). Metabolomics (n=36) using ultra-high-performance liquid chromatography mass spectrometry was used to detect differential metabolites that were validated in a new cohort (n=18). The validated metabolites from the validation phase were further analyzed by receiver operating characteristic. Among the 36 differential metabolites detected by omics assay, 4 were successfully validated with area under the curve >0.8 (P<0.05). Bioinformatics analysis confirmed the enrichment pathways of unsaturated fatty acid biosynthesis, glyoxylate and dicarboxylate metabolism, and carbon metabolism. Arachidonic acid was a potential biomarker of AFPA, glycolic acid and L-serine were biomarkers of AFPA and persistent AF, and palmitelaidic acid was a biomarker of AFPA. CONCLUSIONS: In this metabolomics study, we detected 36 differential metabolites in AF, and 4 were validated with high sensitivity and specificity. These differential metabolites are potential biomarkers for diagnosis and monitoring of disease course. This study therefore provides new insights into the precision diagnosis and management of AF.

Efeitos de uma modalidade de educação em saúde baseada na teoria do comportamento planejado sobre o estilo de vida pós-operatório de pacientes com câncer cervical / Efectos de una modalidad de educación para la salud basada en la teoría del comportamiento / Effects of a health education mode based on the theory of planned behavior on the postoperative lifestyle of patients with cervical cancer

Resumo Objetivo Desenvolver uma modalidade de educação em saúde baseado na teoria do comportamento planejado (TCP) e explorar sua influência no estilo de vida pós-operatório de pacientes com câncer cervical. Métodos Um total de 122 pacientes diagnosticados de janeiro de 2019 a junho de 2020 foram divididos nos grupos Controle e Educação (n = 61) usando uma tabela de números aleatórios. O grupo Controle recebeu educação em saúde tradicional após a cirurgia, enquanto o grupo Educação recebeu educação em saúde baseada em TCP após a cirurgia e seus dados gerais, adesão à medicação, adesão à dieta, tempo de alta, incidência de complicações, estilo de vida, qualidade de vida (QV) e estado mental antes e depois da cirurgia foram comparados. Resultados Não foram encontradas diferenças significativas nos dados gerais, pontuação de estilo de vida pré-operatório, pontuação de qualidade de vida e pontuação de estado mental entre os dois grupos (P>0,05). No grupo Educação, as pontuações de adesão à medicação e adesão à dieta foram significativamente maiores do que no grupo Controle, enquanto o tempo de alta e a incidência total de complicações foram mais precoces e menores do que no grupo Controle (P <0,05). Após a cirurgia, as pontuações de autorrealização, relacionamento interpessoal, nutrição, atividade física, responsabilidade pela saúde, gestão do estresse, dimensão física, dimensão social/familiar, dimensão emocional e dimensão funcional aumentaram significativamente, enquanto as pontuações do termômetro de sofrimento e da lista de problemas diminuíram em ambos os grupos, e a melhora nas pontuações foi maior no grupo Educação do que o grupo Controle (P <0,05). Conclusão A modalidade de educação em saúde baseada na TCP pode melhorar a adesão ao tratamento pós-operatório, reduzir as complicações pós-operatórias e melhorar o estilo de vida, a qualidade de vida e o estado mental de pacientes com câncer cervical.

Resumen Objetivo Elaborar una modalidad de educación para la salud basada en la teoría del comportamiento planeado (TCP) e investigar su influencia en el estilo de vida posoperatorio de pacientes con cáncer cervical. Métodos Un total de 122 pacientes diagnosticados de enero de 2019 a junio de 2020 fueron divididos entre los grupos Control y Educación (n=61) por medio de una planilla de número aleatorios. El grupo Control recibió educación para la salud tradicional luego de la cirugía, mientras que el grupo Educación recibió educación para la salud basada en la TCP después de la cirugía; se compararon los datos generales, la adherencia a la medicación, la adherencia a la dieta, el tiempo de alta, la incidencia de complicaciones, el estilo de vida, la calidad de vida (CV) y el estado mental antes y después de la cirugía. Resultados No se encontraron diferencias significativas entre los dos grupos en datos generales, puntaje de estilo de vida preoperatorio, puntaje de calidad de vida y puntaje de estado mental (P>0,05). En el grupo Educación, los puntajes de adherencia a la medicación y adherencia a la dieta fueron significativamente más altos que en el grupo Control; mientras que el tiempo de alta fue anterior y la incidencia total de complicaciones fue menor que en el grupo Control (P <0,05). Después de la cirugía, los puntajes de autorrealización, relaciones interpersonales, nutrición, actividad física, responsabilidad por la salud, gestión del estrés, dimensión física, dimensión social/familiar, dimensión emocional y dimensión funcional aumentaron significativamente; mientras que los puntajes del termómetro de sufrimiento y de la lista de problemas disminuyeron en ambos grupos y la mejora de los puntajes fue mayor en el grupo Educación que en el grupo Control (P <0,05). Conclusión La modalidad de educación para la salud basada en la TCP puede mejorar la adherencia al tratamiento posoperatorio, reducir las complicaciones posoperatorias y mejorar el estilo de vida, la calidad de vida y el estado mental de paciente con cáncer cervical.

Abstract Objective To develop a health education mode based on the theory of planned behavior (TPB), and to explore the influence of this mode on the postoperative lifestyle of patients with cervical cancer. Methods A total of 122 patients diagnosed from January 2019 to June 2020 were divided into control and education groups (n=61) using a random number table. Control group received traditional health education after operation, while education group was given TPB-based health education after operation. Their general data, medication compliance, dietary compliance, discharge time, incidence of complications, lifestyle, quality of life (QOL) and mental state before and after operation were compared. Results No significant differences were found in general data, preoperative lifestyle score, QOL score and mental state score between the two groups (P>0.05). In education group, the medication compliance and dietary compliance scores were significantly higher than those in control group, while the discharge time and the total incidence of complications were earlier and lower than those in control group (P<0.05). After operation, the scores of self-realization, interpersonal relationship, nutrition, physical activity, health responsibility, stress management, physical dimension, social/family dimension, emotional dimension and functional dimension significantly rose, while the distress thermometer and problem list scores declined in both groups, and education group had better improvement in scores than control group (P<0.05). Conclusion Theory of planned behavior health education mode can improve the postoperative treatment compliance, reduce postoperative complications, and ameliorate the lifestyle, quality of life and mental state of patients with cervical cancer.

Interplay between oceanic subduction and continental collision in building continental crust.

Generation of continental crust in collision zones reflect the interplay between oceanic subduction and continental collision. The Gangdese continental crust in southern Tibet developed during subduction of the Neo-Tethyan oceanic slab in the Mesozoic prior to reworking during the India-Asia collision in the Cenozoic. Here we show that continental arc magmatism started with fractional crystallization to form cumulates and associated medium-K calc-alkaline suites. This was followed by a period commencing at ~70 Ma dominated by remelting of pre-existing lower crust, producing more potassic compositions. The increased importance of remelting coincides with an acceleration in the convergence rate between India and Asia leading to higher basaltic flow into the Asian lithosphere, followed by convergence deceleration due to slab breakoff, enabling high heat flow and melting of the base of the arc. This two-stage process of accumulation and remelting leads to the chemical maturation of juvenile continental crust in collision zones, strengthening crustal stratification.

Current trends in optimal medical therapy after PCI and its influence on clinical outcomes in China.

BACKGROUND: Limited data were available on the current trends in optimal medical therapy (OMT) after PCI and its influence on clinical outcomes in China. We aimed to evaluate the utilization and impact of OMT on the main adverse cardiovascular and cerebrovascular events (MACCEs) in post-PCI patients and analyzed the factors predictive of OMT after discharge. METHODS: We collected data from 3812 individuals from 2016.10 to 2017.09 at TEDA International Cardiovascular Hospital. They were classified into an OMT group and a non-OMT group according to their OMT status, which was defined as the combination of dual antiplatelet therapy, statins, ß-blockers, angiotensin-converting enzyme inhibitors or angiotensin receptor blockers after PCI. Multivariable Cox regression models were developed to assess the association between OMT and MACCEs, defined as all-cause mortality, nonfatal myocardial infarction, stroke, and target vessel revascularization. A logistic regression model was established to analyze the factors predictive of OMT. RESULTS: Our results revealed that the proportion of patients receiving OMT and its component drugs decreased over time. A total of 36.0% of patients were still adherent to OMT at the end of follow-up. Binary logistic regression analysis revealed that baseline OMT (P < 0.001, OR = 52.868) was the strongest predictor of OMT after PCI. The Cox hazard model suggested that smoking after PCI was associated with the 1-year risk of MACCE (P = 0.001, HR = 2.060, 95% CI 1.346-3.151), while OMT (P = 0.001, HR = 0.486, 95% CI 0.312-0.756) was an independent protective factor against postoperative MACCEs. CONCLUSIONS: There was still a gap between OMT utilization after PCI and the recommendations in the evidence-based guidelines. Sociodemographic and clinical factors influence the application of OMT. The management of OMT and smoking cessation after PCI should be emphasized.

Investigation on Community-based Rehabilitation Resources in Shanghai, China / 中国康复理论与实践

Objective:To investigate the rehabilitation resources of community health centers in Shanghai. Methods:December, 2018, all 247 community health centers in 16 districts of Shanghai were investigated with Health Institution Questionnaires, including the number of rehabilitation personnel (physiatrician, physical therapists) and the number of rehabilitation beds, etc. Results:There were 152 physiatrician and 597 physical therapists in community health centers in Shanghai. The numbers of physiatrician and physical therapists per 1000 registered population were 0.01 and 0.04, and were 0.03 and 0.12 for per 1000 registered elderly population. There were 17 484 beds in community health centers, in which the rehabilitation beds were 1425, accounting for 8.15%. Besides, the numbers of rehabilitation beds per 1000 registered population and registered elderly population in Shanghai were 0.10 and 0.30. Conclusion:The development of community-based rehabilitation in Shanghai is unbalanced. There is lack of community-based rehabilitation resources, the supply of service is insufficient, and there is gap between supply and demand. It is suggested to strengthen the support to community-based rehabilitation, and improve the supply of community-based rehabilitation resources.

Discussions on medical quality monitoring auxiliary system based on clinical big data / 中华医院管理杂志

With the development of big data, the Internet and information technology, artificial intelligence is gradually being applied to the field of hospital management. The authors used advanced artificial intelligence technology to conduct structured collection and monitor the hospital′s current medical quality data, identifying key points and key events affecting medical quality and safety from the link, and providing medical personnel′s behavior with pre-warning, process monitoring and post-evaluation to improve hospital medical quality management.

Serum uric acid and risk of incident diabetes in middle-aged and elderly Chinese adults: prospective cohort study / 医学前沿

The association between serum uric acid and the risk of incident diabetes in Chinese adults remains unknown. This study aimed to investigate this association in a community-dwelling population aged ≥ 40 years in Shanghai, China. Oral glucose tole3rance test was conducted during baseline and follow-up visits. Relative risk regression was utilized to examine the associations between baseline gender-specific serum uric acid levels and incident diabetes risk. A total of 613 (10.3%) incident diabetes cases were identified during the follow-up visit after 4.5 years. Fasting plasma glucose, postload glucose, and glycated hemoglobin A1c during the follow-up visit progressively increased across the sex-specific quartiles of serum uric acid (all Ps < 0.05). The incidence rate of diabetes increased across the quartiles of serum uric acid (7.43%, 8.77%, 11.47%, and 13.43%). Multivariate adjusted regression analysis revealed that individuals in the highest quartile had 1.36-fold increased risk of diabetes compared with those in the lowest quartile of serum uric acid (odds ratio (95% confidence interval) = 1.36 (1.06-1.73)). Stratified analysis indicated that the association was only observed in women. Accordingly, serum uric acid was associated with the increased risk of incident diabetes among middle-aged and elderly Chinese women.

Discussions on medical quality monitoring auxiliary system based on clinical big data / 中华医院管理杂志

With the development of big data, the Internet and information technology, artificial intelligence is gradually being applied to the field of hospital management. The authors used advanced artificial intelligence technology to conduct structured collection and monitor the hospital′s current medical quality data, identifying key points and key events affecting medical quality and safety from the link, and providing medical personnel′s behavior with pre-warning, process monitoring and post-evaluation to improve hospital medical quality management.

Single-cell RNA sequencing reveals distinct gene expression patterns in glucose metabolism of human preimplantation embryos.

Precise regulation of glucose metabolism-related genes is essential for early embryonic development. Although previous research has yielded detailed information on the biochemical processes, little is yet known of the dynamic gene expression profiles in glucose metabolism of preimplantation embryos at a single-cell resolution. In the present study, we performed integrated analysis of single-cell RNA sequencing (scRNA-seq) data of human preimplantation embryos that had been cultured in sequential medium. Different cells in the same embryo have similar gene expression patterns in glucose metabolism. During the switch from the cleavage to morula stage, the expression of glycolysis-related genes, such as glucose transporter genes (solute carrier family 2 (facilitated glucose transporter), member 1 (SLC2A1) and solute carrier family 2 (facilitated glucose transporter), member 3 (SLC2A3) and genes encoding hexokinase, phosphofructokinase, pyruvate kinase and lactate dehydrogenase, is increased. The genes involved in the pentose phosphate pathway are highly expressed at the cleavage stage, generating the reducing power to balance oxidative stress derived from biosynthesis. Expression of the genes involved in the biosynthesis of glycerophospholipids is increased after the morula stage. Nevertheless, the expression of tricarboxylic acid-related genes remains relatively unchanged during the preimplantation stages. In conclusion, we discovered that the gene expression profiles are dynamic according to glucose utilisation in the embryos at different stages, which contributes to our understanding of regulatory mechanisms of glucose metabolism-related genes in human preimplantation embryos.

Association of serum alanine aminotransferase with the risk of cardiovascular disease in middle-aged and elderly Chinese / 中华内分泌代谢杂志

Objective To investigate the association between levels of serum alanine aminotransferase (ALT) and the risks of cardiovascular disease in Chinese. Methods A survey of 10 375 subjects aged 40 or older in Jiading District of Shanghai was performed using cluster sampling. All the subjects were recruited to undergo questionnaire interview, anthropometric measurements, and fasting blood sampling. A total of 8 877 participants were included in the final analyses, including 5 664 females and 3 213 males. The mean age of individuals was ( 58.68 ± 9.22)yearsinmenand(57.65±8.93)yearsinwomen(P＜0.01).10-yearriskforafirsthardatherosclerotic cardiovascular diseases (ASCVD) event was calculated. Results Increased ALT levels were associated with more unfavorable cardiovascular risk profiles and 10-year risk for ASCVD. Increased ALT levels were associated with the prevalence of diabetes mellitus in female participants, while in male participants the prevalence of diabetes mellitus appeared as a U-distribution. The prevalence of hypertension and hyperlipidemia were 66.04%, 52.74%and 64.49%, 47.63% respectively. Increased serum ALT was associated with higher prevalence of 10-year risk for ASCVD. As compared with participants in the first ALT quartile, the risks of 10-year risk for ASCVD were increased by 148%(OR＝2.48, 95%CI 1.78-3.45) and 139%(OR＝2.39, 95%CI 1.78-3.19), respectively in male and female participants. As compared with participants in the first ALT quartile, higher prevalence of 10-year risk for ASCVD were increased by 96%(OR＝1.96, 95%CI 1.30-2.95), while there was no significantly statistical difference in men. Conclusion A high-normal serum ALT level was significantly associated with an increased risk of the cardiovascular disease in middle-aged and elderly Chinese.

Serum Uric Acid is Associated with the Predicted Risk of Prevalent Cardiovascular Disease in a Community-dwelling Population without Diabetes / 生物医学与环境科学（英文）

OBJECTIVE@#To examine the association between serum uric acid levels and cardiovascular disease risk among individuals without diabetes.@*METHODS@#We investigated the association between serum uric acid levels and the risk of prevalent cardiometabolic diseases, 10-year Framingham risk for coronary heart disease, and 10-year risk for atherosclerotic cardiovascular diseases (ASCVD) among 8,252 participants aged ⪖ 40 years without diabetes from Jiading district, Shanghai, China.@*RESULTS@#Body mass index, waist circumference, blood glucose, glycated hemoglobin, blood pressure, and serum lipids increased progressively across the sex-specific quartiles of uric acid (all P trend < 0.05). Compared with individuals in the lowest quartile, those in the higher quartiles had a significantly higher prevalence of obesity, hypertension, and dyslipidemia (all P trend < 0.05). A fully adjusted logistic regression analysis revealed that individuals in the highest quartile had an increased risk of predicted cardiovascular disease compared with those in the lowest quartile of uric acid. The multivariate adjusted odds ratios (ORs) [95% confidence intervals (CIs)] for the highest quartiles for high Framingham risk were 3.00 (2.00-4.50) in men and 2.95 (1.08-8.43) in women. The multivariate adjusted ORs (95% CIs) for the highest quartile for high ASCVD risk were 1.93 (1.17-3.17) in men and 4.53 (2.57-7.98) in women.@*CONCLUSION@#Serum uric acid level is associated with an increased risk of prevalent obesity, hypertension, dyslipidemia, 10-year Framingham risk for coronary heart disease, and 10-year risk for ASCVD among Chinese adults without diabetes.

Activity, Translocation, and Persistence of Isopyrazam for Controlling Cucumber Powdery Mildew.

A cotyledon bioassay was conducted to assess the activity of isopyrazam against Podosphaera xanthii (Castagne) U. Braun & N. Shishkoff, causal agent of cucumber powdery mildew. Results showed that isopyrazam has protective and curative activity against P. xanthii, with EC50 values of 0.04 and 0.05 mg liter-1, respectively. These activities are higher than those for hexaconazole, difenoconazole, pyraclostrobin, kresoxim-methyl, and azoxystrobin, fungicides currently used against cucumber powdery mildew. Isopyrazam at 0.5 mg liter-1 damaged conidiophores. Results of inoculation tests in greenhouse pots indicate that isopyrazam demonstrates a level of systemic movement in cucumber plants, especially regarding translaminar and transverse translocation. Efficacy following translaminar and transverse translocations on cotyledons and leaves treated with 60 mg liter-1 was 94.40% and 88.96%, and 95.26% and 82.83%, respectively. In addition, isopyrazam at 60 mg liter-1 exhibited a long duration of efficacy against cucumber powdery mildew, almost 2 to 3 weeks longer than that of triazoles and strobilurins. Similar trends in residual durations were observed during 2014 and 2015 greenhouse trials. Isopyrazam at 30 and 60 a.i. g ha-1 provided efficacy ranging from 83.27 to 90.83% 20 days following treatment. In conclusion, isopyrazam has translaminar and transverse translocation in cucumber leaves, and long duration of activity against cucumber powdery mildew.

Application of Balint special group training in the training of humanistic care for junior nurses / 现代临床护理

Objective To explore the effect of Balint group training on the humanistic caring ability of junior nurses. Methods About 96 junior nurses from the department of oncology were randomly assigned to an intervention group and a control group equally.Balint group training was given to the intervention group every 2 weeks in a year.The control group completed the humanistic care training according to the regular procedure in the department of the hospital.At the beginning of the study and at the end of the study,the nursing staff from the two groups and the patients under their continuous nursing care for more than 3 days were surveyed by the care efficiency scale,nursing care behavior scale and patient care perception questionnaire.Results Before the intervention,there was no significant difference between the groups in the care performance and behavior of nursing staff and the patients'care perception (P>0.05).After the intervention there was significant difference in the care performance and behavior of nursing staff and the patients' care perception (P<0.05). Conclusions Balint group training can improve the caring performance of junior nurses.Their ability to express care and establish the caring nurse-patient relationship can be improved by this group training.They become more voluntary to integrate caring behavior into the daily care and their caring behaviors can be more likely to be felt and recognize by the patients.

Association between obesity and chronic kidney disease among a middle-aged and elderly Chinese community population / 上海交通大学学报（医学版）

Objective·To investigate the relationship between obesity and chronic kidney disease (CKD) in a community-based study among a middle-aged and elderly Chinese population. Methods·A survey of 10375 inhabitants aged 40 years or older in Jiading District of Shanghai was performed using cluster sampling. All the subjects were recruited to undergo questionnaire interview, anthropometric measurements, and biochemical measurements. Blood and urine samples were collected to measure biochemical features, including plasma glucose, lipid profiles, liver and renal function, as well as urinary albumin and creatinine. Obesity status was diagnosed according to the World Health Organization (WHO) criteria. According to body mass index (BMI) levels, the subjects were divided into normal weight group (BMI<25 kg/m2), overweight group (25 kg/m2 ≤ BMI<30 kg/m2) and obesity group (BMI ≥ 30 kg/m2). The estimated glomerular filtration rate (eGFR) was calculated based on American Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) equation. Logistic regression analysis was used to analyze the risk of CKD among people with different BMI levels. Results·Increased BMI levels were associated with more unfavorable metabolic profiles. After a variety of factors were adjusted,each 1 kg/m2 increment of BMI was associated with a 9% higher risk of prevalent CKD, and the odds ratio (OR) was 1.09 (95% CI:1.07-1.12). Results from multivariate Logistic regression analysis showed that in the total population, compared with individuals in the normal weight group, those in the overweight and obesity groups had 51% (OR=1.51, 95% CI: 1.27-1.78) and 181% (OR=2.81, 95% CI: 2.20-3.61) higher risk of prevalent CKD. Conclusion·In the middle-aged and elderly community population in China, overweight and obesity are associated with an increased risk of prevalent CKD.

Association between obesity and chronic kidney disease among a middle-aged and elderly Chinese community population / 上海交通大学学报（医学版）

Objective·To investigate the relationship between obesity and chronic kidney disease (CKD) in a community-based study among a middle-aged and elderly Chinese population. Methods·A survey of 10375 inhabitants aged 40 years or older in Jiading District of Shanghai was performed using cluster sampling. All the subjects were recruited to undergo questionnaire interview, anthropometric measurements, and biochemical measurements. Blood and urine samples were collected to measure biochemical features, including plasma glucose, lipid profiles, liver and renal function, as well as urinary albumin and creatinine. Obesity status was diagnosed according to the World Health Organization (WHO) criteria. According to body mass index (BMI) levels, the subjects were divided into normal weight group (BMI<25 kg/m2), overweight group (25 kg/m2 ≤ BMI<30 kg/m2) and obesity group (BMI ≥ 30 kg/m2). The estimated glomerular filtration rate (eGFR) was calculated based on American Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) equation. Logistic regression analysis was used to analyze the risk of CKD among people with different BMI levels. Results·Increased BMI levels were associated with more unfavorable metabolic profiles. After a variety of factors were adjusted,each 1 kg/m2 increment of BMI was associated with a 9% higher risk of prevalent CKD, and the odds ratio (OR) was 1.09 (95% CI:1.07-1.12). Results from multivariate Logistic regression analysis showed that in the total population, compared with individuals in the normal weight group, those in the overweight and obesity groups had 51% (OR=1.51, 95% CI: 1.27-1.78) and 181% (OR=2.81, 95% CI: 2.20-3.61) higher risk of prevalent CKD. Conclusion·In the middle-aged and elderly community population in China, overweight and obesity are associated with an increased risk of prevalent CKD.

Magmatic record of India-Asia collision.

New geochronological and geochemical data on magmatic activity from the India-Asia collision zone enables recognition of a distinct magmatic flare-up event that we ascribe to slab breakoff. This tie-point in the collisional record can be used to back-date to the time of initial impingement of the Indian continent with the Asian margin. Continental arc magmatism in southern Tibet during 80-40 Ma migrated from south to north and then back to south with significant mantle input at 70-43 Ma. A pronounced flare up in magmatic intensity (including ignimbrite and mafic rock) at ca. 52-51 Ma corresponds to a sudden decrease in the India-Asia convergence rate. Geological and geochemical data are consistent with mantle input controlled by slab rollback from ca. 70 Ma and slab breakoff at ca. 53 Ma. We propose that the slowdown of the Indian plate at ca. 51 Ma is largely the consequence of slab breakoff of the subducting Neo-Tethyan oceanic lithosphere, rather than the onset of the India-Asia collision as traditionally interpreted, implying that the initial India-Asia collision commenced earlier, likely at ca. 55 Ma.

Enzymatic cyclization of peptides using immobilized sortase A / 药学学报

Peptide cyclization, a pivotal approach to modifying linear precursors of proteins and pepticles, has been used to enhance their biological activities and serum stabilities. Recently, sortase A (SrtA) from Staphyloccus aureus becomes a promising new technology for efficiently incorporating site specific modifications into proteins, conjugating the cell surface and cyclizing the linear peptides. In this study, we constructed two recombinant expression systems, one with chitin binding domain and the other with six-histidine tag and chitin binding domain on the N-terminal of SrtA, separately. The results of enzymatic kinetics indicate that the two recombinant tags do not impair the transpeptidase activity of SrtA compared with the standard reaction reported under the same reaction condition. The two synthesized peptides with N-ternimal three glycines and C-terminal penta-amino acid motif, LPETG, were cyclized using immobilized and recycled SrtA. The SrtA-based cyclization promises to represent a simple method for easy and efficient enzymatic synthesis of large cyclic peptides.

The deployment of routing protocols in distributed control plane of SDN.

Software defined network (SDN) provides a programmable network through decoupling the data plane, control plane, and application plane from the original closed system, thus revolutionizing the existing network architecture to improve the performance and scalability. In this paper, we learned about the distributed characteristics of Kandoo architecture and, meanwhile, improved and optimized Kandoo's two levels of controllers based on ideological inspiration of RCP (routing control platform). Finally, we analyzed the deployment strategies of BGP and OSPF protocol in a distributed control plane of SDN. The simulation results show that our deployment strategies are superior to the traditional routing strategies.