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In recent years, laparoscopic surgery and robotic surgery have been widely used, and various intraoperative image navigation systems have also developed rapidly. However, the liver itself has a complex vessel and duct system, which increase the difficulty of liver surgery. The augmented reality image navigation system combines the three-dimensional reconstructed image of the liver with the real liver anatomy, which presents the specific relationship between the tumor location and the surrounding vessels for the surgeon. Compared with other intraoperative image navigation methods, augmented reality has its unique advantages. This paper provides an overview of current advances in registration technology in augmented reality image navigation system, and focuses on its applications in liver surgery, including laparoscopic surgery and robotic surgery. Finally, the technological problems and difficulties still faced at present are summarized, and future directions worth studying in this field are proposed.
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Objective: To investigate the long-term efficacy and safety of left cardiac sympathetic denervation(LCSD) for long QT syndrome(LQTS) patients with either recurrence on drug therapy intolerance/refusal. Methods: This study was a retrospective cohort study. The cases selected from 193 patients with LQTS who were enrolled in the Chinese Channelopathy Registry Study from November 1999 to November 2012. This study selected 28 LQTS patients with either recurrence on drug therapy intolerance/refusal and underwent LCSD surgery in the Peking University People's Hospital or Beijing Tongren Hospital. The patients were allocated into 3 groups: high-risk group(n=13, baseline QTc ≥550 ms or symptomatic in the first year of life or highly malignant genetics); intermediate-risk group(n=10, 500 ms≤baseline QTc<550 ms, symptomatic after the first year and without highly malignant genetics); low-risk group(n=5, baseline QTc<500 ms, symptomatic after the first year and without highly malignant genetics). LCSD was performed with the traditional supraclavicular approach or video assisted thoracoscopic surgery (VATS). Patients were regularly followed up until 20 years after the surgery. Data were collected before and 1 year after surgery and at the last follow-up. Patients' electrocardiograph(ECG), cardiac events and surgery-related complications were recorded. Kaplan-Meier survival analysis was used to determine the cardiac event-free survival based on different risk stratification and genotypes. Results: A total of 28 LQTS patients, aged 20.5 (15.0, 37.5) and underwent LCSD surgery, were enrolled in this study, including 23(82.1%) women. There were 11(39.3%) patients treated with traditional approach while 17(60.7%) with VATS-LCSD. There were 19(67.9%) patients had positive genetic test results, including 4 LQT1, 12 LQT2, 1 LQT1/LQT2 mixed type, and 2 Jervell-Lange-Nielsen (JLN) syndrome. The median follow-up period was 189.3(138.7, 204.9) months. The dropout rate was 10.7%(3/28) while 3 patients in the intermediate-risk group were lost to follow-up. Horner syndrome occurred in 1 patient (in the high-risk group). Sudden cardiac deaths were observed in 3 (12.0%) patients (all in the high-risk group), and 12 patients (48.0%) had syncope recurrences (2 in low-risk group, 3 in intermediate-risk group and 7 in high-risk group). A significant reduction in the mean yearly episodes of cardiac events was observed, from (3.5±3.3) before LCSD to(0.2±0.1) at one year after LCSD and (0.5±0.8) at last follow up(P<0.001). The mean QTc was shortened from (545.7±51.2)ms before the surgery to (489.0±40.1)ms at the last follow-up (P<0.001). Among the 20 patients with basic QTc ≥500 ms and completing the follow-up, the QTc intervals of 11(55.0%) patients were shortened to below 500 ms. The event free survival rates for any cardiac events after LCSD decreased sequentially in the low-, intermediate- and high-risk groups, and the difference was statistically significant (χ²=7.24, log-rank P=0.026). No difference was found in the event free survival rates among LQT1, LQT2 and undefined gene patients (χ²=5.20, log-rank P>0.05). Conclusions: LCSD surgery can reduce the incidence of cardiac events and shorten the QTc interval in patients with LQTS after the long-term follow-up. LCSD surgery is effective and safe for patients with LQTS ineffective or intolerant to drug therapy. However, high-risk patients are still at a high risk of sudden death after surgery and should be actively monitored and protected by combined therapies.
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Síndrome do QT Longo , Eletrocardiografia , Feminino , Coração , Humanos , Masculino , Estudos Retrospectivos , Simpatectomia/efeitos adversos , Simpatectomia/métodosRESUMO
Objective: To establish an animal model of trichloroethylene (TCE) -induced liver cancer following chronic exposure and to understand the changes in SET expression and histone acetylation, potentially serving as a molecular mechanism for TCE-induced hepatocarcinogenesis. Methods: B6C3 mice at 6 weeks were treated with TCE at a series of doses (500, 1000 and 2000 mg/kg) by gastric gavage, with corn oil used as the negative control and carbon tetrachloride (CCl(4)) as the positive control. The serum and liver were sampled for the determination of biochemical indexes and pathological examination after 56 weeks of chemical exposure. Western blot was used to determine the levels of SET, H2AK9ac and HDAC1 expression. Results: The overall survival rate of the mice in various groups was 90.4% (141/156) , with no statistical difference between groups (P>0.05) . Compared with the negative control, the organ coefficient for the liver in the high dose TCE group and the positive control group were significantly increased (P<0.05) . The levels of ALT, AST, LDH and BUN in the all the three TCE groups and the positive control were significantly higher than those in the negative control (P<0.01) . CREA levels in the 1000 and 2000 mg/kg TCE groups were significantly higher than those in the negative control (P<0.05) . Statistical increases in the incidence of hepatocellular carcinoma and the activities of ALT and AST in various doses of TCE-exposed mice as compared with the control were observed (P<0.01) , in a dose-dependent manner. In the 1000 and 2000 mg/kg of TCE treated mice, levels of SET and H2AK9ac were increased (P<0.05) , while HDAC1 was decreased (P<0.05) , Compared to the tissue adjacent to liver cancer, in the 1000 and 2000 mg/kg TCE groups, the levels of SET were increased (P<0.05) , while HDAC1 was decreased (P<0.05) , and H2AK9ac increased in the 2000 mg/kg group. Conclusion: The hepatocellular carcinoma mouse model induced by chronic exposure to trichloroethylene was successfully established, with enhanced SET protein expression and H2AK9ac in the hepatic tissue.
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Carcinoma Hepatocelular , Neoplasias Hepáticas , Tricloroetileno , Acetilação , Animais , Carcinoma Hepatocelular/metabolismo , Histonas/metabolismo , Fígado/metabolismo , Neoplasias Hepáticas/metabolismo , Camundongos , Tricloroetileno/toxicidadeRESUMO
Objective: To investigate the application value of reactive oxygen species (ROS) and adiponectin (ADPN) in the judgment of liver inflammation in chronic hepatitis B virus infection combined with nonalcoholic fatty liver disease (NAFLD). Methods: A total of 159 cases with NAFLD (21 cases), chronic hepatitis B virus infection (57 cases), and chronic hepatitis B virus infection combined with NAFLD (81 cases) were collected between June 2016 to December 2018, and the visited patients diagnosis were confirmed by histopathological examination of the liver. ROS and ADPN level retained in serum was determined by enzyme-linked immunosorbent assay. Histopathological examination of liver tissue was used as the gold standard to discuss the diagnostic value of the serum in patients with chronic hepatitis B virus infection combined with NAFLD for the occurrence of nonalcoholic steatohepatitis. One-way analysis of variance was used for the comparison among multiple groups, and LSD-t test was used for pairwise comparison between groups. Measurement data for non-normal distributions were expressed as M (P25, P75). Comparisons between groups were performed using the Mann-Whitney U or Kruskal-Wallis H test. Chi-square test was used to compare the count data between groups. Correlation analysis was performed using Spearman correlation analysis. Histopathological grouping of liver tissue was used as the gold standard, and the area under the receiver operating characteristic curve was used to evaluate the diagnostic efficacy of the regression formula. Results: (1) In patients with chronic hepatitis B virus infection combined with NAFLD, the levels of ROS in the non-hepatic steatosis group and the mild hepatic steatosis group were significantly lower than those in the moderate and severe hepatic steatosis group, while the ADPN level in the non-hepatic steatosis group was significantly higher than liver steatosis group, P < 0.05. (2) The results of correlation analysis showed that ROS was significantly correlated with NAS score, change in the degree of fatty liver and lobular inflammation (all P < 0.05).There was a significant negative correlation between ADPN and the change in the degree of fatty liver (P < 0.05). (3) Logistic regression analysis results showed that the diagnostic formula for chronic hepatitis B virus infection combined with nonalcoholic steatohepatitis was 0.02 × controlled attenuation index + 0.584 × white blood cells/10(9) + 0.587 × ROS-10.982. The area under receiver operating characteristic curve of the subject was = 0.896. The sensitivity, specificity, positive and negative predictive value were 97.1%, 71.2%, 64.2%, and 97.9%. Conclusion: ADPN and ROS have certain reference value in differentiating the change in the degree of fatty liver and inflammation in chronic hepatitis B virus infection combined with NAFLD and the diagnostic formula has higher application value in the diagnosis and exclusion of chronic hepatitis B virus infection combined with nonalcoholic steatohepatitis.
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Adiponectina/sangue , Hepatite B Crônica/sangue , Hepatopatia Gordurosa não Alcoólica/sangue , Hepatopatia Gordurosa não Alcoólica/virologia , Espécies Reativas de Oxigênio/sangue , Biópsia , Vírus da Hepatite B , Hepatite B Crônica/complicações , Humanos , FígadoRESUMO
Objective: To report a case of acute glufosinate-ammonium poisoning cause respiratory cardiac arrest and grass amine poisoning cases of successful rescue. Methods: The clinical data of a case of acute glufosinate-ammonium poisoning admitted to a third-class a hospital in April 2018 were analyzed and summarized. Results: The patient was poisoned by oral administration of a large amount of glufosinate-ammonium. Respiratory and cardiac arrest occurred during treatment and resuscitation was successful Later, the nervous system showed impaired function, The patients were treated with complete gastrointestinal cleansing, hemoperfusion, and the protection of important organs. Conclusion: For a large number of patients with oral glufosinate-ammonium poisoning, we should pay close attention to the damage of nervous system while taking active and conventional detoxification treatment.
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Aminobutiratos/intoxicação , Parada Cardíaca/induzido quimicamente , Herbicidas/intoxicação , Parada Cardíaca/terapia , Hemoperfusão , Humanos , Desintoxicação por SorçãoRESUMO
Objective: To investigate alteration of proteins profile in malignant transformation bronchial epithelial cells(16HBE-T) induced by hexavalent chromium[(Cr(VI))] and analyze the expression level of SET protein, then to provide some new insights for the carcinogenesis mechanism of Cr(VI). Methods: Total protein was extracted from 16HBE cells and was alkylated and desalinated before digested into peptides. The products were labeled with Tandem Mass Tag (TMT) and identified using LC-ESI-MS/MS. Results: A total of 3 517 proteins were found, expression differences greater than 1.5 or less 0.67 times were to found have 185 and 201 proteins, respectively. Gene enrichment analysis revealed that differential proteins were mainly involved in autophagy, DNA damage repair, RNA processing and other biological processes. Western blot results showed the expression level of SET was significantly increased while downregulated in histone H3K18/27 acetylation and p53 protein. Conclusion: Proteins involved in multiple biological processes altered in 16HBE-T cells and regulation mode of SET inhibiting histone H3K18/27 acetylation regulating transcriptional activity of p53 may paly an important role in Cr(VI)-association carcinogenesis.
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Transformação Celular Neoplásica , Cromo , Proteômica , Brônquios , Transformação Celular Neoplásica/induzido quimicamente , Transformação Celular Neoplásica/genética , Cromo/toxicidade , Reparo do DNA , Proteínas de Ligação a DNA , Genes p53/efeitos dos fármacos , Chaperonas de Histonas/metabolismo , Espectrometria de Massas em Tandem , Fatores de Transcrição/metabolismoRESUMO
Objective: To explore the trichloroethylene-induced alteration of methylation on the promoter region of SET and related mechanisms in hepatic L-02 cells. Methods: L-02 cells were treated with different concentrations of TCE(0 mmol/L, 1 mmol/L, 2 mmol/L, 4 mmol/L, 8 mmol/L) for 24 h. The genomic DNA were then extracted and modified by bisulfite sodium. The DNA methylation was then analyzed using bisulfite sequencing PCR (BSP). Results: The overall methylation on promoter region of SET was decreased along with the increased concentrations of TCE in hepatic L-02 cells. Moreover, 73 CpG islands were found abnormally altered, among which 9 were predicted in transcriptional factor binding regions. Conclusion: The decreased levels of CpG islands in the transcriptional factor binding region may contribute to the elevation of SET in TCE-induced hepatotoxicity.
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Metilação de DNA/efeitos dos fármacos , Hepatócitos , Regiões Promotoras Genéticas/genética , Tricloroetileno/toxicidade , Linhagem Celular , Ilhas de CpGRESUMO
INTRODUCTION: Haemophilic arthritis is the most universal clinical appearance of haemophilia. Treatment of this disease has become an important and difficult issue worldwide until recently. OBJECTIVE: To investigate the efficacy and safety of five in one therapy for graded treatment of haemophilic arthritis. METHODS: Haemophilic arthritis was classified into grades I-IV according to severity and the standards of De Palma and Cotler. Under no application of FVIII/FIX replacement therapy state, the effect of five in one therapy (intra-articular cavity drug injection, oral drug preparation, physiotherapy, and prevention of haemorrhage and infection evoked by puncture) was observed in 1527 affected joints of 750 cases of haemophilic arthritis. RESULTS: After 20 days treatment, all grade I and II, 94.98% of grade III and 56.16% of grade IV affected joints were completely relieved; 5.02% of grade III and 41.47% of grade IV affected joints were basically relieved; and 2.38% of grade IV were partially relieved. This resulted in short-term complete and basic relief of 98.56% (1505/1527) of all affected joints. After follow-up of 1-6 years, 86.97% of the affected joints were completely relieved, without any adverse reaction or complication. CONCLUSION: The results suggest that five in one therapy is safe and effective for treatment of haemophilic arthritis, and provides a convenient, cost-effective way of preventing and treating deformity caused by haemophilic arthritis.
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This study was designed to evaluate the effect of miRNA acting in regulating multi-directional differentiation ability of mesenchymal stem cell in treatment of osteoporosis (OP), with the aim of finding a new idea and approach for clinical treatment of OP. Estrogen deficiency-induced OP mice model was established by means of ovariectomy (OVX). Additionally, a sham group was set up for control. Bone Marrow Mesenchymal Stem Cells (BMMSCs) of OVX group (O/BMMSCs) and BMMSCs of sham group (S/BMMSCs) were separately cultured. Then surface markers of BMMSCs were detected. Multi-directional differentiation ability was identified in the two groups by giving cells targeted induced stimulation. It was found that the bone trabecula, bone density and bone volume fraction of distal femoral metaphysis in the OVX group were much lower than those of the sham group. Moreover, trabecular bone space in the OVX group became larger; O/BMMSCs and S/BMMSCs both had normal expression of surface markers as well as potentials of osteogenic and adipogenic differentiation; O/BMMSCs had a weaker osteogenic capability but a stronger adipogenic capability than S/BMMSCs. All the findings suggest that the regulatory effect of miRNA on multi-directional differentiation ability plays a vital role in the treatment of OP, and there is a close correlation between them; deficiency or functional defect of BMMSCs can result in the occurrence of OP.
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Células-Tronco Mesenquimais/citologia , MicroRNAs/fisiologia , Osteogênese , Osteoporose/terapia , Animais , Diferenciação Celular , Feminino , Camundongos , Camundongos Endogâmicos C57BLRESUMO
Objective: To investigate the differences and similarities between drug-induced liver injury (DILI) and autoimmune hepatitis (AIH) in serum biochemical parameters and liver pathology, and to provide some thoughts for clinical diagnosis and differentiation of these two diseases. Methods: A retrospective analysis was performed for the biochemical, immunological, autoantibody, and liver pathological data of 106 DILI patients and 63 AIH patients who were hospitalized, diagnosed, and treated in our hospital from January 2012 to October 2014. The patients' general data, biochemical parameters, immunological data, Ishak score, and qualitative changes in liver tissue were analyzed and compared. The Kruskal-Wallis test was used for comparison of nonparametric data between multiple groups, the Nemenyi test was used for comparison of nonparametric data between any two groups, the Wilcoxon rank sum test was used for comparison of Ishak scores, and the chi-square test was used for comparison of constituent ratio of categorical data. Results: There were significant differences between AIH group and DILI hepatocyte injury group/mixed-type DILI group in the following serum biochemical parameters: alanine aminotransferase (187.2 U/Lvs 1 326.5 U/L and 455.6,P< 0.05), aspartate aminotransferase (172.2 U/L vs 759.5 U/L and 349.5 U/L,P<0.05), alkaline phosphatase (209.3 U/L vs 157.3 U/L and 169.4 U/L,P< 0.05), gamma-glutamyl transferase (254.8 U/L vs 176.5 U/L and 170.5 U/L,P< 0.05), total bilirubin (37.2µmol/L vs 95.8µmol/L and 52.6µmol/L,P< 0.05), serum iron (18.9µmol/L vs 36.2µmol/L and 23.9µmol/L,P< 0.05), serum ferritin (122.5µmol/L vs 410.4µmol/L and 186.5µmol/L,P< 0.05), immunoglobulin G (18.4 g/L vs 12.6 g/L and 12.3 g/L,P< 0.05), and immunoglobulin M (1.8 g/L vs 1.3 g/L and 1.1 g/L,P< 0.05). There were also significant differences between AIH group and DILI hepatocyte injury group/mixed-type DILI group in the Ishak score for interface inflammation (2.2±0.8 vs 1.3±0.7 and 1.3±0.6,P< 0.05), Ishak score for portal inflammation (2.3±0.9 vs 1.5±0.7 and 1.4±0.8,P< 0.05), and fibrosis score (2.8±1.1 vs 1.5±0.7 and 1.3±0.7,P< 0.05). There were significant differences between AIH group and DILI hepatocyte injury group/mixed-type DILI group in the proportion of wax-like deposition (0 vs 29.2% and 34.5%, P <0.05) and proportion of iron deposition (11.1% vs 52.1% and 25.9%,P< 0.05). Conclusion: There are differences in biochemistry, immunology, and liver histology between DILI and AIH patients. AIH patients have more serious interface inflammation and portal inflammation and a higher fibrosis degree compared with DILI patients, while DILI patients have greater proportions of wax-like deposition and iron deposition compared with AIH patients.
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Doença Hepática Induzida por Substâncias e Drogas/diagnóstico , Hepatite Autoimune/diagnóstico , Fígado/patologia , Alanina Transaminase/sangue , Fosfatase Alcalina/sangue , Aspartato Aminotransferases/sangue , Autoanticorpos/sangue , Bilirrubina , Doença Hepática Induzida por Substâncias e Drogas/sangue , Doença Hepática Induzida por Substâncias e Drogas/patologia , Feminino , Hepatite Autoimune/patologia , Humanos , Masculino , Estudos Retrospectivos , gama-GlutamiltransferaseRESUMO
This study aimed to explore the relationship between genetic changes and high-altitude pulmonary edema (HAPE) susceptibility, and to screen for the key single nucleotide polymorphism (SNP) loci in the HAPE-susceptibility gene, by investigating the SNPs occurring in hypoxia-related genes in HAPE-susceptible and control (non-susceptible) populations. This research was conducted on Han recruits, who travelled to the Lhasa plateau (altitude, 3658 m). Ten loci located on ten genes extracted from the HAPE and healthy populations were amplified by polymerase chain reaction, and subsequently sequenced. The investigated genes included those coding for aldosterone synthase 2 (CYP11B2), angiotensin-converting enzyme (ACE), heat-shock protein 70 (HSP70), nuclear factor kappa B (NF-κB), surfactant protein A2 (SP-A2), plasminogen activator inhibitor-1 (PAI-1), nitric oxide synthetase (NOS), vascular endothelial growth factor (VEGF), prolyl hydroxylase (EGLN1), and zinc finger protein A20. The gene distribution of each SNP loci and its correlation with HAPE was analyzed. Statistical analyses of the genotype frequencies of the SNPs revealed significant differences in the ACE (rs4309), EGLN1 (rs480902), SP-A2 (rs1965708), HSP70 (rs1008438), PAI-1 (rs1799889), and NOS (rs199983) expressions between the HAPE and healthy control groups (P < 0.05); therefore, these SNP loci were believed to indicate HAPE susceptibility. HAPE is correlated with multiple- SNP loci. A correlation analysis between genetic polymorphism and HAPE susceptibility revealed that 6 hypoxia-related genes were key sites accounting for HAPE. These findings could help assess the risk of HAPE in populations expressing different genotypes, in order to reduce the occurrence of HAPE.
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Altitude , Predisposição Genética para Doença , Hipóxia/genética , Polimorfismo de Nucleotídeo Único/genética , Edema Pulmonar/genética , Doença Aguda , Alelos , Sequência de Bases , Análise Mutacional de DNA , Proteínas de Ligação a DNA/genética , Frequência do Gene/genética , Loci Gênicos , Proteínas de Choque Térmico HSP70/genética , Heterozigoto , Homozigoto , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Dados de Sequência Molecular , NF-kappa B/genética , Óxido Nítrico Sintase/genética , Proteínas Nucleares/genética , Peptidil Dipeptidase A/genética , Inibidor 1 de Ativador de Plasminogênio/genética , Prolil Hidroxilases/genética , Regiões Promotoras Genéticas/genética , Proteína A Associada a Surfactante Pulmonar/genética , Proteína 3 Induzida por Fator de Necrose Tumoral alfa , Fator A de Crescimento do Endotélio Vascular/genéticaRESUMO
We examined the expression of myosin heavy chain (MyHC) isoforms and forkhead box transcription factor O1 (FoxO1) in porcine soleus and extensor digitorum longus (EDL) muscles to clarify the correlation of FoxO1 and the relative abundance of transcripts of MyHC isoforms. Soleus muscle was found to be redder than EDL muscles in pigs, and immunohistochemical fast MyHC staining showed more oxidative type I fibers compared to EDL. qRT-PCR quantification of MyHC isoforms I, IIa, IIx, and IIb showed that expression of MyHC I and MyHC IIa mRNAs was much higher, whereas expression of MyHC IIx and MyHC IIb mRNAs was much lower in porcine soleus muscle compared to EDL muscle. Expression of FoxO1 mRNA and p-FoxO1 protein was significantly more abundant in porcine soleus muscle compared to EDL muscle. The expression of phosphorylated FoxO1 (p-FoxO1) was positively correlated with the expression of MyHC I (R = 0.9747, P < 0.01) and negatively correlated with the expression of MyHC IIx (R = -0.9963, P < 0.01) and MyHC IIb (R = -0.9834, P < 0.01). Taken together, these results suggested that FoxO1 may play a pivotal role in the determination of muscle fiber type.
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Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Músculo Esquelético/metabolismo , Cadeias Pesadas de Miosina/genética , Suínos/genética , Animais , Masculino , Músculo Esquelético/citologia , Cadeias Pesadas de Miosina/metabolismo , Especificidade de Órgãos , Fosforilação , Isoformas de Proteínas/metabolismo , Suínos/metabolismoRESUMO
To better understand the function of the myostatin gene and its promoter region in bovine, we amplified and sequenced the myostatin gene and promoter from the blood of Qinchuan and Red Angus cattle by using polymerase chain reaction. The sequences of Qinchuan and Red Angus cattle were compared with those of other cattle breeds available in GenBank. Exon splice sites were confirmed by mRNA sequencing. Compared to the published sequence (GenBank accession No. AF320998), 69 single nucleotide polymorphisms (SNPs) were identified in the Qinchuan myostatin gene, only one of which was an insertion mutation in Qinchuan cattle. There was a 16-bp insertion in the first 705-bp intron in 3 Qinchuan cattle. A total of 7 SNPs were identified in exon 3, in which the mutation occurred in the third base of the codon and was synonymous. On comparing the Qinchuan myostatin gene sequence to that of Red Angus cattle, a total of 50 SNPs were identified in the first and third exons. In addition, there were 18 SNPs identified in the Qinchuan cattle promoter region compared with those of other cattle compared to the Red Angus cattle myostatin promoter region. breeds (GenBank accession No. AF348479), but only 14 SNPs when compared to the Red Angus cattle myostatin promoter region.
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Miostatina/genética , Polimorfismo de Nucleotídeo Único/genética , Regiões Promotoras Genéticas , Alelos , Animais , Cruzamento , Bovinos , Éxons , Íntrons , Dados de Sequência Molecular , RNA Mensageiro/genéticaRESUMO
The energy spread (ΔE) of an ion source is an important parameter in the production of a finely focused primary ion beam applied in secondary ion mass spectrometry (SIMS). A variable-focusing retarding field energy analyzer (RFEA) has been developed and tested with an Ar+ beam and an oxygen ion beam extracted from a 2.45 GHz microwave ion source, which is developed as a candidate ion source for SIMS applications. The simulation results show that the relative resolution ΔE/E of the designed RFEA reaches 7 × 10-5. The experimental results indicate that a focusing electrode can improve the ΔE measurement results, which is consistent with the simulation results. The ion energy distributions of the Ar+ beam and oxygen ion beam are of Gaussian distribution with the value of ΔE of 3.3 and 2.9 eV, respectively. These results indicate that the designed RFEA is reliable for measuring the ion beam energy spread. The developed RFEA is also used to study the plasma behavior in different settings, which reveals that plasma stability is critical to making a low energy spread ion beam. This paper will present the simulation, design, and test of the variable-focusing RFEA. Preliminary ion beam quality studies with this instrument will also be discussed.
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A high brightness and low energy spread (∆E) ion source is essential to the production of a high-quality primary ion beam applied in secondary ion mass spectrometry (SIMS). A compact 13.56 MHz radio-frequency (RF) ion source with an external planar spiral antenna has been developed as a candidate ion source for the production of negative oxygen ion beams for SIMS application. This ion source is designed with a three-and-a-half-turn water-cooled planar antenna for RF power coupling, a multi-cusp magnetic field for effective plasma confinement, and a three-electrode extraction system. The experimental results show that more than 50 µA negative oxygen ion beams have been extracted, which consist of 56% O-, 25% O2-, and 19% O3-. The ion energy distribution of the negative oxygen ion beam exhibits a Gaussian distribution with a minimum ∆E of 6.3 eV. The brightness of the O- beam is estimated to be 82.4 A m-2 Sr-1 V-1. The simulation, design, and experimental study results of this RF ion source will be presented in this paper.
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Space charge effect of intense ion beam has critical influence on separation efficiency in the electromagnetic isotope separator. In this paper, a ribbon beam extraction system with slit electrodes for an electromagnetic isotope separator was designed and studied. The extracted beam currents were varied from 10 to 40 mA and the corresponding extracted beam energies were 40 keV and 100 keV respectively. The simulated output beam density distributions were used in the subsequent multi species particle transmission simulation with the space charge effect included. The separated isotope beam spot distributions at the focal plane were simulated under different space charge compensation factors and thus the optimum operation gas pressures in vacuum box were roughly estimated. For the case of high intensity and high power isotope beam collection, an isotope collector with a deceleration electrode was proposed to mitigate the effect of high power beam bombardment and the resultant temperature rising on the collector surface.