Associations between neutrophil-lymphocyte ratio and monocyte to high-density lipoprotein ratio with left atrial spontaneous echo contrast or thrombus in patients with non-valvular atrial fibrillation.

BACKGROUND: The importance of inflammation in thrombosis is increasingly appreciated. Neutrophil-lymphocyte ratio (NLR) and monocyte to high-density lipoprotein ratio (MHR) are important indicators of systemic inflammation. This study aimed to investigate the associations between NLR and MHR with left atrial appendage thrombus (LAAT) and spontaneous echo contrast (SEC) in patients with non-valvular atrial fibrillation. METHODS: This retrospective, cross-sectional study enrolled 569 consecutive patients with non-valvular atrial fibrillation. Multivariable logistic regression analysis was used to investigate independent risk factors of LAAT/SEC. Receiver operating characteristic (ROC) curves were used to evaluate the specificity and sensitivity of NLR and MHR in predicting LAAT/SEC. Subgroup and Pearson correlation analyses were used to assess the correlations between NLR and MHR with the CHA2DS2-VASc score. RESULTS: Multivariate logistic regression analysis showed that NLR (OR: 1.49; 95%CI: 1.173-1.892) and MHR (OR: 2.951; 95%CI: 1.045-8.336) were independent risk factors for LAAT/SEC. The area under the ROC curve of NLR (0.639) and MHR (0.626) was similar to that of the CHADS2 score (0.660) and CHA2DS2-VASc score (0.637). Subgroup and Pearson correlation analyses showed significant but very weak associations between NLR (r = 0.139, P < 0.05) and MHR (r = 0.095, P < 0.05) with the CHA2DS2-VASc score. CONCLUSION: Generally, NLR and MHR are independent risk factors for predicting LAAT/SEC in patients with non-valvular atrial fibrillation.

Hyperuricemia and Gout are Associated with the Risk of Atrial Fibrillation: An Updated Meta-Analysis.

Background: Although it has been suggested that hyperuricemia and gout are predictive of the future risk of atrial fibrillation, there is still a lack of epidemiological evidence. Objective: Through an updated systematic review and meta-analysis, we aimed to assess the association between hyperuricemia/gout and atrial fibrillation. Methods: We performed a systematic search of EMBASE, PubMed, and Web of Science from their establishment to September 2021 for all relevant studies of hyperuricemia or gout and atrial fibrillation. Meta-analysis was conducted using the random-effects method to calculate the overall relative risk (RR) and 95% confidence intervals (CI), and subgroup analyses were performed on data subsets by geographic location and study design. Result: A total of 12 studies were included in this study. The results from 8 studies showed that hyperuricemia was associated with an increased incidence of atrial fibrillation (RR: 1.83, 95% CI: 1.35-2.47), but significant association was only observed in studies in China (RR: 1.88, 95% CI: 1.31-2.71) and cross-sectional studies (RR: 2.35, 95% CI: 1.97-2.81) rather than studies in Japan (RR: 1.74, 95% CI: 0.71-4.23) and cohort studies (RR: 1.20, 95% CI: 0.99-1.46). The results from 4 studies showed that gout was also associated with an increased risk of AF (RR: 1.33, 95% CI: 1.04-1.71). Conclusions: Hyperuricemia and gout are associated with an increased incidence of atrial fibrillation.

Identification and application of T3SS translocation signal in Edwardsiella piscicida attenuated carrier as a bivalent vaccine.

Type III secretion system (T3SS)-dependent translocation has been used to deliver heterologous antigens by vaccine carriers into host cells. In this research, we identified the translocation signal of Edwardsiella piscicida T3SS effector EseG and constructed an antibiotic resistance-free balanced-lethal system as attenuated vaccine carrier to present antigens by T3SS. Edwardsiella piscicida LSE40 asd gene deletion mutant was constructed and complemented with pYA3342 harbouring the asd (aspartate ß-semialdehyde dehydrogenase) gene from Salmonella. Fusion proteins composed of EseG N-terminal 1-108 amino acids and the TEM1-ß-lactamase reporter were inserted in plasmid pYA3342. The fusion protein could secrete into the cell culture, translocate into HeLa cells, and localize in the membrane fraction. Then, the double gene deletion mutant LSE40ΔasdΔpurA was constructed as an attenuated vaccine carrier, and Aeromonas hydrophila GapA (glyceraldehyde-3-phosphate dehydrogenase) was fused with the translocation signal, instead of the TEM1-ß-lactamase reporter. The bivalent vaccine could protect blue gourami (Trichogaster trichopterus) against E. piscicida and A. hydrophila, with the relative per cent survival of 80.77% and 63.83%, respectively. These results indicated that EseG N-terminal 1-108 amino acid peptide was the translocation signal of E. piscicida T3SS, which could be used to construct bivalent vaccines based on an attenuated E. piscicida carrier.

A case of variant angina associated with syncope detected by an implantable loop recorder.

The implantable loop recorder (ILR) is a small device used to monitor the electrical activity of the heart by recording a single­lead bipolar electrocardiograph signal over a long period of time. The ILR is a valid diagnostic tool but has been vastly underused. In addition to arrhythmia, the ILR may be a useful tool for the detection of repolarization disorders in patients with myocardial ischemia.

Association of insulin resistance with polymorphic variants of Clock and Bmal1 genes: A case-control study.

Background: Little information is available in the literature for the correlation of insulin resistance (IR) and CLOCK gene polymorphism in Chinese population. This study aimed to investigate the relationship of HOMA-IR (homeostasis model assessment of insulin resistance) to polymorphic variants of Clock and Bmal1 genes in Chinese patients with essential hypertension.Methods: A total of 334 outpatients with essential hypertension (103 patients of HOMA-IR positive and 231 patients of HOMA-IR negative) were recruited to analyze Clock T3111C and Bmal1 A1420G genotypes with DNA sequencing approach.Results: Waist circumference, body mass index, glycated hemoglobin, total cholesterol, triglyceride, and plasminogen activator inhibitor-1 were significantly increased, while high-density lipoprotein cholesterol was significantly decreased in patients with HOMA-IR positive (P < .05-0.001 vs. patients with HOMA-IR negative). Twenty-four-hour ambulatory blood pressure monitoring showed that 24-h mean systolic blood pressure (SBP), especially nightime SBP, was higher in patients with HOMA-IR positive (P < .05 vs. patients with HOMA-IR negative). Notably, compared with the negative group, the distribution frequency of C allele of Clock T3111C and GG genotype of Bmal1 A1420G were significantly higher in the HOMA-IR positive group (29.1 vs. 10.8% P < .000 and 43.7 vs. 27.7% P = .007, respectively). Logistic regression analysis showed that C allele of Clock T3111C (OR = 4.128, CI 95% 2.313-7.368, p = .000) and GG genotype of Bmal1 A1420G (OR = 1.983, CI 95% 1.117-3.521, p = .019) were independent risk factors for potential HOMA-IR in Chinese patients with essential hypertension.Conclusion: Our results indicated that Chinese hypertensive patients with C allele of Clock T3111C or GG genotype of Bmal1 A1420G might be susceptible to IR and are more likely to develop high nighttime SBP.

Downregulation of Long Non-Coding RNA Kcnq1ot1: An Important Mechanism of Arsenic Trioxide-Induced Long QT Syndrome.

BACKGROUND/AIMS: Arsenic trioxide (ATO) is a known anti-acute promyelocytic leukemia (APL) reagent, whose clinical applications are limited by its serious cardiac toxicity and fatal adverse effects, such as sudden cardiac death resulting from long QT syndrome (LQTS). The mechanisms of cardiac arrhythmia due to ATO exposure still need to be elucidated. Long non-coding RNAs (lncRNAs) are emerging as major regulators of various pathophysiological processes. This study aimed to explore the involvement of lncRNAs in ATO-induced LQTS in vivo and in vitro. METHODS: For in vivo experiments, mice were administered ATO through the tail vein. For in vitro experiments, ATO was added to the culture medium of primary cultured neonatal mouse cardiomyocytes. To evaluate the effect of lncRNA Kcnq1ot1, siRNA and lentivirus-shRNA were synthesized to knockdown lncRNA Kcnq1ot1. RESULTS: After ATO treatment, the Kcnq1ot1 and Kcnq1 expression levels were down regulated. lncRNA Kcnq1ot1 knockdown prolonged the action potential duration (APD) in vitro and exerted LQTS in vivo. Correspondingly, Kcnq1 expression was decreased after silencing lncRNA Kcnq1ot1. However, the knockdown of Kcnq1 exerted no effect on lncRNA Kcnq1ot1 expression. CONCLUSIONS: To our knowledge, this report is the first to demonstrate that lncRNA Kcnq1ot1 downregulation is responsible for QT interval prolongation induced by ATO at least partially by repressing Kcnq1 expression. lncRNA Kcnq1ot1 has important pathophysiological functions in the heart and could become a novel antiarrhythmic target.

Dual transcriptomic analysis of Ostreid herpesvirus 1 infected Scapharca broughtonii with an emphasis on viral anti-apoptosis activities and host oxidative bursts.

The ark shell, Scapharca (Anadara) broughtonii, is an economically important marine shellfish species in Northwestern Pacific. Mass mortalities of ark shell adults related to Ostreid herpesvirus-1 (OsHV-1) infection have occurred frequently since 2012. However, due to the lack of transcriptomic resource of ark shells, the molecular mechanisms underpinning the virus-host interaction remains largely undetermined. In the present study, we resolved the dual transcriptome changes of OsHV-1 infected ark shell with Illumina sequencing. A total of 44 M sequence reads were generated, of which 67,119 reads were mapped to the OsHV-1 genome. De novo assembly of host reads resulted in 276,997 unigenes. 74,529 (26.90%), 47,653 (17.20%) and 19, 611 (7.07%) unigenes were annotated into GO, KOG and KEGG database, respectively. According to RSEM expression values, we identified 2998 differentially expressed genes (DEGs) between control and challenged groups, which included 2065 up-regulated unigenes and 933 down-regulated unigenes. Further analysis of functional pathways indicated that OsHV-1 could inhibit host cell apoptosis mainly by the up-regulation of inhibitor of apoptosis protein (IAP), and thus facilitating its successful replication. While host hemoglobins could induce oxidative burst by suppressing its peroxidase activity, and thus defense against OsHV-1 infection. Although we reported a narrow expression of the OsHV-1 genome compared to Crassostrea gigas infection, we highlighted several common viral genes highly expressed in the two hosts, suggesting an important functional role. This study offers insights into the pathogenesis mechanisms of OsHV-1 infection in bivalve mollusks of the Arcidae family.

Multi-Target Anti-Alzheimer Activities of Four Prenylated Compounds from Psoralea Fructus.

Alzheimer's disease (AD) is an age-related neurodegenerative disease that is mediated by multiple signaling pathways. In recent years, the components of Psoralea Fructus (PF) have demonstrated some anti-Alzheimer effects both in vitro and in vivo. To further reveal the active compounds of PF and their mechanisms regulating key targets of AD, in this study, we identified four prenylated compounds from the 70% ethanolic aqueous extract of PF, namely bavachin, bavachinin, bavachalcone, and isobavachalcone. Multi-target bioactivity analysis showed that these compounds could differentially inhibit neuroinflammation, oxidative damage, and key AD-related protein targets, such as amyloid ß-peptide 42, ß-secretase, glycogen synthase kinase 3ß, and acetylcholinesterase. These compounds may generate beneficial effects in AD prevention and treatment.

Expression, secretion and bactericidal activity of type VI secretion system in Vibrio anguillarum.

The type VI secretion system (T6SS) was recently shown to modulate quorum sensing and the stress response in Vibrio anguillarum serotype O1 strain NB10. It is not known whether there is a functionally active T6SS in other serotypes of V. anguillarum. Here, homologues to T6SS cluster VtsEFGH and hemolysin-coregulated protein (Hcp)-encoding genes were found to be prevalent and conserved in clinical isolates of V. anguillarum from fish, including four O1 and five non-O1 serotype strains. Unexpectedly, only the non-O1 serotype strains expressed VtsEFGH and Hcp under laboratory and marine-like conditions, in contrast to the serotype O1 strains. This suggested that the V. anguillarum non-O1 serotype strains tested have constitutive expression of T6SS. Examination of a representative non-O1 strain, MHK3, showed that Hcp production was growth phase dependent and that maximum Hcp production was observed in the exponential growth phase. Moreover, Hcp production by MHK3 was most active under warm marine-like conditions. Further examination revealed a correlation of the constitutive expression of T6SS with bactericidal activity against Escherichia coli and Edwardsiella tarda. The work presented here suggests that the constitutive expression of T6SS provides V. anguillarum with advantage in microbial competition in marine environments.

Comparative transcriptome profiling of Pyropia yezoensis (Ueda) M.S. Hwang & H.G. Choi in response to temperature stresses.

BACKGROUND: Pyropia yezoensis is a model organism often used to investigate the mechanisms underlying stress tolerance in intertidal zones. The digital gene expression (DGE) approach was used to characterize a genome-wide comparative analysis of differentially expressed genes (DEGs) that influence the physiological, developmental or biochemical processes in samples subjected to 4 treatments: high-temperature stress (HT), chilling stress (CS), freezing stress (FS) and normal temperature (NT). RESULTS: Equal amounts of total RNAs collected from 8 samples (two biological replicates per treatment) were sequenced using the Illumina/Solexa platform. Compared with NT, a total of 2202, 1334 and 592 differentially expressed unigenes were detected in HT, CS and FS respectively. Clustering analysis suggested P. yezoensis acclimates to low and high-temperature stress condition using different mechanisms: In heat stress, the unigenes related to replication and repair of DNA and protein processing in endoplasmic reticulum were active; however at low temperature stresses, unigenes related to carbohydrate metabolism and energy metabolism were active. Analysis of gene differential expression showed that four categories of DEGs functioning as temperature sensors were found, including heat shock proteins, H2A, histone deacetylase complex and transcription factors. Heat stress caused chloroplast genes down-regulated and unigenes encoding metacaspases up-regulated, which is an important regulator of PCD. Cold stress caused an increase in the expression of FAD to improve the proportion of polyunsaturated fatty acids. An up-regulated unigene encoding farnesyl pyrophosphate synthase was found in cold stress, indicating that the plant hormone ABA also played an important role in responding to temperature stress in P. yezoensis. CONCLUSION: The variation of amount of unigenes and different gene expression pattern under different temperature stresses indicated the complicated and diverse regulation mechanism in response to temperature stress in P. yezoensis. Several common metabolism pathways were found both in P. yezoensis and in higher plants, such as FAD in low-temperature stress and HSP in heat stress. Meanwhile, many chloroplast genes and unigene related to the synthesis of abscisic acid were detected, revealing its unique temperature-regulation mechanism in this intertidal species. This sequencing dataset and analysis may serve as a valuable resource to study the mechanisms involved in abiotic stress tolerance in intertidal seaweeds.

Generation and evaluation of virulence attenuated mutants of Edwardsiella tarda as vaccine candidates to combat edwardsiellosis in flounder (Paralichthys olivaceus).

Edwardsiella tarda is an intracellular pathogen that causes edwardsiellosis in fish. The development of a live attenuated vaccine may be an effective approach for preventing this disease in fish. In this study, we introduced deletions of esrB, esaC, evpH, rpoS, and purA into the E. tarda LSE40ΔaroA strain, thereby generating five double-gene mutants (ΔaroAΔesrB, ΔaroAΔesaC, ΔaroAΔrpoS, ΔaroAΔevpH, and ΔaroAΔpurA) and two triple-gene mutants (ΔaroAΔesrBΔevpH and ΔaroAΔesaCΔevpH). When blue gourami (Trichogaster trichopterus) was used as a fish model for the primary screening and evaluation of the vaccine candidates, all mutants were attenuated significantly by more than 2 to 3 logs in terms of the 50% lethal dose (LD(50)). Five double-gene mutants yielded relative percentage survival (RPS) rates of 26.1-82.6% after challenge with wild-type E. tarda. The ΔaroAΔesrB mutant that conferred the highest RPS (82.6%) in blue gourami was also evaluated in flounder (Paralichthys olivaceus). After vaccination via intramuscular (i.m.) injection or immersion, this mutant could persist in the flounder for 14-35 days and it induced higher serum antibody titers than the control fish (P < 0.01). Flounder vaccinated via i.m. injection at doses of 10(3)-10(7) CFU/fish had RPS rates of 14.3-66.7% after i.m. challenge with 10(4) CFU/fish using wild-type E. tarda. Flounder vaccinated via immersion at a dose of 10(7) CFU/ml exhibited 100% RPS against immersion challenge with 10(7) CFU/ml using wild-type E. tarda. These results indicate that the ΔaroAΔesrB mutant could be used as an effective live vaccine to combat edwardsiellosis in flounder.

Complete nucleotide sequence of Klebsiella phage P13 and prediction of an EPS depolymerase gene.

The complete genome of Klebsiella phage P13 was sequenced and analyzed. Bacteriophage P13 has a double-stranded linear DNA with a length of 45,976 bp and a G+C content of 51.7 %, which is slightly lower than that of Klebsiella pneumoniae KCTC 2242. The codon biases of phage P13 are very similar to those of SP6-like phages and K. pneumoniae KCTC 2242. Bioinformatics analysis shows that the phage P13 genome has 282 open reading frames (ORFs) that are greater than 100 bp in length, and 50 of these ORFs were identified as predicted genes with an average length of 833 bp. Among these genes, 41 show homology to known proteins in the GenBank database. The functions of the 24 putative proteins were investigated, and 13 of these were found to be highly conserved. According to the homology analysis of the 50 predicted genes and the whole genome, phage P13 is homologous to SP6-like phages. Furthermore, the morphological characteristics of phage P13 suggest that it belongs to the SP6-like viral genus of the Podoviridae subfamily Autographivirinae. Two hypothetical genes encoding an extracellular polysaccharide depolymerase were predicted using PSI-BLAST. This analysis serves as groundwork for further research and application of the enzyme.

Microporous poly(Schiff base) constructed from tetraphenyladamantane units for adsorption of gases and organic vapors.

A new microporous poly(Schiff base) (PSN-3) is constructed from 1,3,5,7-tetrakis(4-formylphenyl)adamantane and 1,3,5,7-tetrakis(4-aminophenyl)adamantane through an A4 -A4 ' reaction. The surface and internal morphologies of porous PSN-3 are examined by FE-SEM and HR-TEM. PSN-3 exhibits a BET surface area of 865 m(2) g(-1) with a major pore size around 0.6 nm. Moreover, PSN-3 can uptake 1.32 wt% H2 (77 K/1 bar), 13.6 wt% CO2 (273 K/1 bar), 80.5 wt% benzene, and 63.7 wt% cyclohexane (298 K/0.9 bar). The adsorption selectivities for CO2/N2, CO2/CH4, benzene/N2, and benzene/H2O are 88, 16, 267, and 19, respectively. The high adsorption capacities and selectivities for gases and vapors make PSN-3 a promising candidate for H2 storage, CO2 capture, and recovery of organic pollutants.

Case Report: A case suffered acute cerebral infarction after removal of temporary cardiac pacing lead which led to the perforation of interventricular septum.

We report an elderly male patient with frequent episodes of dizziness due to a complete atrioventricular block who underwent temporary pacemaker insertion in a local hospital. After the implantation of a permanent pacemaker and removal of the temporary pacemaker lead, the patient developed sudden neurological symptoms, upon which an acute cerebellar infarction was diagnosed via head CT. We will discuss the adequacy of the periprocedural administration.

Screening soy hydrolysates for the production of a recombinant therapeutic protein in commercial cell line by combined approach of near-infrared spectroscopy and chemometrics.

Soy hydrolysates are widely used as the major nutrient sources for cell culture processes for industrial manufacturing of therapeutic recombinant proteins. The primary goal of this study was to develop a spectroscopy based chemometric method, a partial least squares (PLS), to screen soy hydrolysates for better yield of protein production (titers) in cell culture medium. Harvest titer values of 29 soy hydrolysate lots with production yield between 490 and 1,350 mg/L were obtained from shake flask models or from manufacture engineering runs. The soy hydrolysate samples were measured by near-infrared (NIR) in reflectance mode using an infrared fiber optic probe. The fiber optic probe could easily enable in situ measurement of the soy hydrolysates for convenient raw material screening. The best PLS calibration has a determination coefficient of R (2) = 0.887 utilizing no spectral preprocessing, the two spectral ranges of 10,000-5,376 cm(-1) and 4,980-4,484 cm(-1), and a rank of 6 factors. The cross-validation of the model resulted in a determination coefficient of R (2) = 0.741 between the predicted and actual titer values with an average standard deviation of 72 mg/L. Compared with the resource demanding shake flask model, the combination of NIR and chemometric modeling provides a convenient method for soy hydrolysate screening with the advantage of fast speed, low cost and non-destructive.

Molecular cloning, characterization, and heterologous expression of a new κ-carrageenase gene from marine bacterium Zobellia sp. ZM-2.

κ-Carrageenases exhibit apparent distinctions in gene sequence, molecular weight, enzyme properties, and posttranslational processes. In this study, a new κ-carrageenase gene named cgkZ was cloned from the marine bacterium Zobellia sp. ZM-2. The gene comprised an open reading frame of 1,638 bp and encoded 545 amino acids. The natural signal peptide of κ-carrageenase was used successfully for the secretory production of the recombinant enzyme in Escherichia coli. A posttranslational process that removes an amino acid sequence of about 20 kDa from the C-terminal end of κ-carrageenase was first discovered in E. coli. An increase in enzyme activity by 167.3% in the presence of 5 mM DTT was discovered, and Na(+) at a certain concentration range was positively correlated with enzyme activity. The κ-carrageenase production of E. coli was 9.0 times higher than that of ZM-2. These results indicate the potential use of the enzyme in the biotechnological industry.

Phenotypic characterization, virulence, and immunogenicity of Edwardsiella tarda LSE40 aroA mutant.

Bacterial aro mutants are frequently used as live attenuated vaccines for domestic animals. In this study, we characterized Edwardsiella tarda strain LSE40 with a deletion in the aroA gene. In addition to autotrophy, the aroA mutant appeared to have delayed cell division and reductions in its swarming motility, biofilm formation, and production of translocator proteins in the type III secretory system. The mutant exhibited high virulence attenuation in turbot fish, Scophthalmus maximus (L.), where the 50 % lethal dose increased by more than 3 log10 via intraperitoneal (i.p.) injection and by >2 log10 via immersion exposure compared with the wild-type parent strain. A tissue persistence study showed that the mutant retained the ability to invade and spread in turbot and viable cells could be detected up to 28 days after i.p. infection and 21 days after immersion exposure. These results suggested a pleiotropic role for aroA in the physiological behavior of E. tarda. Turbot exhibited a good humoral response and the enhanced expression of innate immune factors, interleukin 1ß and lysozyme, when vaccinated with aroA mutant at 105 CFU via i.p. injection and at 108 CFU via immersion exposure. However, the aroA mutant did not provide effective protection for turbot against edwardsiellosis following i.p. vaccination at doses of 104-106 CFU or immersion vaccination at doses of 106-108 CFU ml⁻¹. We hypothesized that the aroA mutant did not trigger an appropriate T cell-immune response in turbot against infection of E. tarda.

Role of alternative sigma factor 54 (RpoN) from Vibrio anguillarum M3 in protease secretion, exopolysaccharide production, biofilm formation, and virulence.

The sigma factor σ(54) (RpoN) is an important regulator of bacterial response to environmental stresses. Here, we demonstrate the roles of RpoN in Vibrio anguillarum M3 by comparative investigation of physiological phenotypes and virulence of the wild-type, an rpoN mutant, and an rpoN complemented strain. Disruption of rpoN was found to decrease biofilm formation, production of exopolysaccharides, and production of the metalloproteases EmpA and PrtV. Injection experiments in fish showed that the M3 ΔrpoN mutant was attenuated in virulence when administrated either by intramuscular injection or by immersion challenge. Slower proliferation of the mutant in fish was also observed. Complementation of the mutant strain with rpoN restored some of the phenotypes to wild-type levels. RpoN was involved in regulation of some virulence-associated genes, as shown by real-time quantitative reverse PCR analysis. These results revealed a pleiotropic regulatory role of RpoN in biofilm formation, production of proteases and exopolysaccharides, and virulence in V. anguillarum M3.

A New Strategy to Improve the Toughness of Epoxy Thermosets-By Introducing Poly(ether nitrile ketone)s Containing Phthalazinone Structures.

As high brittleness limits the application of all epoxy resins (EP), here, it can be modified by high-performance thermoplastic poly(ether nitrile ketone) containing phthalazinone structures (PPENK). Therefore, the influence of different PPENK contents on the mechanical, thermal, and low-temperature properties of EP was comprehensively investigated in this paper. The binary blend of PPENK/EP exhibited excellent properties due to homogeneous mixing and good interaction. The presence of PPENK significantly improved the mechanical properties of EP, showing 131.0%, 14.2%, and 10.0% increases in impact, tensile, and flexural strength, respectively. Morphological studies revealed that the crack deflection and bridging in PPENK were the main toughening mechanism in the blend systems. In addition, the PPENK/EP blends showed excellent thermal and low-temperature properties (-183 °C). The glass transition temperatures of the PPENK/EP blends were enhanced by approximately 50 °C. The 15 phr of the PPENK/EP blends had a low-temperature flexural strength of up to 230 MPa, which was 46.5% higher than EP. Furthermore, all blends exhibited better thermal stability.

Case report: Catheter ablation for persistent atrial fibrillation in a patient with heart of stone.

Myocardial calcification is a rare condition, with only a few reports in the literature. For the first time, we report a case of diffuse myocardial calcification who underwent successful catheter ablation for persistent atrial fibrillation (AF). In this case, catheter ablation was recommended due to repeated hospitalization for palpitation and heart failure, but preoperative computed tomography showed massive myocardial calcification. Electroanatomic mapping of the atrium was performed with a Pentaray catheter before ablation, which showed areas of low voltage in the calcified region. As the persistent AF was terminated after circumferential pulmonary vein isolation and posterior wall isolation, and no further ablation was performed. The patient recovered well, with no recurrence of palpitation or heart failure during the one-year follow-up.