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Hepatocellular carcinoma (HCC) is the predominant form of primary liver cancer, accounting for approximately 90% of liver cancer cases. It currently ranks as the fifth most prevalent cancer worldwide and represents the third leading cause of cancer-related mortality. As a malignant disease with surgical resection and ablative therapy being the sole curative options available, it is disheartening that most HCC patients who undergo liver resection experience relapse within five years. Microvascular invasion (MVI), defined as the presence of micrometastatic HCC emboli within liver vessels, serves as an important histopathological feature and indicative factor for both disease-free survival and overall survival in HCC patients. Therefore, achieving accurate preoperative noninvasive prediction of MVI holds vital significance in selecting appropriate clinical treatments and improving patient prognosis. Currently, there are no universally recognized criteria for preoperative diagnosis of MVI in clinical practice. Consequently, extensive research efforts have been directed towards preoperative imaging prediction of MVI to address this problem and the relative research progresses were reviewed in this article to summarize its current limitations and future research prospects.
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Introduction: Investigating how circular RNAs (circRNAs) function during tumorigenesis may help uncover novel diagnostic markers for cancer treatment. The oncogenic role of circ_001621 has been verified in osteosarcoma, but its role in lung cancer has yet to be reported. This research is the first to investigate the circ_001621 expression and regulatory mechanism in lung cancer. Material and methods: RT-qPCR was performed to assess the circ_001621 expression levels in lung cancer cells and tissues. The influence of circ_001621 on the viability, invasive ability, and apoptosis of lung cancer cells was investigated through CCK-8, transwell, and caspase-3 activity experiments, respectively. A xenograft nude mouse model was designed to evaluate how circ_001621 functions in vivo. The RIP and luciferase reporter experiments confirmed the binding among circRNA, miRNA, and mRNA. Results: Circ_001621 was dramatically upregulated in lung cancer tissues and cells. Silencing circ_001621 in lung cancer cells reduced their viability and invasive ability but stimulated apoptosis. The nude mice experiment demonstrated that circ_001621 downregulation considerably stunted tumor growth in vivo. Additionally, circ_001621 could sponge miR-199a-3p. The inhibitor of miR-199a-3p improved the viability and invasion of cells while inhibiting apoptosis. Moreover, it offset the impact of circ_001621 on lung cancer cells. MiR-199a-3p was observed to target GREM1, and the downregulation of GREM1 could counteract miR-199a-3p-induced effects on lung cancer cells. Conclusions: The circ_001621/miR-199a-3p/GREM1 axis exhibits an association with the development of lung cancer, suggesting its potential as a future therapeutic target for the disease.
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Glioma is the most common malignant tumor of the central nervous system (CNS), and is characterized by high aggressiveness and a high recurrence rate. Currently, the main treatments for gliomas include surgical resection, temozolomide chemotherapy and radiotherapy. However, the prognosis of glioma patients after active standardized treatment is still poor, especially for glioblastoma (GBM); the median survival is still only 14.6 months, and the 5-year survival rate is only 4-5%. The current challenges in glioma treatment include difficulty in complete surgical resection, poor bloodâbrain barrier (BBB) drug permeability, therapeutic resistance, and difficulty in tumor-specific targeting. In recent years, the rapid development of nanotechnology has provided new directions for diagnosing and treating gliomas. Nanoparticles (NPs) are characterized by excellent surface tunability, precise targeting, excellent biocompatibility, and high safety. In addition, NPs can be used for gene therapy, photodynamic therapy, and antiangiogenic therapy and can be combined with biomaterials for thermotherapy. In recent decades, breakthroughs in diagnosing and treating gliomas have been made with various functional NPs, and NPs are expected to become a new strategy for glioma diagnosis and treatment. In this paper, we review the main obstacles in the treatment of glioma and discuss the potential and challenges of the latest nanotechnology in the diagnosis and treatment of glioma.
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Cancer immunotherapies are ineffective in nonresponding patients due to absence of immune responses. Here, we identified that dihydroartemisinin (DHA) induced immunogenic cell death (ICD) in hepatocellular carcinoma (HCC), proved by release or surface expose of damage-associated molecular patterns and in vivo protective vaccine activity. Mechanistically, DHA can inhibit cyclin-dependent kinases (CDKs), leading to a buildup of intracellular reactive oxygen species (ROS), which induces immunogenic cell death. In both Hepa1-6 and H22 tumor bearing mice, DHA exerted anti-tumor activity through increasing tumor-infiltrating CD8+ T cells with expression of activation makers (CD25 and CD69), secretion of intracellular cytokines (IFN-γ and TNF-α) and activated dendritic cells expressing MHCâ ¡, CD80 and CD86. In hepa1-6 tumor bearing mice, DHA decreased immunosuppressive myeloid-derived suppressor cells. Furthermore, DHA enhanced the anti-PD-1 antibody and chimeric antigen receptor (CAR) T cell-mediated tumor suppression through recruitment and activation of endogenous CD8+ T cells. Overall, we demonstrated that by inhibiting CDKs, DHA can remodel tumor micro-environment to amplify anti-tumor immune responses in HCC. These findings provide a promising therapy option for HCC patients.
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Artemisininas , Linfocitos T CD8-positivos , Carcinoma Hepatocelular , Quinasas Ciclina-Dependientes , Inmunoterapia , Neoplasias Hepáticas , Ratones Endogámicos C57BL , Microambiente Tumoral , Animales , Microambiente Tumoral/efectos de los fármacos , Microambiente Tumoral/inmunología , Artemisininas/farmacología , Artemisininas/uso terapéutico , Ratones , Carcinoma Hepatocelular/terapia , Carcinoma Hepatocelular/inmunología , Carcinoma Hepatocelular/tratamiento farmacológico , Neoplasias Hepáticas/inmunología , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Hepáticas/terapia , Quinasas Ciclina-Dependientes/antagonistas & inhibidores , Quinasas Ciclina-Dependientes/metabolismo , Línea Celular Tumoral , Humanos , Inmunoterapia/métodos , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Células Supresoras de Origen Mieloide/efectos de los fármacos , Células Supresoras de Origen Mieloide/inmunología , MasculinoRESUMEN
In order to study the effect of different warm mixing agents on the cooling and road performance of porous mixture bonded with High Viscosity Asphalt (HVA), the Superpave Gyratory Compactor (SGC) was proposed to conduct variable temperature compaction test on the warm mixed porous asphalt mixture. The relationship between the compaction difficulty coefficient and the temperature of the mixture was obtained by regression, and the mixing and compacting temperature and cooling effect of the warm mixed porous asphalt mixture were determined. Then, the influence of Evotherm M1 and EC120 warm mix agents on the performance of porous asphalt mixture was compared by rutting tests, beam bending tests, immersion Marshall tests, freeze-thaw splitting tests, and penetration strength tests. The results show that two types of warm mixing agents can reduce the mixing and rolling temperatures of the mixture by more than 10°C. The addition of warm mix agents will increase the high temperature stability, water stability, and shear resistance of porous asphalt mixtures. For the improvement effect of high temperature stability, EC120 warm mixing agent is greater than Evotherm M1 warm mixing agent, and for the improvement effect of water stability, Evotherm M1 warm mixing agent is greater than EC120 warm mixing agent. For shear resistance, the improvement effect of both is equivalent, with a penetration strength increase of about 3% to 4%. For low temperature performance, Evotherm M1 warm mixing agent improved the low temperature performance, while EC120 warm mixing agent showed the opposite effect.
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Materiales de Construcción , Hidrocarburos , Hidrocarburos/química , Porosidad , Viscosidad , Frío , Calor , Ensayo de MaterialesRESUMEN
: CRISPR/Cas12a-based combinational screening has shown remarkable potential for identifying genetic interactions. Here, we describe an innovative method for combinational genetic screening with rapid construction of a dual-CRISPR RNA (crRNA) library using gene splicing through overlap extension PCR (SOE PCR) and the adoption of CeCas12a, which we previously identified with strict PAM recognition and low off-targeting to guarantee fidelity and efficiency. The custom-pooled SOE crRNA array (SOCA) library for double-knockout screening could be conveniently constructed in the laboratory for widespread use, and the CeCas12a-mediated high-fidelity screen displayed good performance even under a negative selection screen. By designing a SOCA dual-crRNA library that covered most of the kinase and metabolism-associated gene targets of FDA-approved drugs implicated in hepatocellular carcinoma (HCC) tumourigenesis, novel cross-talk between the two gene sets was negatively selected to inhibit HCC cell growth in vitro and in vivo and was validated using virtual double-knockdown screening based on TCGA databases. Thus, this rapid, efficient and high-fidelity double-knockout screening system is promising for systemically identifying potential genetic interactions between multiple gene sets or combinations of FDA- approved drugs for clinical translational medicine in the future.
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Sistemas CRISPR-Cas , Carcinoma Hepatocelular , Neoplasias Hepáticas , Carcinoma Hepatocelular/genética , Neoplasias Hepáticas/genética , Humanos , Sistemas CRISPR-Cas/genética , Animales , Pruebas Genéticas/métodosRESUMEN
Tuberculosis (TB) is a prevalent and severe infectious disease that poses a significant threat to human health. However, it is frequently disregarded as there are not enough quick and accurate ways to diagnose tuberculosis. Here, we develop a strategy for tuberculosis detection to address the challenges, including an experimental strategy, namely, Double Adapter Directional Capture sequencing (DADCSeq), an easily operated and low-cost whole transcriptome sequencing method, and a computational method to identify hub differentially expressed genes as well as the diagnosis of TB based on whole transcriptome data using DADCSeq on peripheral blood mononuclear cells (PBMCs) from active TB and latent TB or healthy control. Applying our approach to create a robust and stable TB multi-mRNA risk probability model (TBMMRP) that can accurately distinguish active and latent TB patients, including active TB and healthy controls in clinical cohorts, this diagnostic biomarker was successfully validated by several independent cross-platform cohorts with favorable performance in differentiating active TB from latent TB or active TB from healthy controls and further demonstrated superior or similar diagnostic accuracy compared to previous diagnostic markers. Overall, we develop a low-cost and effective strategy for tuberculosis diagnosis; as the clinical cohort increases, we can expand to different disease kinds and learn new features through our disease diagnosis strategy.
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Biomarcadores , Transcriptoma , Tuberculosis , Humanos , Tuberculosis/diagnóstico , Tuberculosis/microbiología , Biomarcadores/análisis , Biomarcadores/sangre , Tuberculosis Latente/diagnóstico , Análisis Costo-Beneficio , Leucocitos Mononucleares , Perfilación de la Expresión Génica/métodos , Femenino , Mycobacterium tuberculosis/genética , Masculino , AdultoRESUMEN
OBJECTIVE: This study aimed to investigate the feasibility of using dual-layer spectral CT multi-parameter feature to predict microvascular invasion of hepatocellular carcinoma. METHODS: This retrospective study enrolled 50 HCC patients who underwent multiphase contrast-enhanced spectral CT studies preoperatively. Combined clinical data, radiological features with spectral CT quantitative parameter were constructed to predict MVI. ROC was applied to identify potential predictors of MVI. The CT values obtained by simulating the conventional CT scans with 70âkeV images were compared with those obtained with 40âkeV images. RESULTS: 50 hepatocellular carcinomas were detected with 30 lesions (Group A) with microvascular invasion and 20 (Group B) without. There were significant differences in AFP,tumer size, IC, NIC,slope and effective atomic number in AP and ICrr in VP between Group A ((1000(10.875,1000),4.360±0.3105, 1.7750 (1.5350,1.8825) mg/ml, 0.1785 (0.1621,0.2124), 2.0362±0.2108,8.0960±0.1043,0.2830±0.0777) and Group B (4.750(3.325,20.425),3.190±0.2979,1.4700 (1.4500,1.5775) mg/ml, 0.1441 (0.1373,0.1490),1.8601±0.1595, 7.8105±0.7830 and 0.2228±0.0612) (all pâ<â0.05). Using 0.1586 as the threshold for NIC, one could obtain an area-under-curve (AUC) of 0.875 in ROC to differentiate between tumours with and without microvascular invasion. AUC was 0.625 with CT value at 70âkeV and improved to 0.843 at 40âkeV. CONCLUSION: Dual-layer spectral CT provides additional quantitative parameters than conventional CT to enhance the differentiation between hepatocellular carcinoma with and without microvascular invasion. Especially, the normalized iodine concentration (NIC) in arterial phase has the greatest potential application value in determining whether microvascular invasion exists, and can offer an important reference for clinical treatment plan and prognosis assessment.
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Adding fruit tree branches to the compost pile in appropriate proportions is one of the methods used to address the challenge of tobacco waste recycling. However, the effects of different proportions of fruit tree branches on nicotine concentration and microbial diversity during tobacco waste composting have not been reported. In this study, a composting system with tobacco waste, cow dung, and fruit tree branches was established in a laboratory fermenter to assess the impact of adding 10%, 20%, and 30% fruit tree branches on quantity changes. In addition, the relationships between nicotine degradation, compost properties, enzyme activities, and microbial diversities were determined using biochemical assay methods and high-throughput sequencing. The results showed that adding appropriate proportions of fruit branch segments affected changes in physical and chemical properties during composting and promoted tobacco waste compost maturity. Aerobic composting effectively degraded nicotine in tobacco waste. Increased proportions of fruit branch segments led to elevations in nicotine degradation rates and enzyme activities related to lignocellulose degradation. The addition of fruit branches influenced the relative abundance and species of dominant bacteria and fungi at the phylum and genus levels. However, it did not significantly affect the relative abundance of the main bacterial genera involved in nicotine degradation. Nevertheless, it reduced the sensitivity of enzyme activity to nicotine content within heaps, increasing reliance on total nitrogen changes. The results of this study provide a theoretical basis for the utilization of tobacco waste in composting systems and indicate that fruit tree branches can enhance nicotine degradation efficiency during tobacco waste composting.
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Compostaje , Nicotiana , Nicotina , Nicotiana/metabolismo , Nicotina/metabolismo , Nicotina/análisis , Frutas , Microbiología del Suelo , ÁrbolesRESUMEN
AIMS: This study aims to investigate the mediating role of regulatory emotional self-efficacy and self-compassion in the relationship among anxiety, depression, body image distress and subjective well-being among women with polycystic ovary syndrome. DESIGN: A cross-sectional study. METHODS: The study recruited 510 women with polycystic ovary syndrome from a tertiary hospital affiliated with a university in Hunan Province, China. The study employed several tools to collect data, including the Generalized Anxiety Scale, the Patient Health Questionnaire-9, the Body Image States Scale, the Self-Compassion Scale, the Regulatory Emotional Self-Efficacy Scale and the Index of Well-being questionnaire. Data analysis was carried out using descriptive analysis, spearman correlation analysis, ordinary least squares regression and bootstrapping. RESULTS: The study's findings indicate that regulatory emotional self-efficacy and self-compassion both act as mediators in the connection between anxiety, depression, body image distress and subjective well-being among women with polycystic ovary syndrome. CONCLUSION: The study emphasizes the significance of regulatory emotional self-efficacy and self-compassion in promoting well-being among women with polycystic ovary syndrome. It also implies that interventions targeted at enhancing these factors could potentially enhance the subjective well-being of women affected by PCOS. IMPACT: Our study's primary contribution is to underscore the crucial mediating roles of regulatory emotional self-efficacy and self-compassion in the relationship among anxiety, depression, body image distress and subjective well-being. Our study indicates that clinical practitioners should prioritize improving the regulatory emotional self-efficacy and self-compassion of women with polycystic ovary syndrome, reducing their anxiety, depression and body image distress and improving their subjective well-being. REPORTING METHOD: This study was reported according to the Standards for Reporting Qualitative Research (SRQR). PATIENT OR PUBLIC CONTRIBUTION: No patient or public contribution outside of participation in the actual study for purposes of data collection.
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Backgrounds: Extracellular matrix (ECM) is an important component of tumor microenvironment, and its abnormal expression promotes tumor formation, progression and metastasis. Methods: Weighted gene co-expression network analysis (WGCNA) was used to identify ECM-related hub genes based on The Cancer Genome Atlas (TCGA) colon adenocarcinoma (COAD) data. COAD clinical samples were used to verify the expression of potential biomarkers in tumor tissues, and siRNA was used to explore the role of potential biomarkers in cell proliferation and epithelial-mesenchymal transition (EMT). Results: Three potential biomarkers (LEP, NGF and PCOLCE2) related to prognosis of COAD patients were identified and used to construct ERGPI. Immunohistochemical analysis of clinical samples showed that the three potential biomarkers were highly expressed in tumor tissues of COAD patients. Knockdown of LEP, NGF or PCOLCE2 inhibited COAD cell proliferation and EMT. Dictamnine inhibited tumor cell growth by binding to these three potential biomarkers based on molecular docking and transplanted tumor model. Conclusion: The three biomarkers can provide new ideas for the diagnosis and targeted therapy of COAD patients.
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Adenocarcinoma , Biomarcadores de Tumor , Neoplasias del Colon , Biología Computacional , Transición Epitelial-Mesenquimal , Matriz Extracelular , Humanos , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Neoplasias del Colon/genética , Neoplasias del Colon/patología , Neoplasias del Colon/diagnóstico , Neoplasias del Colon/metabolismo , Adenocarcinoma/genética , Adenocarcinoma/diagnóstico , Adenocarcinoma/metabolismo , Adenocarcinoma/patología , Biología Computacional/métodos , Matriz Extracelular/metabolismo , Animales , Transición Epitelial-Mesenquimal/genética , Ratones , Proliferación Celular/genética , Línea Celular Tumoral , Regulación Neoplásica de la Expresión Génica , Pronóstico , Microambiente Tumoral , Simulación del Acoplamiento Molecular , Perfilación de la Expresión Génica , Masculino , Redes Reguladoras de GenesRESUMEN
The CRISPR-associated endonuclease Cas12a has become a powerful genome-editing tool in biomedical research due to its ease of use and low off-targeting. However, the size of Cas12a severely limits clinical applications such as adeno-associated virus (AAV)-based gene therapy. Here, we characterized a novel compact Cas12a ortholog, termed EbCas12a, from the metagenome-assembled genome of a currently unclassified Erysipelotrichia. It has the PAM sequence of 5'-TTTV-3' (V = A, G, C) and the smallest size of approximately 3.47 kb among the Cas12a orthologs reported so far. In addition, enhanced EbCas12a (enEbCas12a) was also designed to have comparable editing efficiency with higher specificity to AsCas12a and LbCas12a in mammalian cells at multiple target sites. Based on the compact enEbCas12a, an all-in-one AAV delivery system with crRNA for Cas12a was developed for both in vitro and in vivo applications. Overall, the novel smallest high-fidelity enEbCas12a, this first case of the all-in-one AAV delivery for Cas12a could greatly boost future gene therapy and scientific research.
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Sistemas CRISPR-Cas , Dependovirus , Edición Génica , Vectores Genéticos , Dependovirus/genética , Humanos , Edición Génica/métodos , Vectores Genéticos/genética , Animales , Células HEK293 , Terapia Genética/métodos , Proteínas Asociadas a CRISPR/metabolismo , Proteínas Asociadas a CRISPR/genética , Ratones , Endodesoxirribonucleasas/metabolismo , Endodesoxirribonucleasas/genética , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismoRESUMEN
The effective regeneration of large bone defects via bone tissue engineering is challenging due to the difficulty in creating an osteogenic microenvironment. Inspired by the fibrillar architecture of the natural extracellular matrix, we developed a nanoscale bioengineering strategy to produce bone fibril-like composite scaffolds with enhanced osteogenic capability. To activate the surface for biofunctionalization, self-adaptive ridge-like nanolamellae were constructed on poly(ε-caprolactone) (PCL) electrospinning scaffolds via surface-directed epitaxial crystallization. This unique nanotopography with a markedly increased specific surface area offered abundant nucleation sites for Ca2+ recruitment, leading to a 5-fold greater deposition weight of hydroxyapatite than that of the pristine PCL scaffold under stimulated physiological conditions. Bone marrow mesenchymal stem cells (BMSCs) cultured on bone fibril-like scaffolds exhibited enhanced adhesion, proliferation, and osteogenic differentiation in vitro. In a rat calvarial defect model, the bone fibril-like scaffold significantly accelerated bone regeneration, as evidenced by micro-CT, histological histological and immunofluorescence staining. This work provides the way for recapitulating the osteogenic microenvironment in tissue-engineered scaffolds for bone repair.
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Regeneración Ósea , Células Madre Mesenquimatosas , Osteogénesis , Poliésteres , Ingeniería de Tejidos , Andamios del Tejido , Animales , Andamios del Tejido/química , Ratas , Regeneración Ósea/efectos de los fármacos , Células Madre Mesenquimatosas/citología , Osteogénesis/efectos de los fármacos , Osteogénesis/fisiología , Ingeniería de Tejidos/métodos , Poliésteres/química , Diferenciación Celular , Ratas Sprague-Dawley , Materiales Biomiméticos/química , Materiales Biomiméticos/farmacología , Células Cultivadas , Proliferación Celular , Cráneo/lesiones , Cráneo/patología , Durapatita/química , Durapatita/farmacologíaRESUMEN
Ginsenoside F1 has high medicinal values, which is a kind of rare triterpene saponin isolated from Panax plants. The extremely low content of ginsenoside F1 in herbs has limited its research and application in medical field. In this work, we constructed a pathway in tobacco for the biosynthesis of ginsenoside F1 by metabolic engineering. Four enzyme genes (PnDDS, CYP716A47, CYP716S1 and UGT71A56) isolated from Panax notoginseng were introduced into tobacco. Thus, a biosynthetic pathway for ginsenoside F1 synthesis was artificially constructed in tobacco cells; moreover, the four exogenous genes could be expressed in the roots, stems and leaves of transgenic plants. Consequently, ginsenoside F1 and its precursors were successfully synthesized in the transgenic tobacco, compared with Panax plants, the content of ginsenoside F1 in transgenic tobacco was doubled. In addition, accumulation of ginsenoside F1 and its precursors in transgenic tobacco shows organ specificity. Based on these results, a new approach was established to produce rare ginsenoside F1; meanwhile, such strategy could also be employed in plant hosts for the heterologous synthesis of other important or rare natural products.
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Ginsenósidos , Nicotiana , Plantas Modificadas Genéticamente , Ginsenósidos/biosíntesis , Ginsenósidos/metabolismo , Nicotiana/genética , Nicotiana/metabolismo , Plantas Modificadas Genéticamente/genética , Ingeniería Metabólica/métodos , Vías Biosintéticas/genéticaRESUMEN
Background: In patients with chronic aortic regurgitation (AR), the left ventricle (LV) develops compensatory mechanisms to sustain its function. LV global longitudinal strain (GLS) is a key means to detect subclinical LV dysfunction, even when LV ejection fraction (LVEF) remains within the normal range. Compared to GLS, Tissue motion annular displacement (TMAD) is a simpler strain-based method to assess LV systolic function. This study investigated the correlation among TMAD parameters, LVEF, and GLS, and determined the diagnostic value and threshold of TMAD parameters for left ventricular systolic dysfunction. Methods: A prospective study was conducted at a single center. The case and control groups consisted of patients with chronic severe AR and healthy volunteers, respectively. Speckle-tracking echocardiography (STE) was used to assess the GLS and TMAD parameters in the apical 4-chamber and apical 2-chamber. Subsets of participants were analyzed for inter- and intra-observer variability and analysis time. A correlation analysis was performed among the TMAD parameters, LVEF, and GLS. Receiver operating characteristic curves and the area under the curves (AUCs) were used to evaluate the predictive value of the TMAD parameters for LVEF <50% and GLS > -18%. Results: This study involved 96 patients with severe chronic AR and 45 healthy volunteers. Compared to GLS, TMAD demonstrated superior intra- and inter-observer consistency and shorter average analysis time. Biplane global Midpt% showed the highest correlation with GLS and LVEF among all the TMAD parameters, with r values of 0.81 and 0.74, respectively. Furthermore, global Midpt% had AUCs of 0.89 and 0.92 for predicting LVEF< 50% and GLS > -18%, respectively. Conclusion: The TMAD global Midpt% has the potential to replace GLS in clinical practice and find wide applications.
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The clustered regularly interspaced short palindromic repeat (CRISPR)-Cas12a system is a powerful tool in gene editing; however, crRNA-DNA mismatches might induce unwanted cleavage events, especially at the distal end of the PAM. To minimize this limitation, we engineered a hyper fidelity AsCas12a variant carrying the mutations S186A/R301A/T315A/Q1014A/K414A (termed HyperFi-As) by modifying amino acid residues interacting with the target DNA and crRNA strand. HyperFi-As retains on-target activities comparable to wild-type AsCas12a (AsCas12aWT) in human cells. We demonstrated that HyperFi-As has dramatically reduced off-target effects in human cells, and HyperFi-As possessed notably a lower tolerance to mismatch at the position of the PAM-distal region compared with the wild type. Further, a modified single-molecule DNA unzipping assay at proper constant force was applied to evaluate the stability and transient stages of the CRISPR/Cas ribonucleoprotein (RNP) complex. Multiple states were sensitively detected during the disassembly of the DNA-Cas12a-crRNA complexes. On off-target DNA substrates, the HyperFi-As-crRNA was harder to maintain the R-loop complex state compared to the AsCas12aWT, which could explain exactly why the HyperFi-As has low off-targeting effects in human cells. Our findings provide a novel version of AsCas12a variant with low off-target effects, especially capable of dealing with the high off-targeting in the distal region from the PAM. An insight into how the AsCas12a variant behaves at off-target sites was also revealed at the single-molecule level and the unzipping assay to evaluate multiple states of CRISPR/Cas RNP complexes might be greatly helpful for a deep understanding of how CRISPR/Cas behaves and how to engineer it in future.
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Sistemas CRISPR-Cas , Edición Génica , Humanos , Sistemas CRISPR-Cas/genética , ARN Guía de Sistemas CRISPR-Cas , Endonucleasas/genética , Endonucleasas/metabolismo , ADN/genéticaRESUMEN
The rheological properties of asphalt can well reflect its road performance, but the rheological properties of warm mix high viscosity asphalt (HVA) are unclear. In order to study the effect of warm mixing agent on rheological properties of HVA, two kinds of warm mixing agent EC120 (EC) and Evotherm M1 (M1) were selected to prepare warm mix HVA. The rheological properties of warm mix HVA at high temperature (135~195°C), medium temperature (0~80°C) and low temperature (-6~18°C) were studied by Brinell rotary viscosity test, dynamic shear rheological test (including temperature scanning, frequency scanning, linear amplitude scanning) and bending beam rheological test. The test results show that both EC and M1 have good viscosity reduction effect on HVA at high temperature, and can effectively reduce the construction temperature. At medium temperature, M1 can effectively improve the fatigue resistance of HVA, and the fatigue life can be increased by about 30% when the dosage is 0.6%. EC can increase the rutting factor of HVA and improve its resistance to deformation, but it will reduce its fatigue performance. When the dosage is 4%, the fatigue life will be reduced by about 9%. At low temperature, M1 can reduce the creep stiffness S, increase the creep rate m, and improve the low temperature performance of HVA, while EC has the opposite effect, weakening the low temperature performance of HVA. The results are helpful to understand the rheological properties of warm mix HVA and promote its application.
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Frío , Hidrocarburos , Temperatura , ViscosidadRESUMEN
Panax ginseng as a traditional medicinal plant with a long history of medicinal use. Ginsenoside Ro is the only oleanane-type ginsenoside in ginseng, and has various pharmacological activities, including anti-inflammatory, detoxification, and antithrombotic activities. UDP-dependent glycosyltransferase (UGT) plays a key role in the synthesis of ginsenoside, and the excavation of UGT genes involved in the biosynthesis of ginsenoside Ro has great significance in enriching ginsenoside genetic resources and further revealing the synthesis mechanism of ginsenoside. In this work, ginsenoside-Ro-synthesis-related genes were mined using the P. ginseng reference-free transcriptome database. Fourteen hub transcripts were identified by differential expression analysis and weighted gene co-expression network analysis. Phylogenetic and synteny block analyses of PgUGAT252645, a UGT transcript among the hub transcripts, showed that PgUGAT252645 belonged to the UGT73 subfamily and was relatively conserved in ginseng plants. Functional analysis showed that PgUGAT252645 encodes a glucuronosyltransferase that catalyzes the glucuronide modification of the C3 position of oleanolic acid using uridine diphosphate glucuronide as the substrate. Furthermore, the mutation at 622 bp of its open reading frame resulted in amino acid substitutions that may significantly affect the catalytic activity of the enzyme, and, as a consequence, affect the biosynthesis of ginsenoside Ro. Results of the in vitro enzyme activity assay of the heterologous expression product in E. coli of PgUGAT252645 verified the above analyses. The function of PgUGAT252645 was further verified by the result that its overexpression in ginseng adventitious roots significantly increased the content of ginsenoside Ro. The present work identified a new UGT gene involved in the biosynthesis of ginsenoside Ro, which not only enriches the functional genes in the ginsenoside synthesis pathway, but also provides the technical basis and theoretical basis for the in-depth excavation of ginsenoside-synthesis-related genes.