ABSTRACT
The occurrence of plant disease is determined by interactions among host, pathogen, and environment. Air humidity shapes various aspects of plant physiology and high humidity has long been known to promote numerous phyllosphere diseases. However, the molecular basis of how high humidity interferes with plant immunity to favor disease has remained elusive. Here we show that high humidity is associated with an "immuno-compromised" status in Arabidopsis plants. Furthermore, accumulation and signaling of salicylic acid (SA), an important defense hormone, are significantly inhibited under high humidity. NPR1, an SA receptor and central transcriptional co-activator of SA-responsive genes, is less ubiquitinated and displays a lower promoter binding affinity under high humidity. The cellular ubiquitination machinery, particularly the Cullin 3-based E3 ubiquitin ligase mediating NPR1 protein ubiquitination, is downregulated under high humidity. Importantly, under low humidity the Cullin 3a/b mutant plants phenocopy the low SA gene expression and disease susceptibility that is normally observed under high humidity. Our study uncovers a mechanism by which high humidity dampens a major plant defense pathway and provides new insights into the long-observed air humidity influence on diseases.
Subject(s)
Arabidopsis Proteins , Arabidopsis , Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , Salicylic Acid/metabolism , Humidity , Cullin Proteins/genetics , Cullin Proteins/metabolism , Arabidopsis/metabolism , Plants/metabolism , Transcription Factors/metabolism , Plant Diseases/genetics , Gene Expression Regulation, PlantABSTRACT
The plant immune system is fundamental for plant survival in natural ecosystems and for productivity in crop fields. Substantial evidence supports the prevailing notion that plants possess a two-tiered innate immune system, called pattern-triggered immunity (PTI) and effector-triggered immunity (ETI). PTI is triggered by microbial patterns via cell surface-localized pattern-recognition receptors (PRRs), whereas ETI is activated by pathogen effector proteins via predominantly intracellularly localized receptors called nucleotide-binding, leucine-rich repeat receptors (NLRs)1-4. PTI and ETI are initiated by distinct activation mechanisms and involve different early signalling cascades5,6. Here we show that Arabidopsis PRR and PRR co-receptor mutants-fls2 efr cerk1 and bak1 bkk1 cerk1 triple mutants-are markedly impaired in ETI responses when challenged with incompatible Pseudomonas syrinage bacteria. We further show that the production of reactive oxygen species by the NADPH oxidase RBOHD is a critical early signalling event connecting PRR- and NLR-mediated immunity, and that the receptor-like cytoplasmic kinase BIK1 is necessary for full activation of RBOHD, gene expression and bacterial resistance during ETI. Moreover, NLR signalling rapidly augments the transcript and/or protein levels of key PTI components. Our study supports a revised model in which potentiation of PTI is an indispensable component of ETI during bacterial infection. This revised model conceptually unites two major immune signalling cascades in plants and mechanistically explains some of the long-observed similarities in downstream defence outputs between PTI and ETI.
Subject(s)
Arabidopsis/immunology , NLR Proteins/immunology , Plant Immunity/immunology , Receptors, Pattern Recognition/immunology , Arabidopsis/genetics , Arabidopsis/microbiology , Arabidopsis Proteins/metabolism , NADPH Oxidases/metabolism , Plant Diseases/genetics , Plant Diseases/immunology , Plant Diseases/microbiology , Protein Serine-Threonine Kinases/metabolism , Pseudomonas syringae/immunology , Reactive Oxygen Species/metabolism , Signal Transduction/immunologyABSTRACT
Air humidity significantly impacts plant physiology. However, the upstream elements that mediate humidity sensing and adaptive responses in plants remain largely unexplored. In this study, we define high humidity-induced cellular features of Arabidopsis plants and take a quantitative phosphoproteomics approach to obtain a high humidity-responsive landscape of membrane proteins, which we reason are likely the early checkpoints of humidity signaling. We found that a brief high humidity exposure (i.e., 0.5 h) is sufficient to trigger extensive changes in membrane protein abundance and phosphorylation. Enrichment analysis of differentially regulated proteins reveals high humidity-sensitive processes such as 'transmembrane transport', 'response to abscisic acid', and 'stomatal movement'. We further performed a targeted screen of mutants, in which high humidity-responsive pathways/proteins are disabled, to uncover genes mediating high humidity sensitivity. Interestingly, ethylene pathway mutants (i.e., ein2 and ein3eil1) display a range of altered responses, including hyponasty, reactive oxygen species level, and responsive gene expression, to high humidity. Furthermore, we observed a rapid induction of ethylene biosynthesis genes and ethylene evolution after high humidity treatment. Our study sheds light on the potential early signaling events in humidity perception, a fundamental but understudied question in plant biology, and reveals ethylene as a key modulator of high humidity responses in plants.
Subject(s)
Arabidopsis Proteins , Arabidopsis , Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , Humidity , Ethylenes/metabolism , Arabidopsis/metabolism , Membrane Proteins/metabolism , Gene Expression Regulation, PlantABSTRACT
The widespread presence of formaldehyde (HCHO) pollutant has aroused significant environmental and health concerns. The catalytic oxidation of HCHO into CO2 and H2O at ambient temperature is regarded as one of the most efficacious and environmentally friendly approaches; to achieve this, however, accelerating the intermediate formate species formation and decomposition remains an ongoing obstacle. Herein, a unique tandem catalytic system with outstanding performance in low-temperature HCHO oxidation is proposed on well-structured Pd/Mn3O4-MnO catalysts possessing bifunctional catalytic centers. Notably, the optimized tandem catalyst achieves complete oxidation of 100 ppm of HCHO at just 18 °C, much better than the Pd/Mn3O4 (30%) and Pd/MnO (27%) counterparts as well as other physical tandem catalysts. The operando analyses and physical tandem investigations reveal that HCHO is primarily activated to gaseous HCOOH on the surface of Pd/Mn3O4 and subsequently converted to H2CO3 on the Pd/MnO component for deep decomposition. Theoretical studies disclose that Pd/Mn3O4 exhibits a favorable reaction energy barrier for the HCHO â HCOOH step compared to Pd/MnO; while conversely, the HCOOH â H2CO3 step is more facilely accomplished over Pd/MnO. Furthermore, the nanoscale intimacy between two components enhances the mobility of lattice oxygen, thereby facilitating interfacial reconstruction and promoting interaction between active sites of Pd/Mn3O4 and Pd/MnO in local vicinity, which further benefits sustained HCHO tandem catalytic oxidation. The tandem catalysis demonstrated in this work provides a generalizable platform for the future design of well-defined functional catalysts for oxidation reactions.
Subject(s)
Formaldehyde , Palladium , Temperature , Catalytic Domain , Oxidation-Reduction , Catalysis , Palladium/chemistryABSTRACT
Oxygenated volatile organic compounds (OVOCs), emitted in large quantities by the chemical industry, are a major contributor to the formation of ozone and subsequent particulate matter. For the efficient catalytic oxidation of OVOCs, the challenges of molecular activation and intermediate inhibition remain. The construction of bifunctional active sites with specific structures offers a promising way to overcome these problems. Here, the Pd@Layered-CoOx/MFI bifunctional catalyst with core-shell active sites was rationally fabricated though a two-step ligand pyrolysis method, which exhibits a superb oxidation efficiency toward ethyl acetate (EA). Over this, 13.4% of EA (1000 ppm) can be oxidized at just 140 °C with a reaction rate of 13.85 mmol·gPd-1·s-1, around 176.7 times higher than that of the conventional Pd-CoOx/MFI catalyst. The electronic coupling of the Pd-Co pair promotes the electron back-donation from Pd nanoparticles to the layered CoOx shell and facilitates the formation of Pd2+ species, which greatly enhances the adsorption and activation of the electron-rich CâO bond of the EA molecules. In addition, the synergy of these core-shell Pd@Layered-CoOx sites accelerates the activation and transformation of *O species, which inhibit the formation of acetaldehyde and ethanol byproducts, ensuring the rapid total oxidation of EA molecules via the Mars-van Krevelen mechanism. This work established a solid foundation for exploring robust bifunctional catalysts for deep OVOC purification.
Subject(s)
Oxidation-Reduction , Catalysis , Palladium/chemistry , Volatile Organic Compounds/chemistry , Acetates/chemistryABSTRACT
BACKGROUND: Light-harvesting chlorophyll a/b b evelopment of higher plants and in response to abiotic stress. Previous works has demonstrated that that Lhcb genes were involved in the phytochrome regulation and responded to the different light and temperature conditions in Poaceae (such as maize). However, the evolution and functions of Lhcb genes remains poorly characterized in important Rosaceae species. RESULTS: In this investigation, we conducted a genome-wide analysis and identified a total of 212 Lhcb genes across nine Rosaceae species. Specifically, we found 23 Lhcb genes in Fragaria vesca, 20 in Prunus armeniaca, 33 in Malus domestica 'Gala', 21 in Prunus persica, 33 in Rosa chinensis, 29 in Pyrus bretschneideri, 18 in Rubus occidentalis, 20 in Prunus mume, and 15 in Prunus salicina. Phylogenetic analysis revealed that the Lhcb gene family could be classified into seven major subfamilies, with members of each subfamily sharing similar conserved motifs. And, the functions of each subfamily was predicted based on the previous reports from other species. The Lhcb proteins were highly conserved within their respective subfamilies, suggesting similar functions. Interestingly, we observed similar peaks in Ks values (0.1-0.2) for Lhcb genes in apple and pear, indicating a recent whole genome duplication event (about 30 to 45 million years ago). Additionally, a few Lhcb genes underwent tandem duplication and were located across all chromosomes of nine species of Rosaceae. Furthermore, the analysis of the cis-acting elements in the 2000 bp promoter region upstream of the pear Lhcb gene revealed four main categories: light response correlation, stress response correlation, hormone response correlation, and plant growth. Quantitative expression analysis demonstrated that Lhcb genes exhibited tissue-specific expression patterns and responded differently to low-temperature stress in Rosaceae species. CONCLUSIONS: These findings shed light on the evolution and phylogeny of Lhcb genes in Rosaceae and highlight the critical role of Lhcb in pear's response to low temperatures. The results obtained provide valuable insights for further investigations into the functions of Lhcb genes in Rosaceae, and these functional genes will be used for further fruit tree breeding and improvement to cope with the current climate changes.
Subject(s)
Malus , Pyrus , Rosaceae , Rosaceae/genetics , Rosaceae/metabolism , Fruit/genetics , Fruit/metabolism , Phylogeny , Chlorophyll A/metabolism , Genome, Plant/genetics , Plant Breeding , Malus/genetics , Malus/metabolism , Pyrus/genetics , Genomics , Evolution, Molecular , Plant Proteins/genetics , Plant Proteins/metabolismABSTRACT
Multi-drug resistant (MDR) bacterial infections are gradually increasing in the global scope, causing a serious burden to patients and society. The formation of bacterial biofilms, which is one of the key reasons for antibiotic resistance, blocks antibiotic penetration by forming a physical barrier. Nano/micro motors (MNMs) are micro-/nanoscale devices capable of performing complex tasks in the bacterial microenvironment by transforming various energy sources (including chemical fuels or external physical fields) into mechanical motion or actuation. This autonomous movement provides significant advantages in breaking through biological barriers and accelerating drug diffusion. In recent years, MNMs with high penetrating power have been used as carriers of antibiotics to overcome bacterial biofilms, enabling efficient drug delivery and improving the therapeutic effectiveness of MDR bacterial infections. Additionally, non-antibiotic antibacterial strategies based on nanomaterials, such as photothermal therapy and photodynamic therapy, are continuously being developed due to their non-invasive nature, high effectiveness, and non-induction of resistance. Therefore, multifunctional MNMs have broad prospects in the treatment of MDR bacterial infections. This review discusses the performance of MNMs in the breakthrough and elimination of bacterial biofilms, as well as their application in the field of anti-infection. Finally, the challenges and future development directions of antibacterial MNMs are introduced.
Subject(s)
Bacterial Infections , Nanostructures , Humans , Nanotechnology , Anti-Bacterial Agents/pharmacology , Bacteria , BiofilmsABSTRACT
The development of highly active single-atom catalysts (SACs) and identifying their intrinsic active sites in oxidizing industrial hazardous hydrocarbons are challenging prospects. Tuning the electronic metal-support interactions (EMSIs) is valid for modulating the catalytic performance of SACs. We propose that the modulation of the EMSIs in a Pt1 -CuO SAC significantly promotes the activity of the catalyst in acetone oxidation. The EMSIs promote charge redistribution through the unified Pt-O-Cu moieties, which modulates the d-band structure of atomic Pt sites, and strengthens the adsorption and activation of reactants. The positively charged Pt atoms are superior for activating acetone at low temperatures, and the stretched Cu-O bonds facilitate the activation of lattice oxygen atoms to participate in subsequent oxidation. We believe that this work will guide researchers to engineer efficient SACs for application in hydrocarbon oxidation reactions.
ABSTRACT
BACKGROUND: Left bundle branch (LBB) pacing has emerged as a novel pacing modality. Left ventricular activation time (LVAT) was reported to be associated with the activation via LBB, but the value of LVAT for determining LBB pacing was unknown. We conducted a pilot study to determine if LVAT could define LBB capture by validating left ventricular (LV) mechanical synchrony. METHODS: We analyzed LVAT in 68 bradycardia-indicated patients who received LBB pacing. LVAT was measured from the stimulus to R-wave peak in lead V5 and V6. LV mechanical synchrony assessed by SPECT MPI was compared according to the value of LVAT and the presence of LBB potential. RESULTS: The mean LVAT was 75.4 ± 12.7 ms. LBB potential was recorded in 47 patients (69.1%). Patients with LVAT < 76 ms had better LV mechanical synchrony than those with LVAT ≥ 76 ms. Patients with LVAT < 76 ms or LBB potential had better mechanical synchrony than those with LVAT ≥ 76 ms and no potential. LVAT < 76 ms could predict the normal synchrony with a sensitivity of 88.9% and a specificity of 87.5%. CONCLUSION: A short LVAT indicated favorable mechanical synchrony in SPECT imaging. LVAT < 76 ms might be a practical parameter for defining LBB capture.
Subject(s)
Arrhythmias, Cardiac/therapy , Cardiac Pacing, Artificial , Heart Conduction System/physiopathology , Ventricular Dysfunction, Left/diagnostic imaging , Ventricular Dysfunction, Left/physiopathology , Aged , Arrhythmias, Cardiac/diagnostic imaging , Arrhythmias, Cardiac/physiopathology , Cardiac-Gated Single-Photon Emission Computer-Assisted Tomography , Female , Humans , Male , Middle Aged , Myocardial Perfusion Imaging , Pilot Projects , Predictive Value of Tests , Reproducibility of Results , Ventricular SeptumABSTRACT
Because of the sophisticated error cancellation in the density functional theory (DFT)-based calculations, a theoretically more accurate input would not guarantee a better output. In this work, our first-principles GW plus Bethe-Salpeter equation calculations using pseudopotentials show that cuprous halides (CuCl and CuBr) are such extreme cases for which a better one-electron band is not accompanied with a better exciton binding energy. Moreover, we find that the exchange interaction of Cu core electrons plays a crucial role in their ground-state electronic properties, especially in the energy gap and macroscopic dielectric constant. Our work provides new insights into the understanding of the electronic structure of cuprous halides from the DFT perspective.
ABSTRACT
Colorectal cancer (CRC) is the second leading malignancy worldwide. Accurate screening is pivotal to early CRC detection, yet current screening modality involves invasive colonoscopy while non-invasive FIT tests have limited sensitivity. We applied a DNA methylation assay to identify biomarkers for early-stage CRC detection, risk stratification and precancerous lesion screening at tissue level. A model of biomarkers SFMBT2, ITGA4, THBD and ZNF304 showed 96.1% sensitivity and 87.0% specificity in CRC detection, with 100.0% sensitivity for advanced precancerous lesion and stage I CRC. Performances were further validated with TCGA data set, which showed a consistent AUC of 0.99 and exhibited specificity against other cancer types. KCNJ12, VAV3-AS1 and EVC were further identified for stage stratification (stage 0-I versus stage II-IV), with AUC of 0.87, 83.0% sensitivity and 71.2% specificity. Additionally, dual markers of NEUROD1 and FAM72C showed 83.2% sensitivity and 77.4% specificity in differing non-advanced precancerous lesions from inflammatory bowel diseases.
Subject(s)
Colorectal Neoplasms/diagnosis , DNA Methylation , Adolescent , Adult , Aged , Biomarkers, Tumor/metabolism , Child , Colorectal Neoplasms/genetics , Colorectal Neoplasms/metabolism , Colorectal Neoplasms/pathology , Disease Progression , Female , Humans , Inflammatory Bowel Diseases/diagnosis , Male , Middle Aged , Neoplasm Staging , Precancerous Conditions/diagnosis , Young AdultABSTRACT
BACKGROUND: Left bundle branch area pacing (LBBAP) was reported to improve cardiac function by correcting complete left bundle branch block (CLBBB). Our study aimed to compare the efficacy of LBBAP and biventricular pacing (BIVP) in heart failure patients with CLBBB. METHODS: Ten patients prospectively underwent LBBAP (LBB-CRT group) and 30 patients received BIVP (BIV-CRT group) were matched using propensity score matching. LBBAP was achieved by the trans-interventricular septum method. Echocardiography, electrocardiogram, NYHA classification, and blood B-type natriuretic peptide concentration were evaluated at preimplantation and at 6-month follow up. CRT response was defined as at least 15% decrease in left ventricular end-systolic volume. RESULTS: In the LBB-CRT group, CLBBB were successfully corrected by LBBAP with no complications. QRS duration (QRSd) significantly decreased after implantation in both groups, and the decrease of QRSd in the LBB-CRT group was significantly greater than that in the BIV-CRT group (60.80 ± 20.09 vs. 33.00 ± 21.48 ms, p = .0009). The echocardiographic measurements including left ventricular end-diastolic diameter, left ventricular end-systolic diameter, and left ventricular ejection fraction significantly improved after 6 months in both groups. The response rate was significantly higher in LBB-CRT group than BIV-CRT group (100.00% vs. 63.33%, p = .038). The percentage of patients in New York Heart Association classification Grades I and II was significantly higher in the LBB-CRT group compared with that in the BIV-CRT group (median 1.5 vs. 2.0, p = .029) at 6-month follow-up. CONCLUSIONS: It is effective and safe to correct CLBBB with LBBAP in heart failure patients. Compared with BIVP, LBBAP can better optimize electrical synchrony and improve cardiac function.
Subject(s)
Cardiac Resynchronization Therapy , Heart Failure , Cardiac Pacing, Artificial , Case-Control Studies , Electrocardiography , Heart Failure/diagnosis , Heart Failure/therapy , Humans , Stroke Volume , Treatment Outcome , Ventricular Function, LeftABSTRACT
While various excitonic insulators have been studied in the literature, due to the perceived too-small spin splitting, spin-triplet excitonic insulator is rare. In two-dimensional systems such as a semihydrogenated graphene (known as graphone), however, it is possible, as revealed by first-principles calculations coupled with Bethe-Salpeter equation. The critical temperature, given by an effective Hamiltonian, is 11.5 K. While detecting excitonic insulators is still a daunting challenge, the condensation of triplet excitons will result in spin superfluidity, which can be directly measured by a transport experiment. Nonlocal dielectric screening also leads to an unexpected phenomenon, namely, an indirect-to-direct transition crossover between single-particle band and exciton dispersion in the semihydrogenated graphene, which offers yet another test by experiment.
ABSTRACT
AIMS: His-Purkinje system (HPS) pacing, including His bundle (HB) and left bundle branch (LBB) pacing, has emerged as a highlighted topic in recent years. Comparisons in lead performance and clinical outcomes between HB and LBB pacing were seldom reported. We aimed to investigate the mid-long-term lead performance and clinical outcomes of permanent HPS pacing patients in our centre. METHODS AND RESULTS: Permanent HB pacing was implemented by placing the pacing lead helix at the HB area. Left bundle branch pacing was achieved by placing the lead helix in the left-side sub-endocardium of the interventricular septum. Pacing parameters, 12-lead ECG, echocardiography, and clinical outcomes were evaluated during follow-up. A total of 64 patients with HB pacing and 185 with LBB pacing were included. Left bundle branch pacing exhibited a slightly longer paced QRS duration than HB pacing (117.7 ± 11.0 vs. 113.7 ± 19.8 ms, P = 0.04). Immediate post-operation, LBB pacing had a significant higher R-wave amplitude (16.5 ± 7.5 vs. 4.3 ± 3.6 mV, P < 0.001) and lower capture threshold (0.5 ± 0.1 vs. 1.2 ± 0.8 V, P < 0.001) compared with HB pacing. During follow-up, an increase in capture threshold of >1.0 V from baseline was found in eight (12.5%) patients in the HB pacing group and none in LBB pacing. Paced QRS morphology changed from Qr to QS in lead V1 in seven patients (3.8%) with LBB pacing. Both HB and LBB pacing preserved cardiac function in patients with left ventricular ejection fraction (LVEF) over 50%. In patients with LVEF <50%, both HB and LBB pacing improved clinical outcomes during follow-up. CONCLUSION: His-Purkinje system pacing produced favourable electrical synchrony and improved cardiac function in patients with heart failure. Left bundle branch pacing showed superior pacing parameters over HB pacing. Lead micro-displacement with changes in paced QRS morphology posts a concern in LBB pacing.
Subject(s)
Cardiac Pacing, Artificial , Ventricular Function, Left , Bundle of His , Electrocardiography , Humans , Stroke VolumeABSTRACT
The main task for real-time vehicle tracking is establishing associations with objects in consecutive frames. After occlusion occurs between vehicles during the tracking process, the vehicle is given a new ID when it is tracked again. In this study, a novel method to track vehicles between video frames was constructed. This method was applied on driving recorder sensors. The neural network model was trained by YOLO v3 and the system collects video of vehicles on the road using a driving data recorder (DDR). We used the modified Deep SORT algorithm with a Kalman filter to predict the position of the vehicles and to calculate the Mahalanobis, cosine, and Euclidean distances. Appearance metrics were incorporated into the cosine distances. The experiments proved that our algorithm can effectively reduce the number of ID switches by 29.95% on the model trained on the BDD100K dataset, and it can reduce the number of ID switches by 32.16% on the model trained on the COCO dataset.
ABSTRACT
OBJECTIVES: To evaluate the response to cardiac resynchronization therapy (CRT) and the correlation between CRT and pulmonary artery hemodynamic parameters. METHODS: The patients with chronic heart failure indicator for CRT were enrolled. The left ventricular end-systolic volume (LVESV) was measured by echocardiography and New York Heart Association (NYHA) classification was evaluated between one week before and six months after CRT. Mean pulmonary artery pressure (mPAP), pulmonary artery systolic pressure (PASP) and pulmonary vascular resistance (PVR) were measured by right heart catheterization. Left ventricular reverse remodeling (LVRR) is defined as a decrease of 15% or more in LVESV at the 6th month after CRT; Clinical response is defined as a decrease of NYHA classification at or above grade 1 at the 6th month after CRT. Pulmonary hypertension (PH) was defined as mPAP≥25 mmHg. According to the response, patients were divided into 3 groups: group A (LVRR+clinical response), group B (no LVRR+clinical response) and group C (no LVRR+no clinical response). The changes of NYHA classification, echocardiographic and pulmonary hemodynamic parameters were observed in the 3 groups. The Kaplan-Meier survival curve was used to analyze the differences in all-cause mortality, combined end-point events of death or re-hospitalization due to heart failure among different groups. RESULTS: A total of 45 patients with CRT implantation [aged (63.27±9.55) years, 36 males] were included. The average follow-up period was (33.76±11.50) months. Thirty-one patients (68.89%) were in group A, 9 of whom with PH. Eight patients (17.78%) were in group B, 7 of whom with PH. Six patients were in group C, all with PH. Cardiac function including NYHA classification, echocardiographic and pulmonary hemodynamic parameters had been significantly improved in group A after CRT implantation (P<0.05). In group B, NYHA classification and pulmonary hemodynamic parameters were decreased significantly (P<0.05), but echocardiographic parameters did not change obviously (P>0.05). There were no significant changes in NYHA classification, echocardiographic and pulmonary hemodynamic parameters in group C (P>0.05). Compared with group C, group A and group B had lower all-cause mortality (P=0.005) and lower incidence of composite endpoint events (P=0.001). CONCLUSIONS: Patients with LVRR and clinical response after CRT have a good prognosis. Patients with clinical response but without LVRR have a better prognosis than those without clinical response and LVRR, which may be related to the decrease of pulmonary hemodynamic parameters such as mPAP and TPG.
Subject(s)
Cardiac Resynchronization Therapy , Heart Failure/therapy , Aged , Hemodynamics , Humans , Male , Middle Aged , Pulmonary Artery , Treatment Outcome , Ventricular RemodelingABSTRACT
First-principles calculations reveal an unusual electronic state (dubbed as half excitonic insulator) in monolayer 1T-MX_{2} (M=Co, Ni and X=Cl, Br). Its one spin channel has a many-body ground state due to excitonic instability, while the other is characterized by a conventional band insulator gap. This disparity arises from a competition between the band gap and exciton binding energy, which exhibits a spin dependence due to different orbital occupations. Such a state can be identified by optical absorption measurements and angle-resolved photoemission spectroscopy. Our theory not only provides new insights for the study of exciton condensation in magnetic materials but also suggests that strongly correlated materials could be fertile candidates for excitonic insulators.
ABSTRACT
AIMS: Left bundle branch pacing (LBBP) recently emerges as a novel pacing modality. We aimed to evaluate the feasibility and cardiac synchrony of permanent LBBP in bradycardia patients. METHODS AND RESULTS: Left bundle branch pacing was successfully performed in 56 pacemaker-indicated patients with normal cardiac function. Left bundle branch pacing was achieved by penetrating the interventricular septum (IVS) into the left side sub-endocardium with the pacing lead. His-bundle pacing (HBP) was successfully performed in another 29 patients, 19 of whom had right ventricular septal pacing (RVSP) for backup pacing. The QRS duration, left ventricular (LV) activation time (LVAT), and mechanical synchrony using phase analysis of gated SPECT myocardial perfusion imaging were evaluated. Paced QRS duration in LBBP group was significantly shorter than that in RVSP group (117.8 ± 11.0 ms vs. 158.1 ± 11.1 ms, P < 0.0001) and wider than that in HBP group (99.7 ± 15.6 ms, P < 0.0001). Left bundle branch potential was recorded during procedure in 37 patients (67.3%). Left bundle branch pacing patients with potential had shorter LVAT than those without potential (73.1 ± 11.3 ms vs. 83.2 ± 16.8 ms, P = 0.03). Left bundle branch pacing patients with potential had similar LV mechanical synchrony to those in HBP group. R-wave amplitude and capture threshold of LBBP were 17.0 ± 6.7 mV and 0.5 ± 0.1 V, respectively at implant and remained stable during a mean follow-up of 4.5 months without lead-related complications. CONCLUSION: Permanent LBBP through IVS is safe and feasible in bradycardia patients. Left bundle branch pacing could achieve favourable cardiac electrical and LV mechanical synchrony.
Subject(s)
Bundle of His/physiopathology , Bundle-Branch Block/therapy , Cardiac Pacing, Artificial/methods , Electrocardiography/methods , Pacemaker, Artificial , Ventricular Function, Left/physiology , Aged , Bundle-Branch Block/diagnosis , Bundle-Branch Block/physiopathology , Echocardiography , Feasibility Studies , Female , Humans , Male , Prospective Studies , Stroke Volume , Ventricular SeptumABSTRACT
Doublesex is highly conserved and sex-specifically spliced in insect sex-determination pathways, and its alternative splicing (AS) is regulated by Transformer, an exonic splicing activator, in the model system of Drosophila melanogaster. However, due to the lack of a transformer gene, AS regulation of doublesex remains unclear in Lepidoptera, which contain the economically important silkworm Bombyx mori and thousands of agricultural pests. Here, we use yeast three-hybrid system to screen for RNA-binding proteins that recognize sex-specific exons 3 and 4 of silkworm doublesex (Bm-dsx); this approach identified BxRBP1/Lark binding to the exon 3, and BxRBP2/TBPH and BxRBP3/Aret binding to the exon 4. Investigation of tissues shows that BxRBP1 and BxRBP2 have no sex specificity, but BxRBP3 has - three of its four isoforms are expressed with a sex-bias. Using novel sex-specific silkworm cell lines, we find that BxRBP1 and BxRBP3 directly interact with each other, and cooperatively function as splicing repressors. Over-expression of BxRBP1 and BxRBP3 isoforms efficiently inhibits splicing of the exons 3 and 4 in the female-specific cells and generates the male-specific isoform of Bm-dsx. We also demonstrate that the sex-determination upstream gene Masc regulates alternatively transcribed BxRBP3 isoforms. Thus, we identify a new regulatory mechanism of doublesex AS in the silkworm, revealing an evolutionary divergence in insect sex-determination.