Outcomes of Mitral Valve Repair for Posterior Leaflet Prolapse, Anterior Leaflet Prolapse, and Bileaflet Prolapse.

Background: Mitral valve repair (MVr) is an effective treatment for degenerative mitral regurgitation (DMR).And the outcomes and repair rates for posterior leaflet prolapse (PLP), anterior leaflet prolapse (ALP), and bileaflet prolapse (BLP) vary. This study aimed to compare the outcomes of mitral valve repair for patients with PLP, ALP, and BLP. Methods: From 2010 to 2019, 1192 patients with degenerative mitral valve regurgitation underwent surgery at our hospital. And 1069 patients were identified. The average age of all patients was (54.74 ± 12.17) years old for all patients. 273 patients (25.5%) had ALP, 148 patients (13.8%) had BLP, and 648 patients (60.6%) had PLP. All patients were followed up for an average duration of 5.1 years. We compared the outcomes of patients with ALP, PLP, and BLP. Results: Patients with ALP were the youngest of the 3 groups and had the highest prevalence of atrial fibrillation. Patients with PLP had the highest prevalence of hypertension, whereas patients with BLP and ALP had larger left ventricular end-diastolic and left ventricular end-systolic diameters. ALP and BLP repairs had a longer cardiopulmonary bypass and aortic cross-clamp time.10 patients dead in-hospital, 5 patients had PLP, 3 had ALP, and 2 had BLP. The 10-year survival cumulative incidences of reoperation among ALP, BLP, and PLP repairs were not significantly different. ALP repair still had higher cumulative incidences of recurrent mitral regurgitation (MR) compared to PLP. Conclusions: The rates of long-term survival and freedom from reoperation were not significantly different among patients with ALP, BLP, and PLP. ALP repair has higher cumulative incidences of recurrent MR compared to PLP.

Impacts of Left Atrial Appendage Treatments on Mitral Valve Diseases during Surgical Ablations.

Background: Left atrial appendages (LAAs) play an important role in regulating left atrial function, and much evidence supports the possibility that changes in left atrial structure may cause or worsen mitral regurgitation. This study intended to investigate the outcomes of patients with mitral regurgitation who underwent left atrial appendage closure (resection or endocardial closure) during isolated surgical ablations. Methods: Patients with mild or moderate mitral regurgitation who received isolated surgical ablations for atrial fibrillation (AF) in our center from 2013 to 2022 were referred. During follow-up, each clinical visit was composed of medical interrogation, a 24 h Holter, and echocardiographic evaluation. Death, atrial fibrillation, worsening of mitral regurgitation, and stroke were evaluated as outcomes. Freedom from outcomes whose results were adjusted by inverse probability of treatment weighting for causal effects after acquiring propensity scores. Results: A total of 456 patients were enrolled in this study. During a median follow-up of 48 months, 30 deaths and 11 cases of stroke were observed. After adjustments, no significant differences in terms of death or stroke were observed among the three groups. Patients who underwent resection or endocardial closure during surgical ablations had a higher risk of mitral regurgitation worsening during follow-up (p < 0.05). During the whole follow-up, patients who underwent left atrial appendage interventions showed significantly larger left atrial and mitral annular diameters, as well as lower tethering height than those who had left atrial appendage preserved (all p < 0.05). Conclusions: Mitral regurgitation was more likely to get worse when patients with fundamental mitral diseases underwent LAA interventions during isolated surgical AF ablations. In the absence of LAA, the dilation of the left atrium and mitral annulus may ultimately lead to worsening of regurgitation.

Study on fluid inclusions and stable isotopics of W-Mo ore deposits in the Ningshan-Zhen'an area, South Qinling, China.

The study of the fluid inclusions of W-Mo deposits in the mineralization area of Ningshan-Zhen'an , Shaanxi Province, China shows that the gas-liquid two-phase inclusions are mainly present in W-Mo deposits, and the ore-forming fluid can be divided into four types: high-temperature type, middle-high-temperature type, middle-temperature type and low-temperature type. The formation depths of the W-Mo mineralization range from 4.2 to 8.4 km. The boiling and mixing of fluid may have been important mechanisms for the formation of W-Mo mineralization. The skarn-type mineralization is dominated by magmatic water, the quartz-vein-type mineralization includes both magmatic water and meteoric water, and the meteoric water is more involved in the quartz-fluorite-vein-type, beryl-quartz-vein-type and pegmatite-type mineralization. Magma is the main source of sulfur; that is, magma is the main source of mineralization. Combined with the metallogenic setting and geological characteristics of typical ore deposits, in the process of structural system transformation in South Qinling, the ore-forming magma fluid in the Late Indosinian-Yanshanian period was uplifted and emplaced along the NW-WNW direction and NE-NNE direction, and eventually, NW-WNW fault-controlled skarn-type W-Mo mineralization and quartz-vein-type W-Mo deposits accompanied by greisenization, albitization and potash feldspathization formed.

DDAH-1 maintains endoplasmic reticulum-mitochondria contacts and protects dopaminergic neurons in Parkinson's disease.

The loss of dopaminergic neurons in the substantia nigra is a hallmark of pathology in Parkinson's disease (PD). Dimethylarginine dimethylaminohydrolase-1 (DDAH-1) is the critical enzyme responsible for the degradation of asymmetric dimethylarginine (ADMA) which inhibits nitric oxide (NO) synthase and has been implicated in neurodegeneration. Mitochondrial dysfunction, particularly in the mitochondria-associated endoplasmic reticulum membrane (MAM), plays a critical role in this process, although the specific molecular target has not yet been determined. This study aims to examine the involvement of DDAH-1 in the nigrostriatal dopaminergic pathway and PD pathogenesis. The distribution of DDAH-1 in the brain and its colocalization with dopaminergic neurons were observed. The loss of dopaminergic neurons and aggravated locomotor disability after rotenone (ROT) injection were showed in the DDAH-1 knockout rat. L-arginine (ARG) and NO donors were employed to elucidate the role of NO respectively. In vitro, we investigated the effects of DDAH-1 knockdown or overexpression on cell viability and mitochondrial functions, as well as modulation of ADMA/NO levels using ADMA or ARG. MAM formation was assessed by the Mitofusin2 oligomerization and the mitochondrial ubiquitin ligase (MITOL) phosphorylation. We found that DDAH-1 downregulation resulted in enhanced cell death and mitochondrial dysfunctions, accompanied by elevated ADMA and reduced NO levels. However, the recovered NO level after the ARG supplement failed to exhibit a protective effect on mitochondrial functions and partially restored cell viability. DDAH-1 overexpression prevented ROT toxicity, while ADMA treatment attenuated these protective effects. The declines of MAM formation in ROT-treated cells were exacerbated by DDAH-1 downregulation via reduced MITOL phosphorylation, which was reversed by DDAH-1 overexpression. Together, the abundant expression of DDAH-1 in nigral dopaminergic neurons may exert neuroprotective effects by maintaining MAM formation and mitochondrial function probably via ADMA, indicating the therapeutic potential of targeting DDAH-1 for PD.

Establishment of a prognostic model for hypoxia-associated genes in OPSCC and revelation of intercellular crosstalk.

Hypoxia exerts a profound influence on the tumor microenvironment and immune response, shaping treatment outcomes and prognosis. Utilizing consistency clustering, we discerned two hypoxia subtypes in OPSCC bulk sequencing data from GEO. Key modules within OPSCC were identified through weighted gene correlation network analysis (WGCNA). Core modules underwent CIBERSORT immune infiltration analysis and GSEA functional enrichment. Univariate Cox and LASSO analyses were employed to construct prognostic models for seven hypoxia-related genes. Further investigation into clinical characteristics, the immune microenvironment, and TIDE algorithm prediction for immunotherapy response was conducted in high- and low-risk groups. scRNA-seq data were visually represented through TSNE clustering, employing the scissors algorithm to map hypoxia phenotypes. Interactions among cellular subpopulations were explored using the Cellchat package, with additional assessments of metabolic and transcriptional activities. Integration with clinical data unveiled a prevalence of HPV-positive patients in the low hypoxia and low-risk groups. Immunohistochemical validation demonstrated low TDO2 expression in HPV-positive (P16-positive) patients. Our prediction suggested that HPV16 E7 promotes HIF-1α inhibition, leading to reduced glycolytic activity, ultimately contributing to better prognosis and treatment sensitivity. The scissors algorithm effectively segregated epithelial cells and fibroblasts into distinct clusters based on hypoxia characteristics. Cellular communication analysis illuminated significant crosstalk among hypoxia-associated epithelial, fibroblast, and endothelial cells, potentially fostering tumor proliferation and metastasis.

Gene expression regulation of the effect of shading on chlorophyll content in Fuding White Tea (Camellia sinensis L.).

Shading is an important practical method to improve the quality of green tea. Previous research of our group found that because the biosynthesis and distribution of theanine in tea plants were affected by down regulation of gene encoding amino acid permeases, theanine content in tea leaves which grown under shading condition was significantly higher than those under natural light. In this study, our group analyzed the changes of tea leaf area, free amino acid content and photosynthetic parameters under natural light and shading conditions, to ensure that moderate shading did not reduce but improve the quality of tea. Transcriptome sequencing and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis were conducted to reveal the expression levels of genes related to chlorophyll content and chlorophyll a/b ratio under natural light and shading conditions. Experimental results revealed the presence of the following differentially expressed genes (DEGs) in the porphyrin and chlorophyll metabolism pathway of tea under natural light and shading conditions: the up regulation of CPOX expression may lead to an increase in the accumulation of raw materials of chlorophyll synthesis, while the down regulation of SGR expression may lead to a decrease in chlorophyll degradation. The combined effect of these two genes may lead to an increase in the total chlorophyll content of tea. The down regulation of NOL expression may lead to the obstruction of chlorophyll b transform to chlorophyll a, that is, the decrease of the chlorophyll a/b ratio. This study investigated the molecular mechanism of chlorophyll content and component alteration in Fuding white tea under natural light and shading conditions, and elucidated the effects of different light intensities on the porphyrin and chlorophyll metabolism pathway of tea. Thus provided deep understanding of chlorophyll regulation under shading condition in tea cultivation, which could contribute to high-quality matcha production.

Cardiac magnetic resonance feature tracking derived left atrial strain in the diagnosis of patients with constrictive pericarditis and restrictive cardiomyopathy.

Objective: To explore the diagnostic value of cardiac magnetic resonance feature tracking (CMR-FT) divided left atrial (LA) strain in differentiating constrictive pericarditis (CP) and restrictive cardiomyopathy (RCM). Methods: Patients with CP (n = 40) and RCM (n = 40), and another 40 normal control group were retrospectively enrolled over a period of 8 years at a tertiary cardiac centre. Left ventricular (LV) and biatrial strain and strain rate (SR) were measured. Atrial strain was used to differentiate between patients with CP and RCM. Then, patients were grouped according to their left ventricular ejection fraction (LVEF), either ≥50% or < 50%. A deeper analysis was done to evaluate the diagnostic value of atrial strain in these subgroups. Receiver operating characteristic curves (ROC) were used to assess the accuracy of myocardial strain based on CMR FT for the differential diagnosis of CP and RCM. Results: LV and LA strain and SR were significantly lower in patients with CP and RCM than those in the normal controls (P < 0.05). LA strain and SR were significantly lower in the RCM group than in the CP group (P < 0.05). In patients with either LVEF≥50% or＜50%, LA strain were lower in the RCM group than in the CP group (P < 0.05). ROC analysis showed that LA stored strain (LA-εs) had a good differential diagnostic value for CP and RCM, with an area under the curve (AUC) of 0.811 and an optimal cutoff value of 6.98%, above this value it tends to develop CP. Further, an excellent differential diagnostic value was found in patients with LVEF＜50%, with an AUC of 0.955. Conclusion: LA strain analysis obtained by CMR-FT provides good differential diagnostic value for distinguishing CP from RCM, especially in patients with LVEF＜50%.

Characterization of the Binding Properties of Ten Aptamers Using the Intrinsic Fluorescence of Oxytetracycline.

Tetracyclines are a class of commonly used four-ringed antibiotics. A series of DNA aptamers were recently obtained using the capture-SELEX (systematic evolution of ligands by exponential enrichment) method to bind to oxytetracycline, and one of the aptamers can bind to a few other tetracycline antibiotics as well. Upon binding to the aptamers, the intrinsic fluorescence of tetracycline antibiotics can be enhanced. At least 10 different DNA aptamers were isolated from the previous selection experiment. In this work, a systematic characterization of these ten aptamers was performed. Each of these aptamers shows a different degree of fluorescence enhancement ranging from around 1-fold to over 20-fold. Fluorescence enhancement was boosted in the presence of Mg2+. Isothermal titration calorimetry (ITC) studies were done and showed a great variety in dissociation constant (Kd) from 62 nM to 1.6 µM. Steady-state fluorescence spectroscopy and fluorescence lifetime studies showed a correlation between fluorescence lifetime and degree of fluorescence enhancement. A few aptamers showed slow binding kinetics, although no correlation was found between the kinetics of fluorescence change and degree of fluorescence enhancement. This is the first study of ten different aptamers for the same target, providing fundamental insights into aptamer binding and bioanalytical applications.

Topology-Optimized Splints vs Casts for Distal Radius Fractures: A Randomized Clinical Trial.

Importance: To date, there is currently no evidence-based medical support for the efficacy of topology-optimized splints in treating distal radius fractures. Objective: To assess the clinical efficacy and complication rates of topology-optimized splints in the treatment of distal radius fractures after closed manual reduction. Design, Setting, and Participants: This 12-week, multicenter, open-label, analyst-blinded randomized clinical trial (comprising a 6-week intervention followed by a 6-week observational phase) was carried out from December 3, 2021, to March 10, 2023, among 110 participants with distal radius fractures. Statistical analysis was performed on an intention-to-treat basis between June 3 and 30, 2023. Intervention: Participants were randomly assigned to 2 groups: the intervention group received topology-optimized splint immobilization and the control group received cast immobilization after closed manual reduction for 6weeks. After this period, immobilization was removed, and wrist rehabilitation activities commenced. Main Outcomes and Measures: The primary outcome was the Gartland-Werley (G-W) wrist score at 6 weeks (where higher scores indicate more severe wrist dysfunction). Secondary outcomes encompassed radiographic parameters, visual analog scale scores, swelling degree grade, complication rates, and 3 dimensions of G-W wrist scores. Results: A total of 110 patients (mean [SD] age, 64.1 [12.7] years; 89 women [81%]) enrolled in the clinical trial, and complete outcome measurements were obtained for 101 patients (92%). Median G-W scores at 6 weeks were 15 (IQR, 13-18) for the splint group and 17 (IQR, 13-18) for the cast group (mean difference, -2.0 [95% CI, -3.4 to -0.6]; P = .03), indicating a statistically significant advantage for the splint group. At 12 weeks, no clinically significant differences in G-W scores between the 2 groups were observed. Complication rates, including shoulder-elbow pain and dysfunction and skin irritation, were less common in the splint group (shoulder-elbow pain and dysfunction: risk ratio, 0.28 [95% CI, 0.08-0.93]; P = .03; skin irritation: risk ratio, 0.30 [95% CI, 0.10-0.89]; P = .02). Conclusions and Relevance: Findings of this randomized clinical trial suggest that patients with distal radius fractures that were managed with topology-optimized splints had better wrist functional outcomes and fewer complications at 6 weeks compared with those who received casting, with no difference at week 12. Therefore, topology-optimized splints with improved performance have the potential to be an advisable approach in the management of distal radius fractures. Trial Registration: Chinese Clinical Trial Registry: ChiCTR2000036480.

Alisol B 23-acetate promotes white adipose tissue browning to mitigate high-fat diet-induced obesity by regulating mTOR-SREBP1 signaling.

OBJECTIVE: Obesity is a global health concern with management strategies encompassing bariatric surgery and anti-obesity drugs; however, concerns regarding complexities and side effects persist, driving research for more effective, low-risk strategies. The promotion of white adipose tissue (WAT) browning has emerged as a promising approach. Moreover, alisol B 23-acetate (AB23A) has demonstrated efficacy in addressing metabolic disorders, suggesting its potential as a therapeutic agent in obesity management. Therefore, in this study, we aimed to investigate the therapeutic potential of AB23A for mitigating obesity by regulating metabolic phenotypes and lipid distribution in mice fed a high-fat diet (HFD). METHODS: An obesity mouse model was established by administration of an HFD. Glucose and insulin metabolism were assessed via glucose and insulin tolerance tests. Adipocyte size was determined using hematoxylin and eosin staining. The expression of browning markers in WAT was evaluated using Western blotting and quantitative real-time polymerase chain reaction. Metabolic cage monitoring involved the assessment of various parameters, including food and water intake, energy metabolism, respiratory exchange rates, and physical activity. Moreover, oil red O staining was used to evaluate intracellular lipid accumulation. A bioinformatic analysis tool for identifying the molecular mechanisms of traditional Chinese medicine was used to examine AB23A targets and associated signaling pathways. RESULTS: AB23A administration significantly reduced the weight of obese mice, decreased the mass of inguinal WAT, epididymal WAT, and perirenal adipose tissue, improved glucose and insulin metabolism, and reduced adipocyte size. Moreover, treatment with AB23A promoted the expression of browning markers in WAT, enhanced overall energy metabolism in mice, and had no discernible effect on food intake, water consumption, or physical activity. In 3T3-L1 cells, AB23A inhibited lipid accumulation, and both AB23A and rapamycin inhibited the mammalian target of rapamycin-sterol regulatory element-binding protein-1 (mTOR-SREBP1) signaling pathway. Furthermore, 3-isobutyl-1-methylxanthine, dexamethasone and insulin, at concentrations of 0.25 mmol/L, 0.25 µmol/L and 1 µg/mL, respectively, induced activation of the mTOR-SREBP1 signaling pathway, which was further strengthened by an mTOR activator MHY1485. Notably, MHY1485 reversed the beneficial effects of AB23A in 3T3-L1 cells. CONCLUSION: AB23A promoted WAT browning by inhibiting the mTOR-SREBP1 signaling pathway, offering a potential strategy to prevent obesity. Please cite this article as: Han LL, Zhang X, Zhang H, Li T, Zhao YC, Tian MH, Sun FL, Feng B. Alisol B 23-acetate promotes white adipose tissue browning to mitigate high-fat diet-induced obesity by regulating mTOR-SREBP1 signaling. J Integr Med. 2024; 22(1): 83-92.

Phillygenin prevents osteoclast differentiation and bone loss by targeting RhoA.

Forsythia suspensa tea is a popular traditional Chinese medicine decoction for its healthy and therapeutic benefits. However, its effects in bone metabolism were not clear. In recent study, we uncovered anti-osteoclastogenesis property of Phillygenin (Phi), a compound abundant in Forsythia suspensa leaves, and aimed to investigate the effect and mechanism of Phi on bone metabolism in vivo and in vitro. Lipopolysaccharides-induced murine calvaria osteolysis and ovariectomy-induced bone loss animal models were used to identify the bone-protective effect of Phi in vivo and micro-CT, pQCT, and TRAP staining were applied. We used CCK8, TUNEL, BrdU, and TRAP staining to evaluate the efficacy of Phi on the proliferation and formation of OCs in primary mBMMs. RNA sequence, activity-based protein profiling, molecular docking, G-LISA, and WB were used to inspect the target and underlying mechanism of Phi's actions in mBMMs. We found Phi significantly inhibited bone resorption in vivo and inhibited mBMMs osteoclastogenesis in vitro. Ras homolog gene family member A (RhoA) was identified as the direct target of Phi. It counteracted the effects of RhoA activator and acted as a RhoA inhibitor. By targeting RhoA, Phi modulated Rho-associated coiled-coil containing protein kinase 1 (ROCK1) activity and regulated its downstream NF-κB/NFATc1/c-fos pathway. Furthermore, Phi depressed the disassembling of F-actin ring through cofilin and myosin1a. Our findings provided Phi as a potential option for treating bone loss diseases by targeting RhoA and highlighted the importance of F. suspensa as a preventive approach in bone disorders.

Global prevalence of Plasmodium infection in wild birds: A systematic review and meta-analysis.

Avian malaria is a vector-borne parasitic disease caused by Plasmodium infection transmitted to birds by mosquitoes. The aim of this systematic review was to analyze the global prevalence of malaria and risk factors associated with infection in wild birds. A systematic search of the databases CNKI, WanFang, VIP, PubMed, and ScienceDirect was performed from database inception to 24 February 2023. The search identified 3181 retrieved articles, of which 52 articles met predetermined inclusion criteria. Meta-analysis was performed using the random-effects model. The estimated pooled global prevalence of Plasmodium infection in wild birds was 16%. Sub-group analysis showed that the highest prevalence was associated with adult birds, migrant birds, North America, tropical rainforest climate, birds captured by mist nets, detection of infection by microscopy, medium quality studies, and studies published after 2016. Our study highlights the need for more understanding of Plasmodium prevalence in wild birds and identifying risk factors associated with infection to inform future infection control measures.

Longitudinal Assessment of Pharmacy Students' Collaborative Practice Abilities.

OBJECTIVE: Interprofessional education (IPE) varies across schools/colleges of pharmacy. Long-term impact of IPE on interprofessional collaborative competencies remains uncertain despite available data on singular experiences. This study aimed to evaluate changes in pharmacy students' collaborative abilities over the second and third professional years (PYs). METHODS: Students completed the Interprofessional Collaborative Competency Attainment Scale - Revised (ICCAS-R) after 2 large-scale interprofessional forums that occurred approximately 8 months apart. Four cohorts of students were used to examine the longitudinal change in collaborative abilities: cohort 1 (2019), cohort 2 (2020), cohort 3 (2021) and cohort 4 (2022). The ICCAS-R was used to capture data from 4 timepoints for each student in each cohort: prior to the Spring Forum in PY2 (T1), after the Spring Forum in PY2 (T2), prior to the Fall Forum in PY3 (T3), and after the Fall Forum in PY3 (T4). Using repeated measures analysis of variance, 4 total mean scores (T1 = pre1, T2 = post1, T3 = pre2, T4 = post2) were compared. RESULTS: Four cohorts (N = 414) completed the interprofessional forums and 336 (81%) completed the ICCAS-R instrument and were included. In each cohort, total mean scores increased T1 to T2 and T3 to T4, indicating an increase in self-assessed abilities pre/post-forum. Total mean scores decreased between T2 and T3, indicating that collaborative abilities decreased during the period between interprofessional forums. CONCLUSION: While students' collaborative abilities increased around the time of the forum experiences, these changes decreased in between experiences. These findings suggest that interprofessional competencies should be reinforced at multiple time points to support enduring effects.

Outcomes of Mitral Valve Repair for Degenerative Mitral Disease: A Single-Centre 10-Year Experience.

OBJECTIVE: To evaluate the long-term outcomes of degenerative mitral valve (MV) repair. METHODS: This study analysed 1,069 patients who underwent MV repair due to degenerative MV disease at Beijing Anzhen Hospital from January 2010 to December 2019. All patients were clinically followed until December 2019, with an average follow-up period of 4.7 years. Perioperative complications, 30-day mortality, long-term outcomes, and risk factors of all-cause death and recurrent mitral regurgitation (MR) were summarised. RESULTS: Ten patients died in the hospital and 33 died during the follow-up period. Recurrent MR occurred in 113 patients. Fourteen patients underwent re-operation. Rates of long-term survival, absence of recurrent MR, and no re-operation were 94.0% (91.6%-96.6%), 81.2% (77.3%-85.3%), and 98.2% (97.2%-99.3%), respectively. The risk factors for long-term all-cause death included age and an ejection fraction (EF) <60%. The risk factors for recurrent MR included age, female sex, E-wave velocity, anterior prolapse, residual 1+MR postoperatively, and lower body mass index. CONCLUSIONS: Mitral valve repair is an effective treatment for degenerative MV disease that, in an experienced heart centre, can be performed with low mortality, recurrence, and re-operation rates. Advanced age and an EF <60% were risk factors for long-term all-cause death. Age, female sex, residual 1+MR postoperatively, lower body mass index, higher peak E-wave velocity, and anterior prolapse were risk factors for recurrent MR.

Effects of blister blight disease on endophytic microbial diversity and community structure in tea (Camellia sinensis) leaves.

In this study, metagenomic sequencing technology was employed to analyze the ITS1 region sequence of the ITS rDNA gene of endophytic fungi and 16S sequence of endophytic bacteria in tea leaves with varying degrees of infection by tea blister blight disease as well as healthy tea leaves. Subsequently, a comparative analysis was conducted on the endophytic microbial diversity and the community structure in tea leaves. The findings of this investigation reveal a shift in the dominant endophytic fungal genera from Ascomycota to Basidiomycota as the disease progressed. Furthermore, a negative correlation was observed between Exobasidium and Talaromyce, with Talaromyce exhibiting potential as an antagonist against the disease. Meanwhile, our findings reveal that Proteobacteria, Firmicutes, and Actinobacteria were the three most abundant bacteria phyla in tea leaves. As the disease progressed, there was an increase in the relative abundance of Actinobacteria, while Variovorax, Sphingomonas, and Pseudomonas were found to have higher abundance in later stages. The diversity analysis results indicated that the endophytic microbial diversity and the community structure in tea leaves in the diseased group were lower than those in the healthy control group. In general, blister blight disease altered the community structure of endophytic microorganisms in tea leaves, resulting in a few species with high abundance. The study lays a foundation for investigating the pathogenic mechanism of tea blister disease and establishing a theoretical basis for controlling diseases in tea trees.

External application of brassinolide enhances cold resistance of tea plants (Camellia sinensis L.) by integrating calcium signals.

MAIN CONCLUSION: Exogenous brassinolide can activate the expression of key genes in the calcium signalling pathway to enhance cold resistance of tea plants. Brassinolide is an endogenous sterol phytohormone containing multiple hydroxyl groups that has the important function of improving plant cold resistance and alleviating freeze damage. To explore the molecular mechanism of how brassinolide improves the cold resistance of tea plants, "Qiancha 1" was used as the material, and the method of spraying brassinolide on the leaves was adopted to explore its effects on the tea plants under 4 °C low-temperature treatment. The results showed that brassinolide can significantly increase the protective enzyme activity of tea plants under cold stress and reduce cold damage. At the transcriptome level, brassinolide significantly enhanced the expression of key genes involved in calcium signal transduction, Calmodulin (CaM), Calcium-dependent protein kinase (CDPK), calcineurin B-like protein (CBL) and calmodulin-binding transcriptional activators (CAMTA), which then activated the downstream key genes transcriptional regulator CBF1 (CBF1) and transcription factor ICE1 (ICE1) during cold induction. Quantitative real-time PCR (qRT‒PCR) results showed that the expression of these genes was significantly induced after treatment with brassinolide, especially CaM and CBF1. When calcium signalling was inhibited, the upregulated expression of CBF1 and ICE1 disappeared, and when CAMTA was knocked down, the expression of other genes under cold stress was also significantly reduced. The above results indicate that brassinolide combined with the calcium signalling pathway can improve the cold resistance of tea plants. This study provides a new theoretical basis for the study of the cold resistance mechanism of brassinolide.

Transcriptome analysis reveals the effect of acidic environment on adventitious root differentiation in Camellia sinensis.

The generation of adventitious roots (ARs) is the key to the success of cuttings. The appropriate environment for AR differentiation in tea plants is acidic. However, the mechanism is unclear. In this study, pH 4.5 was suitable condition for the differentiation of AR in tea plants. At the base of cuttings, the root primordia differentiated ARs more rapidly at pH 4.5 than pH 7.0, and nine AR differentiation-related genes were found to be differentially expressed in 30 days, the result was also validated by qRT-PCR. The promoter regions of these genes contained auxin and brassinosteroid response elements. The expression levels of several genes which were involved in auxin and brassinosteroid synthesis as well as signaling at pH 4.5 compared to pH 7.0 occurred differential expression. Brassinolide (BL) and indole-3-acetic acid (IAA) could affect the differentiation of ARs under pH 4.5 and pH 7.0. By qRT-PCR analysis of genes during ARs generation, BL and IAA inhibited and promoted the expression of CsIAA14 gene, respectively, to regulate auxin signal transduction. Meanwhile, the expression levels of CsKNAT4, CsNAC2, CsNAC100, CsWRKY30 and CsLBD18 genes were up-regulated upon auxin treatment and were positively correlated with ARs differentiation.This study showed that pH 4.5 was the most suitable environment for the root primordia differentiation of AR in tea plant. Proper acidic pH conditions promoted auxin synthesis and signal transduction. The auxin initiated the expression of AR differentiation-related genes, and promoted its differentiated. BL was involved in ARs formation and elongation by regulating auxin signal transduction.

Light-up split aptamers: binding thermodynamics and kinetics for sensing.

Due to their programmable structures, many aptamers can be readily split into two halves while still retaining their target binding function. While split aptamers are prevalent in the biosensor field, fundamental studies of their binding are still lacking. In this work, we took advantage of the fluorescence enhancement property of a new aptamer named OTC5 that can bind to tetracycline antibiotics to compare various split aptamers with the full-length aptamer. The split aptamers were designed to have different stem lengths. Longer stem length aptamers showed similar dissociation constants (Kd) to the full-length aptamer, while a shorter stem construct showed an 85-fold increase in Kd. Temperature-dependent fluorescence measurements confirmed the lower thermostability of split aptamers. Isothermal titration calorimetry indicated that split aptamer binding can release more heat but have an even larger entropy loss. Finally, a colorimetric biosensor using gold nanoparticles was designed by pre-assembling two thiolated aptamer halves, which can then link gold nanoparticles to give a red-to-blue color change.

Capture-SELEX for Chloramphenicol Binding Aptamers for Labeled and Label-Free Fluorescence Sensing.

Chloramphenicol (CAP) is a potent antibiotic. Due to its side effects, CAP is currently banned in most countries, but it is still found in many food products and in the environment. Developing aptamer-based biosensors for the detection of CAP has interested many researchers. While both RNA and DNA aptamers were previously reported for CAP, they were all obtained by immobilization of the CAP base, which omitted the two chlorine atoms. In this work, DNA aptamers were selected using the library-immobilized method and free unmodified CAP. Three families of aptamers were obtained, and the best one named CAP1 showed a dissociation constant (Kd) of 9.8 µM using isothermal titration calorimetry (ITC). A fluorescent strand-displacement sensor showed a limit of detection (LOD) of 14 µM CAP. Thioflavin T (ThT) staining allowed label-free detection of CAP with a LOD of 1 µM in buffer, 1.8 µM in Lake Ontario water, and 3.6 µM in a wastewater sample. Comparisons were made with previously reported aptamers, and ITC failed to show binding of a previously reported 80-mer aptamer. Due to the small size and well-defined secondary structures of CAP1, this aptamer will find analytical applications for environmental and food monitoring.

Outcome of mitral repair combined with Cox-maze procedure for atrial functional mitral regurgitation with heart failure with recovered ejection fraction.

OBJECTIVES: Atrial functional mitral regurgitation (AFMR) in patients with heart failure with recovered ejection fraction has received insufficient attention. This study analysed the prognosis and outcomes of mitral valve (MV) repair combined with the Cox-maze procedure. METHODS: A prospective cohort study of patients with AFMR with left ventricular ejection fraction (LVEF) <40% was conducted. All patients received guideline-directed medical therapy. Those with recovered ejection fraction underwent MV repair combined with the Cox-maze procedure. Mortality, atrial fibrillation (AF) recurrence, mitral regurgitation (MR) and postoperative tricuspid regurgitation were assessed using the inverse probability weighting (IPW) method. RESULTS: In total, 312 patients were enrolled in this study between 2010 and 2019, 247 of whom underwent MV repair combined with the Cox-maze procedure [full recovery (LVEF > 50%): n = 132, partial recovery (LVEF of 40-50%): n = 115]. IPW-adjusted survival of patients with LVEF ≥50% and LVEF 40-50% showed no significant difference [hazard ratio (HR): 2.18, 95% confidence interval: 0.46-10.38, P = 0.33]. However, patients with LVEF ≥50% had better IPW-adjusted long-term freedom from recurrent MR [HR: 2.44 (1.28-4.63), P = 0.0065] and AF recurrence [HR: 1.85 (1.06-3.21), P = 0.030] than those with LVEF of 40-50%. CONCLUSIONS: MV repair combined with the Cox-maze procedure was effective and feasible in patients with severe AFMR with heart failure with recovered ejection fraction. Additionally, patients with LVEF ≥50% after guideline-directed medical therapy undergoing these combined procedures had better long-term freedom from recurrent AF and MR than those with LVEF of 40-50%.