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Ovarian cancer (OC) is the fifth most common cause of death in women worldwide. Chemoresistance is a key reason for treatment failure, causing high mortality. As a member of the tripartite motif-containing (TRIM) protein family, tripartite motif 47 (TRIM47) plays a vital role in the carcinogenesis and drug resistance of various cancers. This study investigated the impact and mechanisms of TRIM47 on cisplatin (DDP) chemosensitivity and apoptosis in OC. OC cell viability was assessed with a cell counting kit-8 assay and OC cell apoptosis was assessed using flow cytometry, caspase-3 and caspase-9 activity, and Bax and Bcl-2 expression assays while gene and protein expression were assessed using qRT-PCR and Western blot assays. The expression of TRIM47 was significantly increased in both DDP-resistant tissues from patients with OC tissues and in cancer cell lines compared with that in normal tissue or parental cell lines. The increased level of TRIM47 correlated with poor prognosis in patients with OC. Functional assays demonstrated that TRIM47 promoted DDP resistance both in vitro and in vivo. The increased viability and reduced apoptosis of OC cells induced by TRIM47 can be rescued by the endoplasmic reticulum (ER) stress-inducer tunicamycin, suggesting that TRIM47 inhibits OC cell apoptosis by suppressing ER stress. Therefore, TRIM47 may be targeted as a therapeutic strategy for DDP resistance in OC.
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The market demand for essential oil containing citral is increasing. Our research group identified a rare chemotype of Camphora officinarum whose leaves are high in citral content by examining over 1000 wild trees across the entire native distribution area of C. officinarum in China. Because C. officinarum is suitable for large-scale cultivation, it is therefore seen as a promising source of natural citral. However, the molecular mechanism of citral biosynthesis in C. officinarum is poorly understood. In this study, transcriptomic analyses of C. officinarum with different citral contents revealed a strong positive correlation between the expression of a putative geraniol synthase gene (CoGES) and citral content. The CoGES cDNA was cloned, and the CoGES protein shared high similarity with other monoterpene synthases. Enzymatic assays of CoGES with geranyl diphosphate (GPP) as substrate yielded geraniol as the single product, which is the precursor of citral. Further transient expression of CoGES in Nicotiana benthamiana resulted in a higher relative content of geranial and the appearance of a new substance, neral. These findings indicate that CoGES is a geraniol synthase-encoding gene, and the encoded protein can catalyze the transformation of GPP into geraniol, which is further converted into geranial and neral through an unknown mechanism in vivo. These findings expand our understanding of citral biosynthesis in Lauraceae plants. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-024-01463-4.
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The fruits of Alpinia oxyphylla has been used a famous traditional Chinese medicine. A chemical investigation on the fruits of A. oxyphylla resulted in the isolation of one new acetylated flavanol glucuronide (1) and two known compounds (2-3). Compound 1 displayed a weak inhibitory effect on U251 cells with the IC50 value 128.51 µM while the positive control drug temozolomide exhibited the IC50 value 35.37 µM.
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Ovarian cancer is a common gynecological malignancy, and its treatment remains challenging. Although ovarian cancer may respond to immunotherapy because of endogenous immunity at the molecular or T cell level, immunotherapy has so far not had the desired effect. The functional status of preexisting T cells is an indispensable determinant of powerful antitumor immunity and immunotherapy. T cell exhaustion and senescence are two crucial states of T cell dysfunction, which share some overlapping phenotypic and functional features, but each status possesses unique molecular and developmental signatures. It has been widely accepted that exhaustion and senescence of T cells are important strategies for cancer cells to evade immunosurveillance and maintain the immunosuppressive microenvironment. Herein, this review summarizes the phenotypic and functional features of exhaust and senescent T cells, and describes the key drivers of the two T cell dysfunctional states in the tumor microenvironment and their functional roles in ovarian cancer. Furthermore, we present a summary of the molecular machinery and signaling pathways governing T cell exhaustion and senescence. Possible strategies that can prevent and/or reverse T cell dysfunction are also explored. An in-depth understanding of exhausted and senescent T cells will provide novel strategies to enhance immunotherapy of ovarian cancer through redirecting tumor-specific T cells away from a dysfunctional developmental trajectory.
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Aims/Background Although electromyography has been extensively used in the diagnosis of neurological diseases, there is no comprehensive understanding of the electromyography manifestations of spinal dural arteriovenous fistula. Given the widespread use of electromyography in the diagnosis of neurological conditions, it is worthwhile to holistically analyse the electromyography findings of spinal dural arteriovenous fistula to differentiate it from neurological diseases that share similar clinical manifestations. The aim of this study is to evaluate whether electromyography can distinguish spinal dural arteriovenous fistula from longitudinally extensive transverse myelitis. Methods We holistically reviewed files of all patients who were diagnosed with spinal dural arteriovenous fistula or longitudinally extensive transverse myelitis at The First Medical Centre of PLA General Hospital from 1 January 2010 to 31 December 2020. We compared the symptomology, epidemiology, and imaging results of patients with spinal dural arteriovenous fistula and longitudinally extensive transverse myelitis, placing emphasis on their electromyography manifestations. Student's t test was used to analyse normally distributed data, while Chi-square test was used to compare classification statistics. Results Lesions of spinal dural arteriovenous fistula shown on images tend to appear at lower lumbar and sacral segments, whereas lesions of the cervical and upper thoracic segments are more characteristic of longitudinally extensive transverse myelitis. Spinal dural arteriovenous fistula patients and longitudinally extensive transverse myelitis patients overlap in terms of clinical manifestations. After comparison, the two groups of patients had different demographics (age, sex), onset mode, predisposing factors before onset, and electromyographic features. The electromyographic features of patients with spinal dural arteriovenous fistula were associated with neurogenic damage (p < 0.001). Conclusions In patients with spinal dural arteriovenous fistula, electromyography can help clinicians to identify early disease, avoid patient treatment delay, and eliminate unnecessary treatment.
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Malformações Vasculares do Sistema Nervoso Central , Eletromiografia , Mielite Transversa , Humanos , Eletromiografia/métodos , Masculino , Feminino , Mielite Transversa/diagnóstico , Malformações Vasculares do Sistema Nervoso Central/complicações , Malformações Vasculares do Sistema Nervoso Central/fisiopatologia , Malformações Vasculares do Sistema Nervoso Central/diagnóstico , Estudos Retrospectivos , Pessoa de Meia-Idade , Adulto , Idoso , Diagnóstico Diferencial , Doenças da Medula Espinal/diagnóstico , Doenças da Medula Espinal/fisiopatologia , Imageamento por Ressonância Magnética/métodosRESUMO
Introduction: The effects of vitamin B12 metabolism on musculoskeletal health and the exact mechanism have not been fully determined. Our study aimed to assess the association of vitamin B12 and its biomarkers with musculoskeletal health in middle-aged and older adults. Methods: The data from the National Health and Nutrition Examination Survey 2001-2002 were used to investigate the effects of serum vitamin B12 and its biomarkers (homocysteine and methylmalonic acid) on skeletal muscle health. Bone mineral density (BMD), lean mass, gait speed and knee extensor strength were used as indicators for musculoskeletal health. Results: Serum vitamin B12 level was positively correlated with the total and appendicular lean mass (ß = 584.83, P = 0.044; ß = 291.65, P = 0.043) in older adults over 65 years of age. In the full population, plasma homocysteine was associated with total lean mass, appendicular lean mass, gait speed, and knee extensor strength (all P < 0.05). Among older adults over 65 years of age, homocysteine level was significantly negatively correlated with gait speed and knee extensor strength (ß = -12.75, P = 0.019; ß = -0.06, P <0.001). Plasma methylmalonic acid was negatively associated with total BMD and femur BMD in the full population (ß = -0.01, P = 0.018; ß = -0.01, P = 0.004). In older adults, methylmalonic acid significantly affected total BMD, femur BMD and knee extensor strength (ß = -0.01, P = 0.048; ß = -0.01, P = 0.025; ß = -7.53, P = 0.015). Conclusions: Vitamin B12 and its biomarkers are closely related to BMD, body composition, muscle strength and physical function in middle-aged and older adults. Vitamin B12 may be an important indicator of musculoskeletal health in the elderly.
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Biomarcadores , Densidade Óssea , Homocisteína , Ácido Metilmalônico , Força Muscular , Vitamina B 12 , Humanos , Vitamina B 12/sangue , Idoso , Feminino , Masculino , Biomarcadores/sangue , Pessoa de Meia-Idade , Densidade Óssea/fisiologia , Homocisteína/sangue , Ácido Metilmalônico/sangue , Força Muscular/fisiologia , Músculo Esquelético/metabolismo , Inquéritos Nutricionais , Composição Corporal , Estudos Transversais , Idoso de 80 Anos ou maisRESUMO
Homologous recombination (HR) plays a key role in maintaining genomic stability, and the efficiency of the HR system is closely associated with tumor response to chemotherapy. Our previous work reported that CK2 kinase phosphorylates HIV Tat-specific factor 1 (HTATSF1) Ser748 to facilitate HTATSF1 interaction with TOPBP1, which in turn, promotes RAD51 recruitment and HR repair. However, the clinical implication of the CK2-HTATSF1-TOPBP1 pathway in tumorigenesis and chemotherapeutic response remains to be elucidated. Here, we report that the CK2-HTATSF1-TOPBP1 axis is generally hyperactivated in multiple malignancies and renders breast tumors less responsive to chemotherapy. In contrast, deletion mutations of each gene in this axis, which also occur in breast and lung tumor samples, predict higher HR deficiency scores, and tumor cells bearing a loss-of-function mutation of HTATSF1 are vulnerable to poly(ADP-ribose) polymerase inhibitors or platinum drugs. Taken together, our study suggests that the integrity of the CK2-HTATSF1-TOPBP1 axis is closely linked to tumorigenesis and serves as an indicator of tumor HR status and modulates chemotherapy response.
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Proteínas de Transporte , Caseína Quinase II , Proteínas de Ligação a DNA , Transdução de Sinais , Humanos , Proteínas de Ligação a DNA/metabolismo , Proteínas de Ligação a DNA/genética , Transdução de Sinais/efeitos dos fármacos , Caseína Quinase II/metabolismo , Caseína Quinase II/genética , Proteínas de Transporte/metabolismo , Proteínas de Transporte/genética , Animais , Feminino , Camundongos , Linhagem Celular Tumoral , Proteínas Nucleares/metabolismo , Proteínas Nucleares/genética , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Neoplasias da Mama/metabolismo , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Neoplasias/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/patologiaRESUMO
Citrus reticulata cv. Chachiensis (CRC) is an important medicinal plant, its dried mature peels named "Guangchenpi", has been used as a traditional Chinese medicine to treat cough, indigestion, and lung diseases for several hundred years. However, the biosynthesis of the crucial natural products polymethoxylated flavonoids (PMFs) in CRC remains unclear. Here, we report a chromosome-scale genome assembly of CRC with the size of 314.96 Mb and a contig N50 of 16.22 Mb. Using multi-omics resources, we discover a putative caffeic acid O-methyltransferase (CcOMT1) that can transfer a methyl group to the 3-hydroxyl of natsudaidain to form 3,5,6,7,8,3',4'-heptamethoxyflavone (HPMF). Based on transient overexpression and virus-induced gene silencing experiments, we propose that CcOMT1 is a candidate enzyme in HPMF biosynthesis. In addition, a potential gene regulatory network associated with PMF biosynthesis is identified. This study provides insights into PMF biosynthesis and may assist future research on mining genes for the biosynthesis of plant-based medicines.
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Citrus , Flavonoides , Metiltransferases , Citrus/genética , Citrus/metabolismo , Flavonoides/biossíntese , Flavonoides/metabolismo , Metiltransferases/metabolismo , Metiltransferases/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas , Genoma de Planta , Redes Reguladoras de Genes , MultiômicaRESUMO
Ovarian cancer is a common tumor among women. It is often asymptomatic in the early stages, with most cases already at stage III to IVE at the time of diagnosis. Direct spread and lymphatic metastasis are the primary modes of metastasis, whereas hematogenous spread is rare. An initial diagnosis of ovarian cancer that has metastasized to the stomach is also uncommon. Therefore, clear treatment methods and prognostic data for such metastasis are lacking. In our hospital, we encountered a patient with an initial imaging diagnosis of a gastric tumor and a history of an ovarian tumor with endoscopic abdominal metastasis. Based on the characteristics of the case, the two tumors were considered to be the same. After chemotherapy, a partial response was observed in the stomach and pelvic lesions, suggesting the effectiveness of the treatment. Through three treatments of recurrence, gastroscopy confirmed the stomach to be a metastatic site. Therefore, determining the primary source of advanced tumors is crucial in guiding treatment decisions. Clinicians must approach this comprehensively, relying on thorough evaluation and personal experience.
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Cistadenocarcinoma Seroso , Neoplasias Ovarianas , Neoplasias Gástricas , Feminino , Humanos , Carcinoma Epitelial do Ovário , Neoplasias Ovarianas/patologia , Prognóstico , Neoplasias Gástricas/diagnóstico por imagem , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/patologia , Estômago/diagnóstico por imagem , Estômago/patologiaRESUMO
Home health care companies provide health care services to patients in their homes. Due to increasing demand, the provision of home health care services requires effective management of operational costs while satisfying both patients and caregivers. In practice, uncertain service times might lead to considerable delays that adversely affect service quality. To this end, this paper proposes a new bi-objective optimization problem to model the routing and scheduling problems under uncertainty in home health care, considering the qualification and workload of caregivers. A mixed-integer linear programming formulation is developed. Motivated by the challenge of computational time, we propose the Adaptive Large Neighborhood Search embedded in an Enhanced Multi-Directional Local Search framework (ALNS-EMDLS). A stochastic ALNS-EMDLS is introduced to handle uncertain service times for patients. Three kinds of metrics for evaluating the Pareto fronts highlight the efficiency of our proposed method. The sensitivity analysis validates the robustness of the proposed model and method. Finally, we apply the method to a real-life case and provide managerial recommendations.
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Serviços de Assistência Domiciliar , Medicina , Humanos , Incerteza , Fatores de Tempo , Eficiência OrganizacionalRESUMO
The impaired differentiation ability of resident cells and disordered immune microenvironment in periodontitis pose a huge challenge for bone regeneration. Herein, we construct a piezoelectric hydrogel to rescue the impaired osteogenic capability and rebuild the regenerative immune microenvironment through bioenergetic activation. Under local mechanical stress, the piezoelectric hydrogel generated piezopotential that initiates osteogenic differentiation of inflammatory periodontal ligament stem cells (PDLSCs) via modulating energy metabolism and promoting adenosine triphosphate (ATP) synthesis. Moreover, it also reshapes an anti-inflammatory and pro-regenerative niche through switching M1 macrophages to the M2 phenotype. The synergy of tilapia gelatin and piezoelectric stimulation enhances in situ regeneration in periodontal inflammatory defects of rats. These findings pave a new pathway for treating periodontitis and other immune-related bone defects through piezoelectric stimulation-enabled energy metabolism modulation and immunomodulation.
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Generalist microbes have adapted to a multitude of environmental stresses through their integrated stress response system. Individual stress responses have been quantified by E. coli metabolism and expression (ME) models under thermal, oxidative and acid stress, respectively. However, the systematic quantification of cross-stress & cross-talk among these stress responses remains lacking. Here, we present StressME: the unified stress response model of E. coli combining thermal (FoldME), oxidative (OxidizeME) and acid (AcidifyME) stress responses. StressME is the most up to date ME model for E. coli and it reproduces all published single-stress ME models. Additionally, it includes refined rate constants to improve prediction accuracy for wild-type and stress-evolved strains. StressME revealed certain optimal proteome allocation strategies associated with cross-stress and cross-talk responses. These stress-optimal proteomes were shaped by trade-offs between protective vs. metabolic enzymes; cytoplasmic vs. periplasmic chaperones; and expression of stress-specific proteins. As StressME is tuned to compute metabolic and gene expression responses under mild acid, oxidative, and thermal stresses, it is useful for engineering and health applications. The modular design of our open-source package also facilitates model expansion (e.g., to new stress mechanisms) by the computational biology community.
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Proteínas de Escherichia coli , Escherichia coli , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Estresse Fisiológico/genética , Oxirredução , Proteínas de Choque Térmico/metabolismo , Ácidos/metabolismo , Expressão GênicaRESUMO
Appropriate DNA end synapsis, regulated by core components of the synaptic complex including KU70-KU80, LIG4, XRCC4, and XLF, is central to non-homologous end joining (NHEJ) repair of chromatinized DNA double-strand breaks (DSBs). However, it remains enigmatic whether chromatin modifications can influence the formation of NHEJ synaptic complex at DNA ends, and if so, how this is achieved. Here, we report that the mitotic deacetylase complex (MiDAC) serves as a key regulator of DNA end synapsis during NHEJ repair in mammalian cells. Mechanistically, MiDAC removes combinatorial acetyl marks on histone H2A (H2AK5acK9ac) around DSB-proximal chromatin, suppressing hyperaccumulation of bromodomain-containing protein BRD4 that would otherwise undergo liquid-liquid phase separation with KU80 and prevent the proper installation of LIG4-XRCC4-XLF onto DSB ends. This study provides mechanistic insight into the control of NHEJ synaptic complex assembly by a specific chromatin signature and highlights the critical role of H2A hypoacetylation in restraining unscheduled compartmentalization of DNA repair machinery.
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Cromatina , Proteínas Nucleares , Animais , Cromatina/genética , Proteínas Nucleares/metabolismo , Fatores de Transcrição/metabolismo , DNA/genética , Reparo do DNA por Junção de Extremidades , Histonas/genética , Histonas/metabolismo , Pareamento Cromossômico , Autoantígeno Ku/genética , Autoantígeno Ku/metabolismo , Mamíferos/metabolismoRESUMO
Mulberry (Morus alba L.), a kind of common fruits widely cultivated worldwide, has been proven various biological activities. However, its potential role in the progression of knee osteoarthritis (KOA) remains unclear. This study aims to investigate the potential protective effects of crude polysaccharide extracted from mulberry fruit, referred to as a complex blend of polysaccharides and other unidentified extracted impurities, on KOA progression. The KOA rats were established by injection of 1 mg sodium monoiodoacetate into knee, and administrated with crude mulberry polysaccharide (Mup) by gastric gavage for 4 weeks. Furthermore, intestinal bacteria clearance assay (IBCA) and fecal microbiota transplantation were conducted for the evaluation of the effect of gut microbiota (GM) on KOA. Our findings demonstrated that Mup, particularly at a dosage of 200 mg/kg, effectively improved abnormal gait patterns, reduced the level of inflammation, mitigated subchondral bone loss, restored compromised joint surfaces, alleviated cartilage destruction, and positively modulated the dysregulated profile of GM in KOA rats. Moreover, IBCA compromised the protective effects of Mup, while transplantation of fecal bacteria from Mup-treated rats facilitated KOA recovery. Collectively, our study suggested that Mup had the potential to ameliorate the progression of KOA, potentially through its modulation of GM profile.
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Microbioma Gastrointestinal , Morus , Osteoartrite do Joelho , Ratos , Animais , Osteoartrite do Joelho/tratamento farmacológico , Frutas , Polissacarídeos/farmacologia , Polissacarídeos/uso terapêuticoRESUMO
BACKGROUND: Cinnamomum camphora (L.) Presl (C. camphora) is an evergreen broad-leaved tree cultivated in subtropical China. The use of C. camphora as clonal cuttings for coppice management has become popular recently. However, little is known about the relationship between soil core microbiota and ecosystem multi-functionality under tree planting. Particularly, the effects of soil core microbiota on maintaining ecosystem multi-functionality under C. camphora coppice planting remained unclear. MATERIALS AND METHODS: In this study, we collected soil samples from three points (i.e., the abandoned land, the root zone, and the transition zone) in the C. camphora coppice planting to investigate whether core microbiota influences ecosystem multi-functions. RESULTS: The result showed a significant difference in soil core microbiota community between the abandoned land (AL), root zone (RZ), and transition zone (TZ), and soil ecosystem multi-functionality of core microbiota in RZ had increased significantly (by 230.8%) compared to the AL. Soil core microbiota played a more significant influence on ecosystem multi-functionality than the non-core microbiota. Moreover, the co-occurrence network demonstrated that the soil ecosystem network consisted of five major ecological clusters. Soil core microbiota within cluster 1 were significantly higher than in cluster 4, and there is also a higher Copiotrophs/Oligotrophs ratio in cluster 1. Our results corroborated that soil core microbiota is crucial for maintaining ecosystem multi-functionality. Especially, the core taxa within the clusters of networks under tree planting, with the same ecological preferences, had a significant contribution to ecosystem multi-functionality. CONCLUSION: Overall, our results provide further insight into the linkage between core taxa and ecosystem multi-functionality. This enables us to predict how ecosystem functions respond to the environmental changes in areas under the C. camphora coppice planting. Thus, conserving the soil microbiota, especially the core taxa, is essential to maintaining the multiple ecosystem functions under the C. camphora coppice planting.
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Cinnamomum camphora , Microbiota , China , Solo , ÁrvoresRESUMO
Objective: This study aims to develop and validate a suitable scale for assessing the level of fertility information support in reproductive-aged breast cancer patients. Methods: We utilized an exploratory mixed methods approach, dividing the study into two phases: scale development and validation. In Phase 1, initial items were generated through literature review and qualitative interviews. In Phase 2, a cross-sectional survey was conducted involving 468 reproductive-aged breast cancer patients to evaluate the scale's validity and reliability. Scale items underwent item analysis, and their validity and reliability were assessed using Cronbach's α coefficient, retest reliability, content validity, structural validity, and convergent validity. Results: The final scale comprised 17 items, and exploratory factor analysis revealed three common dimensions with internal consistency coefficients of 0.894, 0.816, and 0.869. The overall internal consistency of the scale was 0.908, with a retest reliability Pearson correlation coefficient of 0.937, indicating strong stability and reliability. The construct validity of the scale was excellent (χ2 = 198.606, df = 113, χ2/df = 1.758, root mean square of approximation error = 0.055, goodness-of-fit index = 0.917, comparative fit index = 0.979, null fitting index = 0.953, and incremental fitting index = 0.979). Conclusions: Our fertility information support scale for reproductive-aged breast cancer patients demonstrates favorable psychometric properties. It serves as a valuable tool for evaluating fertility information support levels among these patients, assisting medical professionals in addressing fertility concerns and implementing personalized support programs. However, further research is needed to investigate the applicability of this scale in patients from diverse social and cultural backgrounds.
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Amblyopia affects development of children's monocular vision and binocular function and becomes a largely intractable problem with increasing aging. This study is to investigate the binocular function and evaluate efficacy of digital therapy in children 8-13 years of age with anisometropic amblyopia. The patients in the digital therapy group performed the training with the digital amblyopia therapeutic software. The visual acuity and binocular function (perceptual eye position [PEP], suppression, and stereopsis) were examined at the first visit and 3-month post-treatment. Twenty-three cases in the control group and 25 cases in the digital therapy group were enrolled. The results revealed that 3-month digital therapy can effectively improve corrected distance visual acuity (CDVA) and improve the binocular function, including PEP, suppression, and second-order stereopsis in children with anisometropic amblyopia, 8-13 years of age. Digital therapy for amblyopia can effectively improve monocular CDVA of amblyopic eyes and binocular function in older children with anisometropic amblyopia.
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Ambliopia , Criança , Humanos , Ambliopia/terapia , Visão Binocular , Acuidade Visual , SoftwareRESUMO
V2O5 is a promising pseudocapacitive material for electrochemical energy storage with balanced power and energy density. Understanding the charge-storage mechanism is of significance to further improve the rate performance. Here, we report an electrochemical study of individual V2O5 particles using scanning electrochemical cell microscopy with colocalized electron microscopy. A carbon sputtering procedure is proposed for the pristine V2O5 particles to improve their structure stability and electronic conductivity. The achieved high-quality electrochemical cyclic voltammetry results, structural integrity, and high oxidation to reduction charge ratio (as high as 97.74%) assured further quantitative analysis of the pseudocapacitive behavior of single particles and correlation with local particle structures. A broad range of capacitive contribution is revealed, with an average ratio of 76% at 1.0 V/s. This study provides new opportunities for quantitative analysis of the electrochemical charge-storage process at single particles, especially for electrode materials with electrolyte-induced instability.
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Transition-metal (oxy)hydroxides are among the most active and studied catalysts for the oxygen evolution reaction in alkaline electrolytes. However, the geometric distribution of active sites is still elusive. Here, using the well-defined crystalline iron-substituted cobalt hydroxide as a model catalyst, we reported the scanning electrochemical cell microscopy (SECCM) study of single-crystalline nanoplates, where the oxygen evolution reaction at individual nanoplates was isolated and evaluated independently. With integrated prior- and post-SECCM scanning electron microscopy of the catalyst morphology, correlated structure-activity information of individual electrocatalysts was obtained. Our result reveals that while the active sites are largely located at the edges of the pristine Co(OH)2 nanoplates, the Fe lattice incorporation significantly promotes the basal plane activities. Our approach of correlative imaging provides new insights into the effect of iron incorporation on active site distribution across nano-electrocatalysts.
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Vegetation restoration can effectively improve the ecological environment of mining areas, enhance the ecological service function, and promote the carbon sequestration and sink increase in the ecosystem. The soil carbon cycle plays an important role in the biogeochemical cycle. The abundance of functional genes can predict the material cycling potential and metabolic characteristics of soil microorganisms. Previous studies on functional microorganisms have mainly focused on large ecosystems such as farmland, forest, and wetland, but relatively little attention has been paid to complex ecosystems with great anthropogenic interference and special functions, such as mines. Clarifying the succession and driving mechanism of functional microorganisms in reclaimed soil under the guidance of vegetation restoration is helpful to fully explore how functional microorganisms change with the change in abiotic and biotic conditions. Therefore, 25 topsoil samples were collected from grassland (GL), brushland (BL), coniferous forests (CF), broadleaf forests (BF), and mixed coniferous and broadleaf forests (MF) in the reclamation area of the Heidaigou open pit waste dump on the Loess Plateau. The absolute abundance of soil carbon cycle functional genes was determined using real-time fluorescence quantitative PCR to explore the effect of vegetation restoration on the abundance of carbon cycle-related functional genes in soil and its internal mechanism. The results showed that:â the effects of different vegetation restoration types on the chemical properties of reclaimed soil and the abundance of functional genes related to the carbon cycle were significantly different (P<0.05). GL and BL showed significantly better accumulation of soil organic carbon, total nitrogen, and nitrate nitrogen (P<0.05) than that in CF. â¡ The gene abundance of rbcL, acsA, and mct was the highest among all carbon fixation genes. The abundance of functional genes related to carbon cycle in BF soil was higher than that in other types, which was closely related to the high activity of ammonium nitrogen and BG enzymes and the low activity of readily oxidized organic carbon and urease in BF soil. The functional gene abundance of carbon degradation and methane metabolism was positively correlated with ammonium nitrogen and BG enzyme activity and negatively correlated with organic carbon, total nitrogen, readily oxidized organic carbon, nitrate nitrogen, and urease activity (P<0.05). ⢠Different vegetation types could directly affect soil BG enzyme activity or affect soil nitrate nitrogen content, thus indirectly affecting BG enzyme activity, in turn manipulating the abundance of functional genes related to the carbon cycle. This study is helpful to understand the effects of different vegetation restoration types on the functional genes related to the carbon cycle in the soil of mining areas on the Loess Plateau and provides a scientific basis for ecological restoration and ecological carbon sequestration and sink enhancement in mining areas.