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Dynamic protein phosphorylation and dephosphorylation are essential regulatory mechanisms that ensure proper cellular signaling and biological functions. Deregulation of either reaction has been implicated in several human diseases. Here, we focus on the mechanisms that govern the specificity of the dephosphorylation reaction. Most cellular serine/threonine dephosphorylation is catalyzed by 13 highly conserved phosphoprotein phosphatase (PPP) catalytic subunits, which form hundreds of holoenzymes by binding to regulatory and scaffolding subunits. PPP holoenzymes recognize phosphorylation site consensus motifs and interact with short linear motifs (SLiMs) or structural elements distal to the phosphorylation site. We review recent advances in understanding the mechanisms of PPP site-specific dephosphorylation preference and substrate recruitment and highlight examples of their interplay in the regulation of cell division.
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Fosfoproteínas Fosfatases , Humanos , Fosforilação , Fosfoproteínas Fosfatases/metabolismo , Domínio Catalítico , Holoenzimas/química , Holoenzimas/metabolismo , Especificidade por SubstratoRESUMO
Liquid methanol has the potential to be the hydrogen energy carrier and storage medium for the future green economy. However, there are still many challenges before zero-emission, affordable molecular H2 can be extracted from methanol with high performance. Here, we present noble-metal-free Cu-WC/W plasmonic nanohybrids which exhibit unsurpassed solar H2 extraction efficiency from pure methanol of 2,176.7 µmol g-1 h-1 at room temperature and normal pressure. Macro-to-micro experiments and simulations unveil that local reaction microenvironments are generated by the coperturbation of WC/W's lattice strain and infrared-plasmonic electric field. It enables spontaneous but selective zero-emission reaction pathways. Such microenvironments are found to be highly cooperative with solar-broadband-plasmon-excited charge carriers flowing from Cu to WC surfaces for efficient stable CH3OH plasmonic reforming with C3-dominated liquid products and 100% selective gaseous H2. Such high efficiency, without any COx emission, can be sustained for over a thousand-hour operation without obvious degradation.
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PP2A is an essential protein phosphatase that regulates most cellular processes through the formation of holoenzymes containing distinct regulatory B-subunits. Only a limited number of PP2A-regulated phosphorylation sites are known. This hampers our understanding of the mechanisms of site-specific dephosphorylation and of its tumor suppressor functions. Here, we develop phosphoproteomic strategies for global substrate identification of PP2A-B56 and PP2A-B55 holoenzymes. Strikingly, we find that B-subunits directly affect the dephosphorylation site preference of the PP2A catalytic subunit, resulting in unique patterns of kinase opposition. For PP2A-B56, these patterns are further modulated by affinity and position of B56 binding motifs. Our screens identify phosphorylation sites in the cancer target ADAM17 that are regulated through a conserved B56 binding site. Binding of PP2A-B56 to ADAM17 protease decreases growth factor signaling and tumor development in mice. This work provides a roadmap for the identification of phosphatase substrates and reveals unexpected mechanisms governing PP2A dephosphorylation site specificity and tumor suppressor function.
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Proteína ADAM17/metabolismo , Proteína Fosfatase 2/metabolismo , Proteína ADAM17/genética , Motivos de Aminoácidos , Animais , Sítios de Ligação , Células HeLa , Humanos , Camundongos , FosforilaçãoRESUMO
Metal halide perovskite solar cells have achieved tremendous progress and have attracted enormous research and development efforts since the first report of demonstration in 2009. Due to fabrication versatility, many heat treatment methods can be utilized to achieve perovskite film crystallization. Herein, 10.6 µm carbon dioxide laser process is successfully developed for the first time for perovskite film crystallization. In addition, this is the first time formamidinium lead triiodide solar cells by laser annealing under ambient are demonstrated. The champion cell produces a power conversion efficiency of 21.8%, the highest for laser-annealed perovskite cells. And this is achieved without any additive, passivation, or post-treatment.
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Luminescent coupling (LC) is a key phenomenon in monolithic tandem solar cells. This study presents a nondestructive technique to quantitatively evaluate the LC effect, addressing a gap in the existing predictions made by optical modeling. The method involves measuring the ratio of photons emitted from the high bandgap top cell that escape through the rear, contributing additional current to the bottom cell, and to those escaping from the front side of top cell. The findings indicate that in the analyzed monolithic perovskite/silicon tandem solar cells, more than 85% of the emitted photons escaping from the perovskite top cell are used to generate additional current in the bottom cell. This process notably reduces the mismatch in the generated current between each subcell, particularly when the current is limited by the low bandgap subcell. The presented method is applicable to a variety of monolithic tandem structures, providing vital information for subcell characterization, providing vital information for predicting energy output and optimization for outdoor applications.
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EXOC5 is a crucial component of a large multi-subunit tethering complex, the exocyst complex, that is required for fusion of secretory vesicles with the plasma membrane. Exoc5 deleted mice die as early embryos. Therefore, to determine the role of EXOC5 in follicular and oocyte development, it was necessary to produce a conditional knockout (cKO), Zp3-Exoc5-cKO, in which Exoc5 was deleted only in oocytes. The first wave of folliculogenesis appeared histologically normal and progressed to the antral stage. However, after IVF with normal sperm, oocytes collected from the first wave (superovulated 21-day-old cKO mice) were shown to be developmentally incompetent. Adult follicular waves did not progress beyond the secondary follicle stage where they underwent apoptosis. Female cKO mice were infertile. Overall, these data suggest that the first wave of folliculogenesis is less sensitive to oocyte-specific loss of Exoc5, but the resulting gametes have reduced developmental competence. In contrast, subsequent waves of folliculogenesis require oocyte-specific Exoc5 for development past the preantral follicle stage. The Zp3-Exoc5-cKO mouse provides a model for disrupting folliculogenesis that also enables the separation between the first and subsequent waves of folliculogenesis.
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Camundongos Knockout , Oócitos , Oogênese , Folículo Ovariano , Animais , Feminino , Oogênese/genética , Oogênese/fisiologia , Oócitos/metabolismo , Camundongos , Folículo Ovariano/metabolismo , Proteínas de Transporte Vesicular/genética , Proteínas de Transporte Vesicular/metabolismo , Masculino , Glicoproteínas da Zona Pelúcida/genética , Glicoproteínas da Zona Pelúcida/metabolismoRESUMO
Phosphoprotein phosphatases (PPPs) regulate major signaling pathways, but the determinants of phosphatase specificity are poorly understood. This is because methods to investigate this at scale are lacking. Here, we develop a novel in vitro assay, MRBLE:Dephos, that allows multiplexing of dephosphorylation reactions to determine phosphatase preferences. Using MRBLE:Dephos, we establish amino acid preferences of the residues surrounding the dephosphorylation site for PP1 and PP2A-B55, which reveals common and unique preferences. To compare the MRBLE:Dephos results to cellular substrates, we focused on mitotic exit that requires extensive dephosphorylation by PP1 and PP2A-B55. We use specific inhibition of PP1 and PP2A-B55 in mitotic exit lysates coupled with phosphoproteomics to identify more than 2,000 regulated sites. Importantly, the sites dephosphorylated during mitotic exit reveal key signatures that are consistent with MRBLE:Dephos. Furthermore, integration of our phosphoproteomic data with mitotic interactomes of PP1 and PP2A-B55 provides insight into how binding of phosphatases to substrates shapes dephosphorylation. Collectively, we develop novel approaches to investigate protein phosphatases that provide insight into mitotic exit regulation.
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Mitose , Proteína Fosfatase 2 , Fosforilação , Proteína Fosfatase 2/química , Proteína Fosfatase 2/genética , Proteína Fosfatase 2/metabolismo , Transdução de Sinais , Especificidade por SubstratoRESUMO
GLABRA2 (GL2), a class IV homeodomain leucine-zipper (HD-Zip IV) transcription factor (TF) from Arabidopsis, is a developmental regulator of specialized cell types in the epidermis. GL2 contains a monopartite nuclear localization sequence (NLS) that is conserved in most HD-Zip IV members across the plants. We demonstrate that NLS mutations affect nuclear transport and result in a loss-of-function phenotypes. NLS fusions to EYFP show that it is sufficient for nuclear localization in roots and trichomes. Despite partial overlap of the NLS with the homeodomain, genetic dissection indicates that nuclear localization and DNA binding are separable functions. Affinity purification of GL2 from plants followed by MS-based proteomics identified Importin α (IMPα) isoforms as potential GL2 interactors. NLS structural prediction and molecular docking studies with IMPα-3 revealed major interacting residues. Cytosolic yeast two-hybrid assays and co-immunoprecipitation experiments with recombinant proteins verified NLS-dependent interactions between GL2 and several IMPα isoforms. IMPα triple mutants (impα-1,2,3) exhibit abnormal trichome formation and defects in GL2 nuclear localization in trichomes, consistent tissue-specific and redundant functions of IMPα isoforms. Taken together, our findings provide mechanistic evidence for IMPα-dependent nuclear localization of GL2 in Arabidopsis, a process that is critical for cell-type differentiation of the epidermis.
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BACKGROUND: The number of Hospital-at-Home (HaH) programs rapidly increased during the COVID-19 pandemic and after issuance of Centers for Medicare and Medicaid Services' (CMS) Acute Hospital Care at Home (AHCaH) waiver. However, there remains little evidence on effective strategies to equitably expand HaH utilization. OBJECTIVE: Evaluate the effects of a multifaceted implementation strategy on HaH utilization over time. DESIGN: Before and after implementation evaluation using electronic health record (EHR) data and interrupted time series analysis, complemented by qualitative interviews with key stakeholders. PARTICIPANTS: Between December 2021 and December 2022, we identified adults hospitalized at six hospitals in North Carolina approved by CMS to participate in the AHCaH waiver program. Eligible adults met criteria for HaH transfer (HaH-eligible clinical condition, qualifying home environment). We conducted semi-structured interviews with 12 HaH patients and 10 referring clinicians. INTERVENTIONS: Two strategies were studied. The discrete implementation strategy (weeks 1-12) included clinician-directed educational outreach. The multifaceted implementation strategy (weeks 13-54) included ongoing clinician-directed educational outreach, local HaH assistance via nurse navigators, involvement of clinical service line executives, and individualized audit and feedback. MEASURES: We assessed weekly averaged HaH capacity utilization, weekly counts of unique referring providers, and patient characteristics. We analyzed themes from qualitative data to determine barriers and facilitators to HaH use. RESULTS: Our evaluation showed week-to-week increases in HaH capacity utilization during the multifaceted implementation strategy period, compared to discrete-period trends (slope-change odds ratio-1.02, 1.01-1.04). Counts of referring providers also increased week to week, compared to discrete-period trends (slope-change means ratio-1.05, 1.03-1.07). The increase in HaH utilization was largest among rural residents (11 to 34%). Barriers included HaH-related information gaps and referral challenges; facilitators included patient-centeredness of HaH care. CONCLUSIONS: A multifaceted implementation strategy was associated with increased HaH capacity utilization, provider adoption, and patient diversity. Health systems may consider similar, contextually relevant multicomponent approaches to equitably expand HaH.
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The pathophysiology of immune thrombocytopenia (ITP) involves immune-mediated platelet destruction. The presence of adipose tissue in obese individuals creates an inflammatory environment that could potentially impact the clinical course and outcomes of ITP. However the relationship between obesity and ITP outcomes has not been well described. We evaluated ITP outcomes in 275 patients diagnosed with primary ITP from 2012 to 2022. Patients were categorized into four groups based on their body mass index (BMI) at diagnosis. Female gender was associated with a lower platelet count at the time of diagnosis at any BMI. Patients with high BMI had lower platelet counts at diagnosis and at platelet nadir (p < 0.001), an increased likelihood of requiring therapy (p < 0.001) and requiring multiple lines of therapy (p = 0.032). Non-obese patients who required corticosteroid treatment experienced a longer remission duration compared to obese patients (p = 0.009) and were less likely to be steroid-dependent (p = 0.048). Our findings suggest that obesity may be a significant risk factor for developing ITP and for ITP prognosis. Future studies are needed to evaluate the role of weight loss intervention in improving ITP outcomes.
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The presence of human immunodeficiency virus (HIV) 1 subtype A6, characterized by the L74I integrase (IN) polymorphism, is associated with confirmed virologic failure in clinical trials of long-acting cabotegravir and rilpivirine. We investigated the effect of L74I on replication capacity (RC) of recombinant viruses carrying this polymorphism in combination with various IN stand-transfer inhibitor resistance mutations. The presence of L74I conferred greater RC to recombinant viruses expressing HIV-1 A6 IN when present together with G118R, G140R, Q148H, and R263K; no significant difference in RC was observed for the Q148K or R mutants. These findings may explain, in part, the association of HIV-1 subtype A6 with virologic failure.
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Infecções por HIV , Inibidores de Integrase de HIV , Integrase de HIV , HIV-1 , Humanos , HIV-1/genética , Substituição de Aminoácidos , Replicação Viral/genética , Oxazinas/uso terapêutico , Inibidores de Integrase de HIV/farmacologia , Inibidores de Integrase de HIV/uso terapêutico , Mutação , Piridonas/farmacologia , Piridonas/uso terapêutico , Infecções por HIV/tratamento farmacológico , Farmacorresistência Viral/genética , Integrase de HIV/genéticaRESUMO
In cereals, the root system is mainly composed of post-embryonic shoot-borne roots, named crown roots. The CROWN ROOTLESS1 (CRL1) transcription factor, belonging to the ASYMMETRIC LEAVES2-LIKE/LATERAL ORGAN BOUNDARIES DOMAIN (ASL/LBD) family, is a key regulator of crown root initiation in rice (Oryza sativa). Here, we show that CRL1 can bind, both in vitro and in vivo, not only the LBD-box, a DNA sequence recognized by several ASL/LBD transcription factors, but also another not previously identified DNA motif that was named CRL1-box. Using rice protoplast transient transactivation assays and a set of previously identified CRL1-regulated genes, we confirm that CRL1 transactivates these genes if they possess at least a CRL1-box or an LBD-box in their promoters. In planta, ChIP-qPCR experiments targeting two of these genes that include both a CRL1- and an LBD-box in their promoter show that CRL1 binds preferentially to the LBD-box in these promoter contexts. CRISPR/Cas9-targeted mutation of these two CRL1-regulated genes, which encode a plant Rho GTPase (OsROP) and a basic helix-loop-helix transcription factor (OsbHLH044), show that both promote crown root development. Finally, we show that OsbHLH044 represses a regulatory module, uncovering how CRL1 regulates specific processes during crown root formation.
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Oryza , DNA/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
Despite the ongoing clinical trials and the introduction of novel treatments over the past few decades, ovarian cancer remains one of the most fatal malignancies in women worldwide. Platinum- and paclitaxel-based chemotherapy is effective in treating the majority of patients with ovarian cancer. However, more than 70% of patients experience recurrence and eventually develop chemoresistance. To improve clinical outcomes in patients with ovarian cancer, novel technologies must be developed for identifying molecular alterations following drug-based treatment of ovarian cancer. Recently, extracellular vesicles (EVs) have gained prominence as the mediators of tumor progression. In this study, we used mass spectrometry to identify the changes in EV protein signatures due to different chemotherapeutic agents used for treating ovarian cancer. By examining these alterations, we identified the specific protein induction patterns of cisplatin alone, paclitaxel alone, and a combination of cisplatin and paclitaxel. Specifically, we found that drug sensitivity was correlated with the expression levels of ANXA5, CD81, and RAB5C in patients receiving cisplatin with paclitaxel. Our findings suggest that chemotherapy-induced changes in EV protein signatures are crucial for the progression of ovarian cancer.
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We previously demonstrated that MnCl2 induces double-stranded DNA breaks in sperm in a process that we term as sperm chromatin fragmentation. Here, we tested if the levels of double-stranded DNA breaks were corelated to the concentration of MnCl2, and we compared this to another agent that causes single-stranded DNA breaks, H2O2. We found that both methods have the advantage of inducing DNA breaks in a concentration-dependent manner. Mouse sperm were treated with varying concentrations of either H2O2 or MnCl2, and the DNA damage was assessed by pulse-field gel electrophoresis, and the alkaline and neutral comet assays. Oocytes were injected with either treated sperm and the resulting embryos analyzed with an embryoscope to detect subtle changes in embryonic development. We confirmed that H2O2 treatment induced primarily single-stranded DNA breaks and MnCl2 induced primarily double-stranded DNA breaks, indicating different mechanisms of damage. These sperm were injected into oocytes, and the development of the resulting embryos followed with an embryoscope equipped with time lapse recording. We found that aberrations in early embryonic development by day 2 with even the lowest levels of DNA damage and that the levels of embryonic aberrations correlated to the concentration of either H2O2 or MnCl2. Low levels of H2O2 caused significantly more aberrations in embryonic development than low levels of MnCl2 even though the levels of DNA damage as measured by comet assays were similar. These data demonstrate that even low levels of sperm DNA damage cause delays and arrests in embryonic development.
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Cromatina , Peróxido de Hidrogênio , Animais , Feminino , Masculino , Camundongos , Gravidez , Dano ao DNA , Fragmentação do DNA , Desenvolvimento Embrionário/genética , Peróxido de Hidrogênio/toxicidade , Sêmen , EspermatozoidesRESUMO
BACKGROUND: Interleukin-1 receptor antagonist (IL-1RA), a member of the IL-1 family, has diverse roles in cancer development. However, the role of IL-1RA in oral squamous cell carcinoma (OSCC), in particular the underlying mechanisms, remains to be elucidated. METHODS: Tumor tissues from OSCC patients were assessed for protein expression by immunohistochemistry. Patient survival was evaluated by Kaplan-Meier curve analysis. Impact of differential IL-1RA expression on cultured OSCC cell lines was assessed in vitro by clonogenic survival, tumorsphere formation, soft agar colony formation, and transwell cell migration and invasion assays. Oxygen consumption rate was measured by Seahorse analyzer or multi-mode plate reader. PCR array was applied to screen human cancer stem cell-related genes, proteome array for phosphorylation status of kinases, and Western blot for protein expression in cultured cells. In vivo tumor growth was investigated by orthotopic xenograft in mice, and protein expression in xenograft tumors assessed by immunohistochemistry. RESULTS: Clinical analysis revealed that elevated IL-1RA expression in OSCC tumor tissues was associated with increased tumor size and cancer stage, and reduced survival in the patient group receiving adjuvant radiotherapy compared to the patient group without adjuvant radiotherapy. In vitro data supported these observations, showing that overexpression of IL-1RA increased OSCC cell growth, migration/invasion abilities, and resistance to ionizing radiation, whereas knockdown of IL-1RA had largely the opposite effects. Additionally, we identified that EGFR/JNK activation and SOX2 expression were modulated by differential IL-1RA expression downstream of mitochondrial metabolism, with application of mitochondrial complex inhibitors suppressing these pathways. Furthermore, in vivo data revealed that treatment with cisplatin or metformin-a mitochondrial complex inhibitor and conventional therapy for type 2 diabetes-reduced IL-1RA-associated xenograft tumor growth as well as EGFR/JNK activation and SOX2 expression. This inhibitory effect was further augmented by combination treatment with cisplatin and metformin. CONCLUSIONS: The current study suggests that IL-1RA promoted OSCC malignancy through mitochondrial metabolism-mediated EGFR/JNK activation and SOX2 expression. Inhibition of this mitochondrial metabolic pathway may present a potential therapeutic strategy in OSCC.
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Carcinoma de Células Escamosas , Diabetes Mellitus Tipo 2 , Neoplasias de Cabeça e Pescoço , Metformina , Neoplasias Bucais , Humanos , Animais , Camundongos , Carcinoma de Células Escamosas/patologia , Neoplasias Bucais/patologia , Proteína Antagonista do Receptor de Interleucina 1/farmacologia , Carcinoma de Células Escamosas de Cabeça e Pescoço , Cisplatino/farmacologia , Linhagem Celular Tumoral , Receptores ErbB/metabolismo , Metformina/farmacologia , Proliferação de Células , Movimento Celular , Fatores de Transcrição SOXB1/farmacologiaRESUMO
Black phosphorene quantum dots (BPQDs) are most commonly derived from high-cost black phosphorus, while previous syntheses from the low-cost red phosphorus (Pred ) allotrope are highly oxidised. Herein, we present an intrinsically scalable method to produce high quality BPQDs, by first ball-milling Pred to create nanocrystalline Pblack and subsequent reductive etching using lithium electride solvated in liquid ammonia. The resultant ~25â nm BPQDs are crystalline with low oxygen content, and spontaneously soluble as individualized monolayers in tertiary amide solvents, as directly imaged by liquid-phase transmission electron microscopy. This new method presents a scalable route to producing quantities of high quality BPQDs for academic and industrial applications.
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BACKGROUND: Delirium poses significant risks to patients, but countermeasures can be taken to mitigate negative outcomes. Accurately forecasting delirium in intensive care unit (ICU) patients could guide proactive intervention. Our primary objective was to predict ICU delirium by applying machine learning to clinical and physiologic data routinely collected in electronic health records. METHODS: Two prediction models were trained and tested using a multicenter database (years of data collection 2014 to 2015), and externally validated on two single-center databases (2001 to 2012 and 2008 to 2019). The primary outcome variable was delirium defined as a positive Confusion Assessment Method for the ICU screen, or an Intensive Care Delirium Screening Checklist of 4 or greater. The first model, named "24-hour model," used data from the 24 h after ICU admission to predict delirium any time afterward. The second model designated "dynamic model," predicted the onset of delirium up to 12 h in advance. Model performance was compared with a widely cited reference model. RESULTS: For the 24-h model, delirium was identified in 2,536 of 18,305 (13.9%), 768 of 5,299 (14.5%), and 5,955 of 36,194 (11.9%) of patient stays, respectively, in the development sample and two validation samples. For the 12-h lead time dynamic model, delirium was identified in 3,791 of 22,234 (17.0%), 994 of 6,166 (16.1%), and 5,955 of 28,440 (20.9%) patient stays, respectively. Mean area under the receiver operating characteristics curve (AUC) (95% CI) for the first 24-h model was 0.785 (0.769 to 0.801), significantly higher than the modified reference model with AUC of 0.730 (0.704 to 0.757). The dynamic model had a mean AUC of 0.845 (0.831 to 0.859) when predicting delirium 12 h in advance. Calibration was similar in both models (mean Brier Score [95% CI] 0.102 [0.097 to 0.108] and 0.111 [0.106 to 0.116]). Model discrimination and calibration were maintained when tested on the validation datasets. CONCLUSIONS: Machine learning models trained with routinely collected electronic health record data accurately predict ICU delirium, supporting dynamic time-sensitive forecasting.
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Delírio , Humanos , Delírio/diagnóstico , Unidades de Terapia Intensiva , Cuidados Críticos/métodos , Hospitalização , Aprendizado de MáquinaRESUMO
BACKGROUND: Multivariate longitudinal data are under-utilized for survival analysis compared to cross-sectional data (CS - data collected once across cohort). Particularly in cardiovascular risk prediction, despite available methods of longitudinal data analysis, the value of longitudinal information has not been established in terms of improved predictive accuracy and clinical applicability. METHODS: We investigated the value of longitudinal data over and above the use of cross-sectional data via 6 distinct modeling strategies from statistics, machine learning, and deep learning that incorporate repeated measures for survival analysis of the time-to-cardiovascular event in the Coronary Artery Risk Development in Young Adults (CARDIA) cohort. We then examined and compared the use of model-specific interpretability methods (Random Survival Forest Variable Importance) and model-agnostic methods (SHapley Additive exPlanation (SHAP) and Temporal Importance Model Explanation (TIME)) in cardiovascular risk prediction using the top-performing models. RESULTS: In a cohort of 3539 participants, longitudinal information from 35 variables that were repeatedly collected in 6 exam visits over 15 years improved subsequent long-term (17 years after) risk prediction by up to 8.3% in C-index compared to using baseline data (0.78 vs. 0.72), and up to approximately 4% compared to using the last observed CS data (0.75). Time-varying AUC was also higher in models using longitudinal data (0.86-0.87 at 5 years, 0.79-0.81 at 10 years) than using baseline or last observed CS data (0.80-0.86 at 5 years, 0.73-0.77 at 10 years). Comparative model interpretability analysis revealed the impact of longitudinal variables on model prediction on both the individual and global scales among different modeling strategies, as well as identifying the best time windows and best timing within that window for event prediction. The best strategy to incorporate longitudinal data for accuracy was time series massive feature extraction, and the easiest interpretable strategy was trajectory clustering. CONCLUSION: Our analysis demonstrates the added value of longitudinal data in predictive accuracy and epidemiological utility in cardiovascular risk survival analysis in young adults via a unified, scalable framework that compares model performance and explainability. The framework can be extended to a larger number of variables and other longitudinal modeling methods. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00005130, Registration Date: 26/05/2000.
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Doenças Cardiovasculares , Humanos , Adulto Jovem , Doenças Cardiovasculares/diagnóstico , Estudos Transversais , Análise de SobrevidaRESUMO
Thrombotic vascular disorders, specifically thromboembolisms, have a significant detrimental effect on public health. Despite the numerous thrombolytic and antithrombotic drugs available, their efficacy in penetrating thrombus formations is limited, and they carry a high risk of promoting bleeding. Consequently, the current medication dosage protocols are inadequate for preventing thrombus formation, and higher doses are necessary to achieve sufficient prevention. By integrating phototherapy with antithrombotic therapy, this study addresses difficulties related to thrombus-targeted drug delivery. We developed self-assembling nanoparticles (NPs) through the optimization of a co-assembly engineering process. These NPs, called DIP-FU-PPy NPs, consist of polypyrrole (PPy), dipyridamole (DIP), and P-selectin-targeted fucoidan (FU) and are designed to be delivered directly to thrombi. DIP-FU-PPy NPs are proposed to offer various potentials, encompassing drug-loading capability, targeted accumulation in thrombus sites, near-infrared (NIR) photothermal-enhanced thrombus management with therapeutic efficacy, and prevention of rethrombosis. As predicted, DIP-FU-PPy NPs prevented thrombus recurrence and emitted visible fluorescence signals during thrombus clot penetration with no adverse effects. Our co-delivery nano-platform is a simple and versatile solution for NIR-phototherapeutic multimodal thrombus control.
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Nanopartículas , Trombose , Dipiridamol/farmacologia , Nanopartículas/uso terapêutico , Selectina-P , Fototerapia/métodos , Polímeros , Pirróis , Trombose/tratamento farmacológico , AnimaisRESUMO
III-nitride nanowire (NW) LEDs have been intensively studied for several emerging applications. However, the performance of these LEDs is still limited due to many factors. A leakage current may cause idle power consumption and affect the reliability and luminescence efficiency of the devices. Hence, it is one of the most important limiting factors from an application point of view. In this context, we have experimentally observed temperature-dependent forward and reverse leakage current-voltage characteristics of InGaN/AlGaN NW-based red microLEDs. The characteristic curves are fitted using different constant parameters such as the space charge term, zero bias current, and the characteristic energy. They are found to have error bars of less than 10%. The extra space charge term is believed to be due to inherent space charges trapped with the NWs and presents at every instance of the operation of the diode. The characteristic energy and ideality factors are compared to the reported values. An Arrhenius plot is used to calculate the thermal activation energy in the high- and low-temperature regions for both bias conditions. Our results show that the voltage-dependent activation energy is found to be about double in the case of the forward bias compared to that of the reverse bias in all voltage ranges. However, in a high voltage regime, the magnitudes of these parameters are almost four and six times greater for the forward and reverse biases, respectively, compared to those in the lower voltage regions. This study presents vital insight into the design and fabrication of high-performance NW-based LEDs.