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1.
Nat Immunol ; 23(8): 1256-1272, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35902638

RESUMEN

The recombination-activating genes (RAG) 1 and 2 are indispensable for diversifying the primary B cell receptor repertoire and pruning self-reactive clones via receptor editing in the bone marrow; however, the impact of RAG1/RAG2 on peripheral tolerance is unknown. Partial RAG deficiency (pRD) manifesting with late-onset immune dysregulation represents an 'experiment of nature' to explore this conundrum. By studying B cell development and subset-specific repertoires in pRD, we demonstrate that reduced RAG activity impinges on peripheral tolerance through the generation of a restricted primary B cell repertoire, persistent antigenic stimulation and an inflammatory milieu with elevated B cell-activating factor. This unique environment gradually provokes profound B cell dysregulation with widespread activation, remarkable extrafollicular maturation and persistence, expansion and somatic diversification of self-reactive clones. Through the model of pRD, we reveal a RAG-dependent 'domino effect' that impacts stringency of tolerance and B cell fate in the periphery.


Asunto(s)
Linfocitos B , Proteínas de Unión al ADN , Proteínas de Homeodominio , Proteínas Nucleares , Diferenciación Celular , Proteínas de Unión al ADN/deficiencia , Proteínas de Unión al ADN/genética , Proteínas de Homeodominio/genética , Humanos , Tolerancia Inmunológica , Recuento de Linfocitos , Proteínas Nucleares/deficiencia
2.
Brief Bioinform ; 24(4)2023 07 20.
Artículo en Inglés | MEDLINE | ID: mdl-37280185

RESUMEN

The three-dimensional structure of RNA molecules plays a critical role in a wide range of cellular processes encompassing functions from riboswitches to epigenetic regulation. These RNA structures are incredibly dynamic and can indeed be described aptly as an ensemble of structures that shifts in distribution depending on different cellular conditions. Thus, the computational prediction of RNA structure poses a unique challenge, even as computational protein folding has seen great advances. In this review, we focus on a variety of machine learning-based methods that have been developed to predict RNA molecules' secondary structure, as well as more complex tertiary structures. We survey commonly used modeling strategies, and how many are inspired by or incorporate thermodynamic principles. We discuss the shortcomings that various design decisions entail and propose future directions that could build off these methods to yield more robust, accurate RNA structure predictions.


Asunto(s)
Epigénesis Genética , ARN , ARN/metabolismo , Aprendizaje Automático , Estructura Secundaria de Proteína , Biología Computacional/métodos
3.
Nat Chem Biol ; 19(11): 1406-1414, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37770699

RESUMEN

The flavoenzyme nicotine oxidoreductase (NicA2) is a promising injectable treatment to aid in the cessation of smoking, a behavior responsible for one in ten deaths worldwide. NicA2 acts by degrading nicotine in the bloodstream before it reaches the brain. Clinical use of NicA2 is limited by its poor catalytic activity in the absence of its natural electron acceptor CycN. Without CycN, NicA2 is instead oxidized slowly by dioxygen (O2), necessitating unfeasibly large doses in a therapeutic setting. Here, we report a genetic selection strategy that directly links CycN-independent activity of NicA2 to growth of Pseudomonas putida S16. This selection enabled us to evolve NicA2 variants with substantial improvement in their rate of oxidation by O2. The encoded mutations cluster around a putative O2 tunnel, increasing flexibility and accessibility to O2 in this region. These mutations further confer desirable clinical properties. A variant form of NicA2 is tenfold more effective than the wild type at degrading nicotine in the bloodstream of rats.


Asunto(s)
Nicotina , Pseudomonas putida , Ratas , Animales , Oxígeno , Oxidorreductasas/metabolismo , Oxidación-Reducción
4.
EMBO J ; 39(20): e104231, 2020 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-32882062

RESUMEN

Bile salts are secreted into the gastrointestinal tract to aid in the absorption of lipids. In addition, bile salts show potent antimicrobial activity in part by mediating bacterial protein unfolding and aggregation. Here, using a protein folding sensor, we made the surprising discovery that the Escherichia coli periplasmic glycerol-3-phosphate (G3P)-binding protein UgpB can serve, in the absence of its substrate, as a potent molecular chaperone that exhibits anti-aggregation activity against bile salt-induced protein aggregation. The substrate G3P, which is known to accumulate in the later compartments of the digestive system, triggers a functional switch between UgpB's activity as a molecular chaperone and its activity as a G3P transporter. A UgpB mutant unable to bind G3P is constitutively active as a chaperone, and its crystal structure shows that it contains a deep surface groove absent in the G3P-bound wild-type UgpB. Our work illustrates how evolution may be able to convert threats into signals that first activate and then inactivate a chaperone at the protein level in a manner that bypasses the need for ATP.


Asunto(s)
Bilis/metabolismo , Proteínas Portadoras/química , Proteínas Portadoras/metabolismo , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/metabolismo , Escherichia coli/metabolismo , Glicerofosfatos/metabolismo , Chaperonas Moleculares/metabolismo , Ampicilina/farmacología , Proteínas Portadoras/genética , Dicroismo Circular , Cristalografía por Rayos X , Elementos Transponibles de ADN/genética , Proteínas de Escherichia coli/genética , Eliminación de Gen , Secuenciación de Nucleótidos de Alto Rendimiento , Concentración de Iones de Hidrógeno , Chaperonas Moleculares/química , Chaperonas Moleculares/genética , Conformación Molecular , Simulación del Acoplamiento Molecular , Mutación , Unión Proteica , Conformación Proteica , Pliegue de Proteína , Proteoma/metabolismo
5.
Small ; : e2400724, 2024 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-38639018

RESUMEN

The lack of intrinsic active sites for photocatalytic CO2 reduction reaction (CO2RR) and fast recombination rate of charge carriers are the main obstacles to achieving high photocatalytic activity. In this work, a novel phosphorus and boron binary-doped graphitic carbon nitride, highly porous material that exhibits powerful photocatalytic CO2 reduction activity, specifically toward selective CO generation, is disclosed. The coexistence of Lewis-acidic and Lewis-basic sites plays a key role in tuning the electronic structure, promoting charge distribution, extending light-harvesting ability, and promoting dissociation of excitons into active carriers. Porosity and dual dopants create local chemical environments that activate the pyridinic nitrogen atom between the phosphorus and boron atoms on the exposed surface, enabling it to function as an active site for CO2RR. The P-N-B triad is found to lower the activation barrier for reduction of CO2 by stabilizing the COOH reaction intermediate and altering the rate-determining step. As a result, CO yield increased to 22.45 µmol g-1 h-1 under visible light irradiation, which is ≈12 times larger than that of pristine graphitic carbon nitride. This study provides insights into the mechanism of charge carrier dynamics and active site determination, contributing to the understanding of the photocatalytic CO2RR mechanism.

6.
Chemistry ; : e202400885, 2024 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-39032088

RESUMEN

Carbon dots (CDs) are novel carbon-based luminescent materials with wide-ranging applications in biosensing, bioimaging, drug transportation, optical devices, and beyond. Their advantageous attributes, including biocompatibility, biodegradability, antioxidant activity, photostability, small particle size (< 10 nm), and strong light absorption and excitation across a broad range of wavelengths, making them promising candidates in the field of photodynamic therapy (PDT) as photosensitizers (PSs). Further enhancements in functionality are imperative to enhance the effectiveness of CDs in PDT applications, notwithstanding their inherent benefits. Recently, doping agents and solvents have been demonstrated to improve CDs' optical properties, solubility, cytotoxicity, and organelle targeting efficiency. These improvements result from modifications to the CDs' carbon skeleton matrices, functional groups on the surface state, and chemical structures. This review discusses the modification of CDs with heteroatom dopants, dye dopants, and solvents to improve their physicochemical and optical properties for PDT applications. The correlations between the surface chemistry, functional groups, structure of the CDs and their optical characteristics toward quantum yield, redshift feature and reactive oxygen species generation, have also been discussed. Finally, the progressive trends for the use of CDs in PDT applications are also addressed in this review.

7.
Langmuir ; 40(10): 5338-5347, 2024 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-38407060

RESUMEN

Herein, a low-cost and readily available sodium aluminate (NaAlO2) was used as a solid base catalyst for the depolymerization of polycarbonate (PC) via methanolysis in the presence of tetrahydrofuran (THF) as a solvent. NaAlO2 was highly active for the reaction, and the performance was comparable to that of soluble strong base SrO and much higher than those of MgO and CaO. By the reaction over the catalyst, a highly pure and crystalline bisphenol A (BPA) was obtained. Among tested organic solvents, THF was the best in aiding PC methanolysis over NaAlO2 due to the polarity similar to PC according to Hansen solubility parameters (HSPs). At 60 °C, 98.1% PC conversion and 96.8% BPA yield were achieved within just 2 h. NaAlO2 was reusable without any severe catalyst deactivation in at least four runs. The mechanistic study revealed that the reaction proceeded via the methoxide pathway, with THF aiding the dissolution of PC. The reaction over NaAlO2 possessed a low apparent activation energy (Ea) of 75.1 kJ mol-1, which is the lowest ever reported so far for the reaction over solid catalysts.

8.
Phys Chem Chem Phys ; 2024 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-39015995

RESUMEN

Quantum mechanics/molecular mechanics (QM/MM) simulations offer an efficient way to model reactions occurring in complex environments. This study introduces a specialized set of charge and Lennard-Jones parameters tailored for electrostatically embedded QM/MM calculations, aiming to accurately model both adsorption processes and catalytic reactions in zirconium-based metal-organic frameworks (Zr-MOFs). To validate our approach, we compare adsorption energies derived from QM/MM simulations against experimental results and Monte Carlo simulation outcomes. The developed parameters showcase the ability of QM/MM simulations to represent long-range electrostatic and van der Waals interactions faithfully. This capability is evidenced by the prediction of adsorption energies with a low root mean square error of 1.1 kcal mol-1 across a wide range of adsorbates. The practical applicability of our QM/MM model is further illustrated through the study of glucose isomerization and epimerization reactions catalyzed by two structurally distinct Zr-MOF catalysts, UiO-66 and MOF-808. Our QM/MM calculations closely align with experimental activation energies. Importantly, the parameter set introduced here is compatible with the widely used universal force field (UFF). Moreover, we thoroughly explore how the size of the cluster model and the choice of density functional theory (DFT) methodologies influence the simulation outcomes. This work provides an accurate and computationally efficient framework for modeling complex catalytic reactions within Zr-MOFs, contributing valuable insights into their mechanistic behaviors and facilitating further advancements in this dynamic area of research.

9.
Environ Res ; 250: 118519, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38382660

RESUMEN

The present study explores visible light-assisted photodegradation of ciprofloxacin hydrochloride (CIP) antibiotic as a promising solution to water pollution. The focus is on transforming the optical and electronic properties of BiOCl through the generation of oxygen vacancies (OVs) and the exposure of (110) facets, forming a robust S-scheme heterojunction with WS2. The resultant OVs mediated composite with an optimal ratio of WS2 and BiOCl-OV (4-WS2/BiOCl-OV) demonstrated remarkable efficiency (94.3%) in the visible light-assisted photodegradation of CIP antibiotic within 1.5 h. The CIP degradation using 4-WS2/BiOCl-OV followed pseudo-first-order kinetics with the rate constant of 0.023 min-1, outperforming bare WS2, BiOCl, and BiOCl-OV by 8, 6, and 4 times, respectively. Density functional theory (DFT) analysis aligned well with experimental results, providing insights into the structural arrangement and bandgap analysis of the photocatalysts. Liquid chromatography-mass spectrometry (LC-MS) analysis utilized for identifying potentially degraded products while scavenging experiments and electron paramagnetic resonance (EPR) spin trapping analysis elucidated the S-scheme charge transfer mechanism. This research contributes to advancing the design of oxygen vacancy-mediated S-scheme systems in the realm of photocatalysis, with potential implications for addressing water pollution concerns.


Asunto(s)
Ciprofloxacina , Oxígeno , Fotólisis , Aguas Residuales , Contaminantes Químicos del Agua , Ciprofloxacina/química , Contaminantes Químicos del Agua/química , Aguas Residuales/química , Oxígeno/química , Bismuto/química , Antibacterianos/química , Tungsteno/química , Catálisis , Luz , Teoría Funcional de la Densidad
10.
Proc Natl Acad Sci U S A ; 118(15)2021 04 13.
Artículo en Inglés | MEDLINE | ID: mdl-33827925

RESUMEN

Simultaneous profiling of multiomic modalities within a single cell is a grand challenge for single-cell biology. While there have been impressive technical innovations demonstrating feasibility-for example, generating paired measurements of single-cell transcriptome (single-cell RNA sequencing [scRNA-seq]) and chromatin accessibility (single-cell assay for transposase-accessible chromatin using sequencing [scATAC-seq])-widespread application of joint profiling is challenging due to its experimental complexity, noise, and cost. Here, we introduce BABEL, a deep learning method that translates between the transcriptome and chromatin profiles of a single cell. Leveraging an interoperable neural network model, BABEL can predict single-cell expression directly from a cell's scATAC-seq and vice versa after training on relevant data. This makes it possible to computationally synthesize paired multiomic measurements when only one modality is experimentally available. Across several paired single-cell ATAC and gene expression datasets in human and mouse, we validate that BABEL accurately translates between these modalities for individual cells. BABEL also generalizes well to cell types within new biological contexts not seen during training. Starting from scATAC-seq of patient-derived basal cell carcinoma (BCC), BABEL generated single-cell expression that enabled fine-grained classification of complex cell states, despite having never seen BCC data. These predictions are comparable to analyses of experimental BCC scRNA-seq data for diverse cell types related to BABEL's training data. We further show that BABEL can incorporate additional single-cell data modalities, such as protein epitope profiling, thus enabling translation across chromatin, RNA, and protein. BABEL offers a powerful approach for data exploration and hypothesis generation.


Asunto(s)
Carcinoma/genética , Genómica/métodos , Análisis de la Célula Individual/métodos , Programas Informáticos , Animales , Carcinoma/metabolismo , Aprendizaje Profundo , Humanos , Ratones , Proteoma/genética , Proteoma/metabolismo , Transcriptoma
11.
J Hand Surg Am ; 49(6): 511-525, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38530683

RESUMEN

PURPOSE: As osteoarthritis (OA) of the trapeziometacarpal (TMC) joint leads to a high degree of disease burden with compromises in rudimentary and fine movements of the hand, intra-articular injections may be a desirable treatment option. However, because there are no evidence-based guidelines, the choice of intra-articular injection type is left to the discretion of the individual surgeon in collaboration with the patient. The purpose of our study was to perform a systematic review and meta-analysis using level I studies to compare outcomes following corticosteroid and alternative methods of intra-articular injections for the management of TMC OA. Our hypothesis was that intra-articular corticosteroid injections were no more effective than other methods of intra-articular injections for the management of TMC OA. METHODS: A systematic literature search was performed. Eligible for inclusion were randomized control trials reporting on intra-articular corticosteroid injection for the management of TMC OA. Clinical outcomes were recorded. RESULTS: The 10 included studies comprised 673 patients. The mean age was 57.8 ± 8.3 years, with a mean follow-up of 6.4 ± 2.7 months. There was no significant difference in visual analog scale scores, grip strength and tip pinch strength between corticosteroids and hyaluronic acid at short- and medium-term follow-up. Further, there was no difference in visual analog scale pain scores at rest at medium-term follow-up between corticosteroids and platelet-rich plasma. CONCLUSIONS: Despite short-term improvement with intra-articular corticosteroid injections, there was no significant difference in pain and functional outcomes following intra-articular corticosteroid injections compared to hyaluronic acid or platelet-rich plasma administration. Given the affordability, ease of administration, and efficacy associated with corticosteroids, they are a favorable option when considering the choice of intra-articular injection for the management of TMC OA. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic II.


Asunto(s)
Corticoesteroides , Articulaciones Carpometacarpianas , Osteoartritis , Ensayos Clínicos Controlados Aleatorios como Asunto , Hueso Trapecio , Humanos , Inyecciones Intraarticulares , Osteoartritis/tratamiento farmacológico , Corticoesteroides/administración & dosificación , Ácido Hialurónico/administración & dosificación , Fuerza de la Mano , Resultado del Tratamiento
12.
Int J Mol Sci ; 25(3)2024 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-38338832

RESUMEN

Nonspecific orbital inflammation (NSOI), colloquially known as orbital pseudotumor, sometimes presents a diagnostic and therapeutic challenge in ophthalmology. This review aims to dissect NSOI through a molecular lens, offering a comprehensive overview of its pathogenesis, clinical presentation, diagnostic methods, and management strategies. The article delves into the underpinnings of NSOI, examining immunological and environmental factors alongside intricate molecular mechanisms involving signaling pathways, cytokines, and mediators. Special emphasis is placed on emerging molecular discoveries and approaches, highlighting the significance of understanding molecular mechanisms in NSOI for the development of novel diagnostic and therapeutic tools. Various diagnostic modalities are scrutinized for their utility and limitations. Therapeutic interventions encompass medical treatments with corticosteroids and immunomodulatory agents, all discussed in light of current molecular understanding. More importantly, this review offers a novel molecular perspective on NSOI, dissecting its pathogenesis and management with an emphasis on the latest molecular discoveries. It introduces an integrated approach combining advanced molecular diagnostics with current clinical assessments and explores emerging targeted therapies. By synthesizing these facets, the review aims to inform clinicians and researchers alike, paving the way for molecularly informed, precision-based strategies for managing NSOI.


Asunto(s)
Cristalino , Oftalmología , Seudotumor Orbitario , Humanos , Inflamación/diagnóstico , Inflamación/terapia , Seudotumor Orbitario/diagnóstico , Seudotumor Orbitario/patología , Cristalino/patología , Citocinas
13.
Molecules ; 29(10)2024 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-38792122

RESUMEN

The eye's complex anatomical structures present formidable barriers to effective drug delivery across a range of ocular diseases, from anterior to posterior segment pathologies. Emerging as a promising solution to these challenges, nanotechnology-based platforms-including but not limited to liposomes, dendrimers, and micelles-have shown the potential to revolutionize ophthalmic therapeutics. These nanocarriers enhance drug bioavailability, increase residence time in targeted ocular tissues, and offer precise, localized delivery, minimizing systemic side effects. Focusing on pediatric ophthalmology, particularly on retinoblastoma, this review delves into the recent advancements in functionalized nanosystems for drug delivery. Covering the literature from 2017 to 2023, it comprehensively examines these nanocarriers' potential impact on transforming the treatment landscape for retinoblastoma. The review highlights the critical role of these platforms in overcoming the unique pediatric eye barriers, thus enhancing treatment efficacy. It underscores the necessity for ongoing research to realize the full clinical potential of these innovative drug delivery systems in pediatric ophthalmology.


Asunto(s)
Sistemas de Liberación de Medicamentos , Retinoblastoma , Retinoblastoma/tratamiento farmacológico , Humanos , Portadores de Fármacos/química , Niño , Nanopartículas/química , Micelas , Liposomas/química , Dendrímeros/química , Neoplasias de la Retina/tratamiento farmacológico , Administración Oftálmica , Nanotecnología/métodos
14.
Aesthet Surg J ; 44(6): NP402-NP410, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38366708

RESUMEN

BACKGROUND: The ability to degrade hyaluronic acid (HA)-based fillers with hyaluronidase allows for better management of adverse effects and reversal of suboptimal treatment outcomes. OBJECTIVES: The aim of this study was to compare the enzymatic degradation kinetics of 16 commercially available HA-based fillers, representing 6 manufacturing technologies. METHODS: In this nonclinical study, a recently developed in vitro multidose hyaluronidase administration protocol was used to induce degradation of HA-based fillers, enabling real-time evaluation of viscoelastic properties under near-static conditions. Each filler was exposed to repeated doses of hyaluronidase at intervals of 5 minutes to reach the degradation threshold of G' ≤ 30 Pa. RESULTS: Noticeable differences in degradation characteristics were observed based on the design and technology of different filler classes. Vycross fillers were the most difficult to degrade and the Cohesive Polydensified Matrix filler was the least difficult to degrade. Preserved Network Technology products demonstrated proportional increases in gel degradation time and enzyme volume required for degradation across the individual resilient hyaluronic acid (RHA) products and indication categories. No obvious relationship was observed between gel degradation characteristics and the individual parameters of HA concentration, HA chain length, or the degree of modification of each filler when analyzed separately; however, a general correlation was identified with certain physicochemical properties. CONCLUSIONS: Manufacturing technology was the most important factor influencing the reversibility of an HA product. An understanding of the differential degradation profiles of commercially available fillers will allow clinicians to select products that offer a higher margin of safety due to their preferential reversibility.


Asunto(s)
Técnicas Cosméticas , Rellenos Dérmicos , Ácido Hialurónico , Hialuronoglucosaminidasa , Hialuronoglucosaminidasa/metabolismo , Hialuronoglucosaminidasa/química , Ácido Hialurónico/química , Ácido Hialurónico/administración & dosificación , Ácido Hialurónico/metabolismo , Rellenos Dérmicos/química , Rellenos Dérmicos/administración & dosificación , Cinética , Humanos , Ensayo de Materiales , Viscosidad , Elasticidad
15.
J Foot Ankle Surg ; 2024 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-39009279

RESUMEN

This systematic review and meta-analysis delved into the impact of race and ethnicity on outcomes following foot and ankle surgery, an area garnering increasing attention within the medical community. Despite significant literature on post-surgical clinical and functional outcomes, limited research has explored the influence of racial and ethnic factors on post-operative outcomes. In this study, data from 33 relevant studies, involving a total of 557,734 patients, were analyzed to assess outcomes across different racial and ethnic groups. Notably, only six studies met the criteria for inclusion in the final meta-analysis due to variations in outcome reporting. Findings revealed disparities in functional scores, pain levels, and resource utilization among different racial and ethnic cohorts. Specifically, non-White and minority patients exhibited higher rates of foot and ankle fractures and lower extremity surgeries, worse functional outcomes, increased pain, longer hospital stays, and a greater incidence of complications compared to their White counterparts. However, some studies presented contradictory results, emphasizing the necessity for further investigation to elucidate these discrepancies fully. This research underscores the importance of considering racial and ethnic factors in foot and ankle surgery outcomes and highlights the need for targeted interventions to address existing disparities.

16.
Foot Ankle Surg ; 2024 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-38637171

RESUMEN

BACKGROUND: As total ankle arthroplasty (TAA) increases in popularity nationwide for the management of end-stage arthritis, it is essential to understand ways to mitigate the risk of infection. Diabetes increases the risk of infection due to compromised immunity and impaired wound-healing mechanisms. However, there is limited research on how diabetic management, inclusive of medications and glucose control, may impact infection risks post-TAA. This study aims to demonstrate the impact of diabetic management on the occurrence of periprosthetic joint infection (PJI) following TAA. METHODS: This was a retrospective study of patients who underwent a TAA at a single academic institution from March 2002 to May 2022. Patients with diabetes who developed an intraarticular infection following TAA were propensity score matched (1:3) to diabetic patients who did not. Data collection included demographics, implant types, diabetic medications, and preoperative hemoglobin A1c. PJI was diagnosed based on Musculoskeletal Infection Society (MSIS) criteria. Statistical analyses assessed differences in medication use, glucose control, and infection rates between groups. RESULTS: Of the 1863 patients who underwent TAA, 177 patients had a diagnosis of diabetes. The infection rate in patients with diabetes (2.8%) was higher than the total cohort rate (0.8%). Five patients with diabetes developed a PJI at an average of 2.2 months postoperatively. This cohort (n = 5) was compared to propensity score-matched controls (n = 15). There was no significant difference in diabetic medication use. Patients who developed PJI had higher rates of uncontrolled diabetes (60.0% vs. 6.7%) and average A1c levels (7.02% vs. 6.29%) compared to controls. CONCLUSION: Our findings suggest that the elevated risk of PJI observed in individuals with diabetes subsequent to TAA may be attributed not solely to the presence of diabetes, but to inadequate glycemic control. Effectively managing blood glucose levels is imperative for achieving favorable outcomes following TAA. LEVEL OF EVIDENCE: III.

17.
Angew Chem Int Ed Engl ; : e202408375, 2024 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-38847272

RESUMEN

Designing a nanofluidic membrane with high selectivity and fast ion transport property is the key towards high-performance osmotic energy conversion. However, most of reported membranes can produce power density less than commercial benchmark (5 W/m2), due to the imbalance between ion selectivity and permeability. Here, we report a novel nanoarchitectured design of a heterogeneous membrane with an ultrathin and dense zirconium-based UiO-66-NH2 metal-organic framework (MOF) layer and a highly aligned and interconnected branched alumina nanochannel membrane. The design leads to a continuous trilayered pore structure of large geometry gradient in the sequence from angstrom-scale to nano-scale to sub-microscale, which enables the enhanced directional ion transport, and the angstrom-sized (~6.6-7 Å) UiO-66-NH2 windows render the membrane with high ion selectivity. Consequently, the novel heterogeneous membrane can achieve a high-performance power of ~8 W/m2 by mixing synthetic seawater and river water. The power density can be largely upgraded to an ultrahigh ~17.1 W/m2 along with ~48.5% conversion efficiency at a 50-fold KCl gradient. This work not only presents a new membrane design approach but also showcases the great potential of employing the zirconium-based MOF channels as ion-channel-mimetic membranes for highly efficient blue energy harvesting.

18.
Angew Chem Int Ed Engl ; 63(19): e202400509, 2024 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-38419352

RESUMEN

In 2001, our curiosity to understand the stereochemistry of C-H metalation with Pd prompted our first studies in Pd(II)-catalyzed asymmetric C-H activation (RSC Research appointment: 020 7451 2545, Grant: RG 36873, Dec. 2002). We identified four central challenges: 1. poor reactivity of simple Pd salts with native substrates; 2. few strategies to control site selectivity for remote C-H bonds; 3. the lack of chiral catalysts to achieve enantioselectivity via asymmetric C-H metalation, and 4. low practicality due to limited coupling partner scope and the use of specialized oxidants. These challenges necessitated new strategies in catalyst and reaction development. For reactivity, we developed approaches to enhance substrate-catalyst affinity together with novel bifunctional ligands which participate in and accelerate the C-H cleavage step. For site-selectivity, we introduced the concept of systematically modulating the distance and geometry between a directing template, catalyst, and substrate to selectively access remote C-H bonds. For enantioselectivity, we devised predictable stereomodels for catalyst-controlled enantioselective C-H activation based on the participation of bifunctional ligands. Finally, for practicality, we have developed varied catalytic manifolds for Pd(II) to accommodate diverse coupling partners while employing practical oxidants such as simple peroxides. These advances have culminated in numerous C-H activation reactions, setting the stage for broad industrial applications.

19.
J Biol Chem ; 298(8): 102251, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35835223

RESUMEN

The soil-dwelling bacterium Pseudomonas putida S16 can survive on nicotine as its sole carbon and nitrogen source. The enzymes nicotine oxidoreductase (NicA2) and pseudooxynicotine amine oxidase (Pnao), both members of the flavin-containing amine oxidase family, catalyze the first two steps in the nicotine catabolism pathway. Our laboratory has previously shown that, contrary to other members of its enzyme family, NicA2 is actually a dehydrogenase that uses a cytochrome c protein (CycN) as its electron acceptor. The natural electron acceptor for Pnao is unknown; however, within the P. putida S16 genome, pnao forms an operon with cycN and nicA2, leading us to hypothesize that Pnao may also be a dehydrogenase that uses CycN as its electron acceptor. Here we characterized the kinetic properties of Pnao and show that Pnao is poorly oxidized by O2, but can be rapidly oxidized by CycN, indicating that Pnao indeed acts as a dehydrogenase that uses CycN as its oxidant. Comparing steady-state kinetics with transient kinetic experiments revealed that product release primarily limits turnover by Pnao. We also resolved the crystal structure of Pnao at 2.60 Å, which shows that Pnao has a similar structural fold as NicA2. Furthermore, rigid-body docking of the structure of CycN with Pnao and NicA2 identified a potential conserved binding site for CycN on these two enzymes. Taken together, our results demonstrate that although Pnao and NicA2 show a high degree of similarity to flavin containing amine oxidases that use dioxygen directly, both enzymes are actually dehydrogenases.


Asunto(s)
Proteínas Bacterianas , Oxidorreductasas , Pseudomonas putida , Proteínas Bacterianas/metabolismo , Butanonas , Citocromos c/metabolismo , Flavinas/metabolismo , Cinética , Monoaminooxidasa/metabolismo , Nicotina/análogos & derivados , Nicotina/química , Oxidorreductasas/metabolismo , Pseudomonas putida/enzimología
20.
Pharmacogenomics J ; 23(4): 95-104, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-36966195

RESUMEN

Previous observational studies reported associations between non-steroidal anti-inflammatory drugs (NSAIDs) and major depressive disorder (MDD), however, these associations are often inconsistent and underlying biological mechanisms are still poorly understood. We conducted a two-sample Mendelian randomisation (MR) study to examine relationships between genetic variants and NSAID target gene expression or DNA methylation (DNAm) using publicly available expression, methylation quantitative trait loci (eQTL or mQTL) data and genetic variant-disease associations from genome-wide association studies (GWAS of MDD). We also assessed drug exposure using gene expression and DNAm levels of NSAID targets as proxies. Genetic variants were robustly adjusted for multiple comparisons related to gene expression, DNAm was used as MR instrumental variables and GWAS statistics of MDD as the outcome. A 1-standard deviation (SD) lower expression of NEU1 in blood was related to lower C-reactive protein (CRP) levels of -0.215 mg/L (95% confidence interval (CI): 0.128-0.426) and a decreased risk of MDD (odds ratio [OR] = 0.806; 95% CI: 0.735-0.885; p = 5.36 × 10-6). A concordant direction of association was also observed for NEU1 DNAm levels in blood and a risk of MDD (OR = 0.886; 95% CI: 0.836-0.939; p = 4.71 × 10-5). Further, the genetic variants associated with MDD were mediated by NEU1 expression via DNAm (ß = -0.519; 95% CI: -0.717 to -0.320256; p = 3.16 × 10-7). We did not observe causal relationships between inflammatory genetic marker estimations and MDD risk. Yet, we identified a concordant association of NEU1 messenger RNA and an adverse direction of association of higher NEU1 DNAm with MDD risk. These results warrant increased pharmacovigilance and further in vivo or in vitro studies to investigate NEU1 inhibitors or supplements for MDD.


Asunto(s)
Trastorno Depresivo Mayor , Humanos , Trastorno Depresivo Mayor/tratamiento farmacológico , Trastorno Depresivo Mayor/genética , Estudio de Asociación del Genoma Completo/métodos , Sitios de Carácter Cuantitativo/genética , Metilación de ADN/genética , Antiinflamatorios
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