Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 467
Filtrar
1.
Ophthalmology ; 2024 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-38986874

RESUMEN

PURPOSE: Vision loss associated with opacification of the cornea is one of the leading causes of blindness globally. However, the epidemiological data pertaining to the demographics, associated etiological causes and reduced vision in corneal opacity patients continue to be sparse. This study assesses the case frequencies, underlying etiologies, and vision outcomes in patients diagnosed with corneal opacity, in the United States. DESIGN: Retrospective cohort study PARTICIPANTS: Patients in the IRIS® Registry (Intelligent Research in Sight) who were diagnosed with corneal opacity between January 1st, 2013, and November 30th, 2020. METHODS: The IRIS Registry contains demographic and clinical data of 79,887,324 patients who presented to eye clinics during the study period. We identified patients with corneal opacity using International Classification of Disease (ICD) codes (ICD-9, and -10) of "371" (corneal scar) and "H17" (corneal opacity), respectively. The analyzed data included demographic parameters included age, sex, race, ethnicity, and geographical location. We evaluated clinical data including laterality, etiology, disease descriptors, and best-corrected visual acuity (VA) up to 1 year before the onset (± 30 days), at the time of diagnosis, and at one year following diagnosis (± 30 days). MAIN OUTCOME MEASURES: Case frequencies, etiology, and vision outcomes in patients diagnosed with corneal opacity. RESULTS: We identified 5,220,382 patients who were diagnosed with corneal opacity and scars using H17 (ICD-10) and 371.0 (ICD-9) codes over seven years. The case frequency of corneal opacity during the study period was 6,535 cases per 100,000 patients (6.5%). The mean age of the patients was 63.36±18.14 years and the majority were female (57.6%). In the cohort, 38.39% and 30.00% of patients had bilateral and unilateral corneal opacity, respectively. Most of the patients were White (69.13%), followed by Black or African American (6.84%), Asian (2.45%), American Indian or Alaska Native(0.34%), Native Hawaii or other Pacific Islander(0.19%). Among the patients with corneal opacity, 7.34% had Hispanic or Latino ethnicity. The primary etiologies associated with corneal opacity included corneal dystrophies (64.66%) followed by edema (18.25%), ulcer (7.78%), keratoconjunctivitis (7.18%), degeneration (5.62%), neovascularization (6.27%), and trauma (5.28%). Visual acuity of the patients significantly worsened due to corneal opacity (0.46±0.74 logMAR; ∼20/58 in Snellen) and did not improve to the baseline (0.37±0.68 logMAR, ∼20/46 in Snellen) post-management (0.43±0.77 logMAR, ∼20/54 in Snellen). The multiple linear regression analysis showed worse vision outcomes in females (compared to males), and Asian, Black or African American, and American Indian or Alaska Native (compared to White) patients. Additionally, worse vision outcomes were observed in patients with opacity associated with corneal malformation, degenerative disorders, edema, injury, and ulcer compared to those with hereditary corneal dystrophy. CONCLUSIONS: Our study shows that the corneal opacity was diagnosed in 6.5% of the patients in the IRIS Registry and it was primarily associated with corneal dystrophies. The final vision outcomes in corneal opacity patients were significantly worse compared to baseline. The worse vision outcomes were associated with sociodemographic differences that might be associated with disparities in access, utilization, and care patterns.

2.
Ophthalmology ; 2024 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-39033858

RESUMEN

IRIS (Intelligent Research in Sight) Registry Study showing that acute retinal necrosis cases treated with systemic antivirals alone vs combined with intravitreal antivirals or early vitrectomy had statistically similar outcomes at 6 and 12 months.

3.
Chem Sci ; 15(29): 11279-11286, 2024 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-39055008

RESUMEN

To clinically advance the growing arsenal of radiometals available to image and treat cancer, chelators with versatile binding properties are needed. Herein, we evaluated the ability of the py2[18]dieneN6 macrocycle PYTA to interchangeably bind and stabilize 225Ac3+, [177Lu]Lu3+, [111In]In3+ and [44Sc]Sc3+, a chemically diverse set of radionuclides that can be used complementarily for targeted alpha therapy, beta therapy, single-photon emission computed tomography (SPECT) imaging, and positron emission tomography (PET) imaging, respectively. Through NMR spectroscopy and X-ray diffraction, we show that PYTA possesses an unusual degree of flexibility for a macrocyclic chelator, undergoing dramatic conformational changes that enable it to optimally satisfy the disparate coordination properties of each metal ion. Subsequent radiolabeling studies revealed that PYTA quantitatively binds all 4 radiometals at room temperature in just minutes at pH 6. Furthermore, these complexes were found to be stable in human serum over 2 half-lives. These results surpass those obtained for 2 state-of-the-art chelators for nuclear medicine, DOTA and macropa. The stability of 225Ac-PYTA and [44Sc]Sc-PYTA, the complexes having the most disparity with respect to metal-ion size, was further probed in mice. The resulting PET images (44Sc) and ex vivo biodistribution profiles (44Sc and 225Ac) of the PYTA complexes differed dramatically from those of unchelated [44Sc]Sc3+ and 225Ac3+. These differences provide evidence that PYTA retains this size-divergent pair of radionuclides in vivo. Collectively, these studies establish PYTA as a new workhorse chelator for nuclear medicine and warrant its further investigation in targeted constructs.

4.
Org Biomol Chem ; 2024 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-38973457

RESUMEN

Conjugates of benzothiophene-fused azacyclononyne BT9N-NH2 with fluorescent dyes were developed to visualise azidoglycans intracellularly. The significance of the cycloalkyne core was demonstrated by comparing new reagents with DBCO- and BCN-dye conjugates. To reduce non-specificity during intracellular bioconjugation using SPAAC, less reactive BT9N-dye reagents are preferred over highly reactive DBCO- and BCN-dye conjugates.

5.
Cells ; 13(13)2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38994986

RESUMEN

Biogenic polyamines are ubiquitous compounds. Dysregulation of their metabolism is associated with the development of various pathologies, including cancer, hyperproliferative diseases, and infections. The canonical pathway of polyamine catabolism includes acetylation of spermine and spermidine and subsequent acetylpolyamine oxidase (PAOX)-mediated oxidation of acetylpolyamines (back-conversion) or their direct efflux from the cell. PAOX is considered to catalyze a non-rate-limiting catabolic step. Here, we show that PAOX transcription levels are extremely low in various tumor- and non-tumor cell lines and, in most cases, do not change in response to altered polyamine metabolism. Its enzymatic activity is undetectable in the majority of cell lines except for neuroblastoma and low passage glioblastoma cell lines. Treatment of A549 cells with N1,N11-diethylnorspermine leads to PAOX induction, but its contribution to polyamine catabolism remains moderate. We also describe two alternative enzyme isoforms and show that isoform 4 has diminished oxidase activity and isoform 2 is inactive. PAOX overexpression correlates with the resistance of cancer cells to genotoxic antitumor drugs, indicating that PAOX may be a useful therapeutic target. Finally, PAOX is dispensable for the replication of various viruses. These data suggest that a decrease in polyamine levels is achieved predominantly by the secretion of acetylated spermine and spermidine rather than by back-conversion.


Asunto(s)
Oxidorreductasas actuantes sobre Donantes de Grupo CH-NH , Poliaminas , Humanos , Oxidorreductasas actuantes sobre Donantes de Grupo CH-NH/metabolismo , Oxidorreductasas actuantes sobre Donantes de Grupo CH-NH/genética , Poliaminas/metabolismo , Línea Celular Tumoral , Espermina/metabolismo , Espermina/análogos & derivados , Acetilación , Células A549
6.
Cardiovasc Digit Health J ; 5(3): 115-121, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38989042

RESUMEN

Background: Fatal coronary heart disease (FCHD) is often described as sudden cardiac death (affects >4 million people/year), where coronary artery disease is the only identified condition. Electrocardiographic artificial intelligence (ECG-AI) models for FCHD risk prediction using ECG data from wearable devices could enable wider screening/monitoring efforts. Objectives: To develop a single-lead ECG-based deep learning model for FCHD risk prediction and assess concordance between clinical and Apple Watch ECGs. Methods: An FCHD single-lead ("lead I" from 12-lead ECGs) ECG-AI model was developed using 167,662 ECGs (50,132 patients) from the University of Tennessee Health Sciences Center. Eighty percent of the data (5-fold cross-validation) was used for training and 20% as a holdout. Cox proportional hazards (CPH) models incorporating ECG-AI predictions with age, sex, and race were also developed. The models were tested on paired clinical single-lead and Apple Watch ECGs from 243 St. Jude Lifetime Cohort Study participants. The correlation and concordance of the predictions were assessed using Pearson correlation (R), Spearman correlation (ρ), and Cohen's kappa. Results: The ECG-AI and CPH models resulted in AUC = 0.76 and 0.79, respectively, on the 20% holdout and AUC = 0.85 and 0.87 on the Atrium Health Wake Forest Baptist external validation data. There was moderate-strong positive correlation between predictions (R = 0.74, ρ = 0.67, and κ = 0.58) when tested on the 243 paired ECGs. The clinical (lead I) and Apple Watch predictions led to the same low/high-risk FCHD classification for 99% of the participants. CPH prediction correlation resulted in an R = 0.81, ρ = 0.76, and κ = 0.78. Conclusion: Risk of FCHD can be predicted from single-lead ECGs obtained from wearable devices and are statistically concordant with lead I of a 12-lead ECG.

7.
J Am Chem Soc ; 2024 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-39042490

RESUMEN

Uranium is arguably the most essential element in the actinide series, serving as a crucial component of nuclear fuels. While U is recognized for engaging the 5f orbitals in chemical bonds under normal conditions, little is known about its coordination chemistry and the nature of bonding interactions at extreme conditions of high temperature. Here we report experimental and computational evidence for the shrinkage of the average U-ligand distance in UCl3 upon the solid-to-molten phase transition, leading to the formation of a significant fraction of short, transient U-Cl bonds with the enhanced involvement of U 5f valence orbitals. These findings reveal that extreme temperatures create an unusual heterogeneous bonding environment around U(III) with distinct inner- and outer-coordination subshells.

8.
Cells ; 13(12)2024 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-38920664

RESUMEN

Hepatitis C virus (HCV) is an oncogenic virus that causes chronic liver disease in more than 80% of patients. During the last decade, efficient direct-acting antivirals were introduced into clinical practice. However, clearance of the virus does not reduce the risk of end-stage liver diseases to the level observed in patients who have never been infected. So, investigation of HCV pathogenesis is still warranted. Virus-induced changes in cell metabolism contribute to the development of HCV-associated liver pathologies. Here, we studied the impact of the virus on the metabolism of polyamines and proline as well as on the urea cycle, which plays a crucial role in liver function. It was found that HCV strongly suppresses the expression of arginase, a key enzyme of the urea cycle, leading to the accumulation of arginine, and up-regulates proline oxidase with a concomitant decrease in proline concentrations. The addition of exogenous proline moderately suppressed viral replication. HCV up-regulated transcription but suppressed protein levels of polyamine-metabolizing enzymes. This resulted in a decrease in polyamine content in infected cells. Finally, compounds targeting polyamine metabolism demonstrated pronounced antiviral activity, pointing to spermine and spermidine as compounds affecting HCV replication. These data expand our understanding of HCV's imprint on cell metabolism.


Asunto(s)
Hepacivirus , Poliaminas , Prolina , Urea , Replicación Viral , Prolina/metabolismo , Humanos , Hepacivirus/fisiología , Hepacivirus/efectos de los fármacos , Poliaminas/metabolismo , Urea/metabolismo , Urea/farmacología , Replicación Viral/efectos de los fármacos , Arginasa/metabolismo , Antivirales/farmacología , Antivirales/metabolismo , Hepatitis C/metabolismo , Hepatitis C/virología , Línea Celular Tumoral , Prolina Oxidasa/metabolismo
9.
Photosynth Res ; 161(1-2): 51-64, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38865029

RESUMEN

Photostasis is the light-dependent maintenance of energy balance associated with cellular homeostasis in photoautotrophs. We review evidence that illustrates how photosynthetic adaptation in polar photoautrophs such as aquatic green algae, cyanobacteria, boreal conifers as well as terrestrial angiosperms exhibit an astonishing plasticity in structure and function of the photosynthetic apparatus. This plasticity contributes to the maintenance of photostasis, which is essential for the long-term survival in the seemingly inhospitable Antarctic and Arctic habitats. However, evidence indicates that polar photoautrophic species exhibit different functional solutions for the maintenance of photostasis. We suggest that this reflects, in part, the genetic diversity symbolized by inherent genetic redundancy characteristic of polar photoautotrophs which enhances their survival in a thermodynamically challenging environment.


Asunto(s)
Adaptación Fisiológica , Fotosíntesis , Fotosíntesis/fisiología , Regiones Árticas , Regiones Antárticas , Cianobacterias/fisiología , Cianobacterias/genética , Chlorophyta/fisiología , Chlorophyta/genética , Ecosistema , Luz , Magnoliopsida/fisiología , Magnoliopsida/genética , Tracheophyta/fisiología , Tracheophyta/genética
10.
Molecules ; 29(12)2024 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-38930858

RESUMEN

The preparation and application of the composite material "crosslinked polyvinyl alcohol-magnetite" as a sensitive matrix for use in digital colorimetry and optical micrometry methods are discussed. The material was synthesized in the form of spherical granules (for micrometry) and thin films (for digital colorimetry). The obtained composites were characterized by the registration of magnetization curves. It was shown that the amount of grown Fe3O4 particles in the polymer gel is in linear dependence with the iron salt concentrations in the impregnating solutions. The composite granules were applied to determining monosaccharides using optical micrometry. The optimal pH value for the total amount of monosaccharides' determination was 8.6. The study of the analytical response of composite granules and films performed with a low limit of detection (7.9 mmol/dm3) of both glucose and fructose and a possibility of the control of high alcohol contention in water media. The granules were used to determine the total carbohydrate content in samples of natural honey and syrups with high fructose contents, while the films were used to control the alcohol content in hand antiseptics. The results obtained are in good agreement with the data provided by the manufacturers.

11.
Int J Mol Sci ; 25(12)2024 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-38928340

RESUMEN

Papain-like protease PLpro, a domain within a large polyfunctional protein, nsp3, plays key roles in the life cycle of SARS-CoV-2, being responsible for the first events of cleavage of a polyprotein into individual proteins (nsp1-4) as well as for the suppression of cellular immunity. Here, we developed a new genetically encoded fluorescent sensor, named PLpro-ERNuc, for detection of PLpro activity in living cells using a translocation-based readout. The sensor was designed as follows. A fragment of nsp3 protein was used to direct the sensor on the cytoplasmic surface of the endoplasmic reticulum (ER) membrane, thus closely mimicking the natural target of PLpro. The fluorescent part included two bright fluorescent proteins-red mScarlet I and green mNeonGreen-separated by a linker with the PLpro cleavage site. A nuclear localization signal (NLS) was attached to ensure accumulation of mNeonGreen into the nucleus upon cleavage. We tested PLpro-ERNuc in a model of recombinant PLpro expressed in HeLa cells. The sensor demonstrated the expected cytoplasmic reticular network in the red and green channels in the absence of protease, and efficient translocation of the green signal into nuclei in the PLpro-expressing cells (14-fold increase in the nucleus/cytoplasm ratio). Then, we used PLpro-ERNuc in a model of Huh7.5 cells infected with the SARS-CoV-2 virus, where it showed robust ER-to-nucleus translocation of the green signal in the infected cells 24 h post infection. We believe that PLpro-ERNuc represents a useful tool for screening PLpro inhibitors as well as for monitoring virus spread in a culture.


Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/metabolismo , Células HeLa , COVID-19/virología , COVID-19/diagnóstico , COVID-19/metabolismo , Retículo Endoplásmico/metabolismo , Retículo Endoplásmico/virología , Proteasas Similares a la Papaína de Coronavirus/metabolismo , Proteínas Luminiscentes/metabolismo , Proteínas Luminiscentes/genética , Proteasas 3C de Coronavirus/metabolismo , Transporte de Proteínas , Técnicas Biosensibles/métodos
12.
J Nanobiotechnology ; 22(1): 306, 2024 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-38825717

RESUMEN

Targeted alpha therapy (TAT) relies on chemical affinity or active targeting using radioimmunoconjugates as strategies to deliver α-emitting radionuclides to cancerous tissue. These strategies can be affected by transmetalation of the parent radionuclide by competing ions in vivo and the bond-breaking recoil energy of decay daughters. The retention of α-emitting radionuclides and the dose delivered to cancer cells are influenced by these processes. Encapsulating α-emitting radionuclides within nanoparticles can help overcome many of these challenges. Poly(lactic-co-glycolic acid) (PLGA) nanoparticles are a biodegradable and biocompatible delivery platform that has been used for drug delivery. In this study, PLGA nanoparticles are utilized for encapsulation and retention of actinium-225 ([225Ac]Ac3+). Encapsulation of [225Ac]Ac3+ within PLGA nanoparticles (Zave = 155.3 nm) was achieved by adapting a double-emulsion solvent evaporation method. The encapsulation efficiency was affected by both the solvent conditions and the chelation of [225Ac]Ac3+. Chelation of [225Ac]Ac3+ to a lipophilic 2,9-bis-lactam-1,10-phenanthroline ligand ([225Ac]AcBLPhen) significantly decreased its release (< 2%) and that of its decay daughters (< 50%) from PLGA nanoparticles. PLGA nanoparticles encapsulating [225Ac]AcBLPhen significantly increased the delivery of [225Ac]Ac3+ to murine (E0771) and human (MCF-7 and MDA-MB-231) breast cancer cells with a concomitant increase in cell death over free [225Ac]Ac3+ in solution. These results demonstrate that PLGA nanoparticles have potential as radionuclide delivery platforms for TAT to advance precision radiotherapy for cancer. In addition, this technology offers an alternative use for ligands with poor aqueous solubility, low stability, or low affinity, allowing them to be repurposed for TAT by encapsulation within PLGA nanoparticles.


Asunto(s)
Actinio , Nanopartículas , Copolímero de Ácido Poliláctico-Ácido Poliglicólico , Nanopartículas/química , Copolímero de Ácido Poliláctico-Ácido Poliglicólico/química , Actinio/química , Humanos , Línea Celular Tumoral , Animales , Partículas alfa/uso terapéutico , Ratones , Femenino , Materiales Biocompatibles/química , Neoplasias de la Mama/tratamiento farmacológico , Radioinmunoterapia/métodos
13.
Methods Mol Biol ; 2817: 19-31, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38907144

RESUMEN

Clinical and biological samples are often scarce and precious (e.g., rare cell isolates, microneedle tissue biopsies, small-volume liquid biopsies, and even single cells or organelles). Typical large-scale proteomic methods, where significantly higher protein amounts are analyzed, are not directly transferable to the analysis of limited samples due to their incompatibility with pg-, ng-, and low-µg-level protein sample amounts. Here, we report the on-microsolid-phase extraction tip (OmSET)-based sample preparation workflow for sensitive analysis of limited biological samples to address this challenge. The developed platform was successfully tested for the analysis of 100-10,000 typical mammalian cells and is scalable to allow for lower and larger protein amounts and more samples to be analyzed (i.e., higher throughput of analysis).


Asunto(s)
Proteómica , Extracción en Fase Sólida , Flujo de Trabajo , Proteómica/métodos , Humanos , Extracción en Fase Sólida/métodos , Proteínas/análisis , Proteoma/análisis
14.
J Proteome Res ; 23(6): 2230-2240, 2024 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-38690845

RESUMEN

Deep proteomic profiling of complex biological and medical samples available at low nanogram and subnanogram levels is still challenging. Thorough optimization of settings, parameters, and conditions in nanoflow liquid chromatography-tandem mass spectrometry (MS)-based proteomic profiling is crucial for generating informative data using amount-limited samples. This study demonstrates that by adjusting selected instrument parameters, e.g., ion injection time, automated gain control, and minimally altering the conditions for resuspending or storing the sample in solvents of different compositions, up to 15-fold more thorough proteomic profiling can be achieved compared to conventionally used settings. More specifically, the analysis of 1 ng of the HeLa protein digest standard by Q Exactive HF-X Hybrid Quadrupole-Orbitrap and Orbitrap Fusion Lumos Tribrid mass spectrometers yielded an increase from 1758 to 5477 (3-fold) and 281 to 4276 (15-fold) peptides, respectively, demonstrating that higher protein identification results can be obtained using the optimized methods. While the instruments applied in this study do not belong to the latest generation of mass spectrometers, they are broadly used worldwide, which makes the guidelines for improving performance desirable to a wide range of proteomics practitioners.


Asunto(s)
Proteómica , Espectrometría de Masas en Tándem , Proteómica/métodos , Humanos , Espectrometría de Masas en Tándem/métodos , Células HeLa , Cromatografía Liquida/métodos , Proteoma/análisis , Péptidos/análisis , Péptidos/química
15.
J Extracell Biol ; 3(3)2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38751711

RESUMEN

Extracellular vesicles (EVs) play a pivotal role in various biological pathways, such as immune responses and the progression of diseases, including cancer. However, it is challenging to isolate EVs at high purity from blood plasma and other biofluids due to their low abundance compared to more predominant biomolecular species such as lipoprotein particles and free protein complexes. Ultracentrifugation-based EV isolation, the current gold standard technique, cannot overcome this challenge due to the similar biophysical characteristics of such species. We developed several novel approaches to enrich EVs from plasma while depleting contaminating molecular species using multimode chromatography-based strategies. On average, we identified 716 ± 68 and 1054 ± 35 protein groups in EV isolates from 100 µL of plasma using multimode chromatography- and ultracentrifugation-based techniques, respectively. The developed methods resulted in similar EV isolates purity, providing significant advantages in simplicity, throughput, scalability, and applicability for various downstream analytical and potential clinical applications.

16.
Nature ; 629(8013): 819-823, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38778232

RESUMEN

Lanthanide rare-earth metals are ubiquitous in modern technologies1-5, but we know little about chemistry of the 61st element, promethium (Pm)6, a lanthanide that is highly radioactive and inaccessible. Despite its importance7,8, Pm has been conspicuously absent from the experimental studies of lanthanides, impeding our full comprehension of the so-called lanthanide contraction phenomenon: a fundamental aspect of the periodic table that is quoted in general chemistry textbooks. Here we demonstrate a stable chelation of the 147Pm radionuclide (half-life of 2.62 years) in aqueous solution by the newly synthesized organic diglycolamide ligand. The resulting homoleptic PmIII complex is studied using synchrotron X-ray absorption spectroscopy and quantum chemical calculations to establish the coordination structure and a bond distance of promethium. These fundamental insights allow a complete structural investigation of a full set of isostructural lanthanide complexes, ultimately capturing the lanthanide contraction in solution solely on the basis of experimental observations. Our results show accelerated shortening of bonds at the beginning of the lanthanide series, which can be correlated to the separation trends shown by diglycolamides9-11. The characterization of the radioactive PmIII complex in an aqueous environment deepens our understanding of intra-lanthanide behaviour12-15 and the chemistry and separation of the f-block elements16.

17.
Nat Commun ; 15(1): 3847, 2024 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-38719792

RESUMEN

The development of reliable single-cell dispensers and substantial sensitivity improvement in mass spectrometry made proteomic profiling of individual cells achievable. Yet, there are no established methods for single-cell glycome analysis due to the inability to amplify glycans and sample losses associated with sample processing and glycan labeling. In this work, we present an integrated platform coupling online in-capillary sample processing with high-sensitivity label-free capillary electrophoresis-mass spectrometry for N-glycan profiling of single mammalian cells. Direct and unbiased quantitative characterization of single-cell surface N-glycomes are demonstrated for HeLa and U87 cells, with the detection of up to 100 N-glycans per single cell. Interestingly, N-glycome alterations are unequivocally detected at the single-cell level in HeLa and U87 cells stimulated with lipopolysaccharide. The developed workflow is also applied to the profiling of ng-level amounts (5-500 ng) of blood-derived protein, extracellular vesicle, and total plasma isolates, resulting in over 170, 220, and 370 quantitated N-glycans, respectively.


Asunto(s)
Electroforesis Capilar , Glicómica , Espectrometría de Masas , Polisacáridos , Análisis de la Célula Individual , Humanos , Electroforesis Capilar/métodos , Polisacáridos/metabolismo , Polisacáridos/sangre , Análisis de la Célula Individual/métodos , Células HeLa , Espectrometría de Masas/métodos , Glicómica/métodos , Proteómica/métodos , Vesículas Extracelulares/metabolismo , Lipopolisacáridos , Proteínas Sanguíneas/análisis , Proteínas Sanguíneas/metabolismo
18.
Small ; : e2401798, 2024 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-38700074

RESUMEN

The covalent organic frameworks (COFs) possessing high crystallinity and capability to capture low-concentration CO2 (400 ppm) from air are still underdeveloped. The challenge lies in simultaneously incorporating high-density active sites for CO2 insertion and maintaining the ordered structure. Herein, a structure engineering approach is developed to afford an ionic pair-functionalized crystalline and stable fluorinated COF (F-COF) skeleton. The ordered structure of the F-COF is well maintained after the integration of abundant basic fluorinated alcoholate anions, as revealed by synchrotron X-ray scattering experiments. The breakthrough test demonstrates its attractive performance in capturing (400 ppm) CO2 from gas mixtures via O─C bond formation, as indicated by the in situ spectroscopy and operando nuclear magnetic resonance spectroscopy using 13C-labeled CO2 sources. Both theoretical and experimental thermodynamic studies reveal the reaction enthalpy of ≈-40 kJ mol-1 between CO2 and the COF scaffolds. This implies weaker interaction strength compared with state-of-the-art amine-derived sorbents, thus allowing complete CO2 release with less energy input. The structure evolution study from synchrotron X-ray scattering and small-angle neutron scattering confirms the well-maintained crystalline patterns after CO2 insertion. The as-developed proof-of-concept approach provides guidance on anchoring binding sites for direct air capture (DAC) of CO2 in crystalline scaffolds.

20.
J Phys Chem B ; 128(16): 3972-3980, 2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38624173

RESUMEN

Complex molten chloride salt mixtures of uranium, magnesium, and sodium are top candidates for promising nuclear energy technologies to produce electricity based on molten salt reactors. From a local structural perspective, LaCl3 is similar to UCl3 and hence a good proxy to study these complex salt mixtures. As fission products, lanthanide salts and their mixtures are also very important in their own right. This article describes from an experimental and theory perspective how very different the structural roles of MgCl2 and NaCl are in mixtures with LaCl3. We find that, whereas MgCl2 becomes an integral part of multivalent ionic networks, NaCl separates them. In a recent article (J. Am. Chem. Soc. 2022, 144, 21751-21762) we have called the disruptive behavior of NaCl "the spacer salt effect". Because of the heterogeneous nature of these salt mixtures, there are multiple structural motifs in the melt, each with its particular free energetics. Our work identifies and quantifies these; it also elucidates the mechanisms through which Cl- ions exchange between Mg2+-rich and La3+-rich environments.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...