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1.
Nat Chem Biol ; 19(1): 45-54, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36138140

RESUMEN

Clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 13 (Cas13) has been rapidly developed for nucleic-acid-based diagnostics by using its characteristic collateral activity. Despite the recent progress in optimizing the Cas13 system for the detection of nucleic acids, engineering Cas13 protein with enhanced collateral activity has been challenging, mostly because of its complex structural dynamics. Here we successfully employed a novel strategy to engineer the Leptotrichia wadei (Lwa)Cas13a by inserting different RNA-binding domains into a unique active-site-proximal loop within its higher eukaryotes and prokaryotes nucleotide-binding domain. Two LwaCas13a variants showed enhanced collateral activity and improved sensitivity over the wild type in various buffer conditions. By combining with an electrochemical method, our variants detected the SARS-CoV-2 genome at attomolar concentrations from both inactive viral and unextracted clinical samples, without target preamplification. Our engineered LwaCas13a enzymes with enhanced collateral activity are ready to be integrated into other Cas13a-based platforms for ultrasensitive detection of nucleic acids.


Asunto(s)
COVID-19 , Ácidos Nucleicos , Humanos , SARS-CoV-2/genética , Ácidos Nucleicos/genética , Genoma , Sistemas CRISPR-Cas/genética
2.
Cereb Cortex ; 34(1)2024 01 14.
Artículo en Inglés | MEDLINE | ID: mdl-38100358

RESUMEN

Mutual prediction is crucial for understanding the mediation of bodily actions in social interactions. Despite this importance, limited studies have investigated neurobehavioral patterns under the mutual prediction hypothesis in natural competitive scenarios. To address this gap, our study employed functional near-infrared spectroscopy hyperscanning to examine the dynamics of real-time rock-paper-scissors games using a computerized paradigm with 54 participants. Firstly, our results revealed activations in the right inferior frontal gyrus, bilateral dorsolateral prefrontal cortex, and bilateral frontopolar cortex, each displaying distinct temporal profiles indicative of diverse cognitive processes during the task. Subsequently, a task-related increase in inter-brain synchrony was explicitly identified in the right dorsolateral prefrontal cortex, which supported the mutual prediction hypothesis across the two brains. Moreover, our investigation uncovered a close association between the coherence value in the right dorsolateral prefrontal cortex and the dynamic predictive performances of dyads using inter-subject representational similarity analysis. Finally, heightened inter-brain synchrony values were observed in the right dorsolateral prefrontal cortex before a draw compared to a no-draw scenario in the second block, suggesting that cross-brain signal patterns could be reflected in behavioral responses during competition. In summary, these findings provided initial support for expanding the understanding of cognitive processes underpinning natural competitive engagements.


Asunto(s)
Conducta Cooperativa , Espectroscopía Infrarroja Corta , Humanos , Espectroscopía Infrarroja Corta/métodos , Encéfalo/diagnóstico por imagen , Encéfalo/fisiología , Corteza Prefrontal/diagnóstico por imagen , Corteza Prefrontal/fisiología , Corteza Cerebral , Mapeo Encefálico/métodos , Relaciones Interpersonales
3.
Nano Lett ; 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38968148

RESUMEN

Repolarizing tumor-associated macrophages (TAMs) into tumor-inhibiting M1 macrophages has been considered a promising strategy for enhanced cancer immunotherapy. However, several immunosuppressive ligands (e.g., LSECtin) can still be highly expressed on M1 macrophages, inducing unsatisfactory therapeutic outcomes. We herein developed an antibody-decorated nanoplatform composed of PEGylated iron oxide nanoparticles (IONPs) and LSECtin antibody conjugated onto the surface of IONPs via the hydrazone bond for enhanced cancer immunotherapy. After intravenous administration, the tumor microenvironment (TME) pH could trigger the hydrazone bond breakage and induce the disassociation of the nanoplatform into free LSECtin antibodies and IONPs. Consequently, the IONPs could repolarize TAMs into M1 macrophages to remodel immunosuppressive TME and provide an additional anticancer effect via secreting tumoricidal factors (e.g., interlukin-12). Meanwhile, the LSECtin antibody could further block the activity of LSECtin expressed on M1 macrophages and relieve its immunosuppressive effect on CD8+ T cells, ultimately leading to significant inhibition of tumor growth.

4.
Nano Lett ; 24(9): 2727-2734, 2024 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-38395052

RESUMEN

Noncolinear spin textures, including chiral stripes and skyrmions, have shown great potential in spintronics. Basic configurations of spin textures are either Bloch or Néel types, and the intermediate hybrid type has rarely been reported. A major challenge in identifying hybrid spin textures is to quantitatively determine the hybrid angle, especially in ferrimagnets with weak net magnetization. Here, we develop an approach to quantify magnetic parameters, including chirality, saturation magnetization, domain wall width, and hybrid angle with sub-5 nm spatial resolution, based on Lorentz four-dimensional scanning transmission electron microscopy (Lorentz 4D-STEM). We find strong nanometer-scale variations in the hybrid angle and domain wall width within structurally and chemically homogeneous FeGd ferrimagnetic films. These variations fluctuate during different magnetization circles, revealing intrinsic local magnetization inhomogeneities. Furthermore, hybrid skyrmions can also be nucleated in FeGd films. These analyses demonstrate that the Lorentz 4D-STEM is a quantitative tool for exploring complex spin textures.

5.
Nano Lett ; 24(5): 1544-1552, 2024 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-38270095

RESUMEN

Lithium-metal (Li0) anodes potentially enable all-solid-state batteries with high energy density. However, it shows incompatibility with sulfide solid-state electrolytes (SEs). One strategy is introducing an interlayer, generally made of a mixed ionic-electronic conductor (MIEC). Yet, how Li behaves within MIEC remains unknown. Herein, we investigated the Li dynamics in a graphite interlayer, a typical MIEC, by using operando neutron imaging and Raman spectroscopy. This study revealed that intercalation-extrusion-dominated mechanochemical reactions during cell assembly transform the graphite into a Li-graphite interlayer consisting of SE, Li0, and graphite-intercalation compounds. During charging, Li+ preferentially deposited at the Li-graphite|SE interface. Upon further plating, Li0-dendrites formed, inducing short circuits and the reverse migration of Li0. Modeling indicates the interface has the lowest nucleation barrier, governing lithium transport paths. Our study elucidates intricate mechano-chemo-electrochemical processes in mixed conducting interlayers. The behavior of Li+ and Li0 in the interlayer is governed by multiple competing factors.

6.
Small ; 20(10): e2305923, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37919865

RESUMEN

Emerging evidence has demonstrated the significant contribution of mitochondrial metabolism dysfunction to promote cancer development and progression. Aberrant expression of mitochondrial genome (mtDNA)-encoded proteins widely involves mitochondrial metabolism dysfunction, and targeted regulation of their expression can be an effective strategy for cancer therapy, which however is challenged due to the protection by the mitochondrial double membrane. Herein, a mitochondria-targeted RNAi nanoparticle (NP) platform for effective regulation of mitochondrial metabolism and breast cancer (BCa) therapy is developed. This nanoplatform is composed of a hydrophilic polyethylene glycol (PEG) shell, a hydrophobic poly(2-(diisopropylamino)ethyl methacrylate) (PDPA) core, and charged-mediated complexes of mitochondria-targeting and membrane-penetrating peptide amphiphile (MMPA) and small interfering RNA (siRNA) embedded in the core. After tumor accumulation and internalization by tumor cells, these NPs can respond to the endosomal pH to expose the MMPA/siRNA complexes, which can specifically transport siRNA into the mitochondria to down-regulate mtDNA-encoded protein expression (e.g., ATP6 and CYB). More importantly, because ATP6 down-regulation can suppress ATP production and enhance reactive oxygen species (ROS) generation to induce mitochondrial damage and mtDNA leakage into tumor tissues, the NPs can combinatorially inhibit tumor growth via suppressing ATP production and repolarizing tumor-associated macrophages (TAMs) into tumor-inhibiting M1-like macrophages by mtDNA.


Asunto(s)
Neoplasias de la Mama , Nanopartículas , Propionatos , Compuestos de Sulfhidrilo , Humanos , Femenino , Interferencia de ARN , Neoplasias de la Mama/patología , ARN Interferente Pequeño/genética , Nanopartículas/química , Péptidos/metabolismo , Mitocondrias/metabolismo , ADN Mitocondrial , Adenosina Trifosfato , Línea Celular Tumoral
7.
Small ; : e2306714, 2024 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-38396320

RESUMEN

The blood-brain barrier (BBB) contains tightly connected brain microvascular endothelial cells (BMECs) that hinder drug delivery to the brain, which makes brain tumors difficult to treat. Previous studies have shown that nanoparticles coated with tumor cell membranes selectively target their homologous tumors. Therefore, this study investigated whether bEnd.3-line BMEC membrane-coated nanoparticles with poly(lactide-co-glycolide)-poly(ethylene glycol)-based doxorubicin-loaded cores (BM-PDs) can be used to target BMECs and cross the BBB. In vitro, the BM-PDs effectively target BMECs and cross a BBB model. The BM-PDs enter the BMECs via macropinocytosis, clathrin-mediated endocytosis, caveolin-mediated endocytosis, and membrane fusion, which result in excellent cellular uptake. The BM-PDs also show excellent cellular uptake in brain tumor cells. In vivo, the BM-PDs target BMECs, cross the BBB, accumulate in brain tumors, and efficiently kill tumor cells. Therefore, the proposed strategy has great therapeutic potential owing to its ability to cross the BBB to reach brain tumors.

8.
Small ; 20(15): e2306364, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37997202

RESUMEN

Sonodynamic therapy (SDT) offers a remarkable non-invasive ultrasound (US) treatment by activating sonosensitizer and generating reactive oxygen species (ROS) to inhibit tumor growth. The development of multifunctional, biocompatible, and highly effective sonosensitizers remains a current priority for SDT. Herein, the first report that Mn(II) ions chelated Gd-TCPP (GMT) nanosheets (NSs) are synthesized via a simple reflux method and encapsulated with pluronic F-127 to form novel sonosensitizers (GMTF). The GMTF NSs produce a high yield of ROS under US irradiation due to the decreased highest occupied molecular orbital-lowest unoccupied molecular orbital gap energy (2.7-1.28 eV). Moreover, Mn(II) ions endow GMTF with a fascinating Fenton-like activity to produce hydroxyl radicals in support of chemodynamic therapy (CDT). It is also effectively used in magnetic resonance imaging (MRI) with high relaxation rate (r 1: 4.401 mM-1 s-1) to track the accumulation of NSs in tumors. In vivo results indicate that the SDT and CDT in combination with programmed cell death protein 1 antibody (anti-PD-1) show effective metastasis prevention effects, and 70% of the mice in the GMTF + US + anti-PD-1 group survived for 60 days. In conclusion, this study develops a sonosensitizer with promising potential for utilizing both MRI-guided SDT and CDT strategies.


Asunto(s)
Neoplasias del Colon , Estructuras Metalorgánicas , Neoplasias , Porfirinas , Terapia por Ultrasonido , Animales , Ratones , Especies Reactivas de Oxígeno , Imagen por Resonancia Magnética , Neoplasias del Colon/diagnóstico por imagen , Neoplasias del Colon/tratamiento farmacológico , Porfirinas/farmacología , Porfirinas/uso terapéutico , Iones , Línea Celular Tumoral
9.
Small ; : e2400668, 2024 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-38881363

RESUMEN

Alkali-metal doped perovskite oxides have emerged as promising materials due to their unique properties and broad applications in various fields, including photovoltaics and catalysis. Understanding the complex interplay between alkali metal doping, structural modifications, and their impact on performance remains a crucial challenge. In this study, this challenge is addressed by investigating the synthesis and properties of Rb-doped perovskite oxides. These results reveal that the doping of Rb into perovskite oxides function as a structural modifier in the as-synthesized samples and during the oxygen evolution reaction (OER) as well. Electron microscopy and first-principles calculations confirm the enrichment of Rb on the surface of the as-synthesized sample. Further investigations into the electrocatalytic reaction revealed that the Rb-doped perovskite underwent drastic restructuring with Rb leaching and formation of strontium oxide.

10.
Small ; : e2402217, 2024 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-38924273

RESUMEN

As demand for higher integration density and smaller devices grows, silicon-based complementary metal-oxide-semiconductor (CMOS) devices will soon reach their ultimate limits. 2D transition metal dichalcogenides (TMDs) semiconductors, known for excellent electrical performance and stable atomic structure, are seen as promising materials for future integrated circuits. However, controlled and reliable doping of 2D TMDs, a key step for creating homogeneous CMOS logic components, remains a challenge. In this study, a continuous electrical polarity modulation of monolayer WS2 from intrinsic n-type to ambipolar, then to p-type, and ultimately to a quasi-metallic state is achieved simply by introducing controllable amounts of vanadium (V) atoms into the WS2 lattice as p-type dopants during chemical vapor deposition (CVD). The achievement of purely p-type field-effect transistors (FETs) is particularly noteworthy based on the 4.7 at% V-doped monolayer WS2, demonstrating a remarkable on/off current ratio of 105. Expanding on this triumph, the first initial prototype of ultrathin homogeneous CMOS inverters based on monolayer WS2 is being constructed. These outcomes validate the feasibility of constructing homogeneous CMOS devices through the atomic doping process of 2D materials, marking a significant milestone for the future development of integrated circuits.

11.
Plant Cell Environ ; 2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38924477

RESUMEN

Predicting soil water status remotely is appealing due to its low cost and large-scale application. During drought, plants can disconnect from the soil, causing disequilibrium between soil and plant water potentials at pre-dawn. The impact of this disequilibrium on plant drought response and recovery is not well understood, potentially complicating soil water status predictions from plant spectral reflectance. This study aimed to quantify drought-induced disequilibrium, evaluate plant responses and recovery, and determine the potential for predicting soil water status from plant spectral reflectance. Two species were tested: sweet corn (Zea mays), which disconnected from the soil during intense drought, and peanut (Arachis hypogaea), which did not. Sweet corn's hydraulic disconnection led to an extended 'hydrated' phase, but its recovery was slower than peanut's, which remained connected to the soil even at lower water potentials (-5 MPa). Leaf hyperspectral reflectance successfully predicted the soil water status of peanut consistently, but only until disequilibrium occurred in sweet corn. Our results reveal different hydraulic strategies for plants coping with extreme drought and provide the first example of using spectral reflectance to quantify rhizosphere water status, emphasizing the need for species-specific considerations in soil water status predictions from canopy reflectance.

12.
Cardiovasc Diabetol ; 23(1): 73, 2024 02 16.
Artículo en Inglés | MEDLINE | ID: mdl-38365751

RESUMEN

BACKGROUND: Stress hyperglycemia ratio (SHR) has recently been recognized as a novel biomarker that accurately reflects acute hyperglycemia status and is associated with poor prognosis of heart failure. We evaluated the relationship between SHR and clinical outcomes in patients with severe aortic stenosis receiving transcatheter aortic valve replacement (TAVR). METHODS: There were 582 patients with severe native aortic stenosis who underwent TAVR consecutively enrolled in the study. The formula used to determine SHR was as follows: admission blood glucose (mmol/L)/(1.59×HbA1c[%]-2.59). The primary endpoint was defined as all-cause mortality, while secondary endpoints included a composite of cardiovascular mortality or readmission for heart failure, and major adverse cardiovascular events (MACE) including cardiovascular mortality, non-fatal myocardial infarction, and non-fatal stroke. Multivariable Cox regression and restricted cubic spline analysis were employed to assess the relationship between SHR and endpoints, with hazard ratios (HRs) and 95% confidence intervals (CIs). RESULTS: During a median follow-up of 3.9 years, a total of 130 cases (22.3%) of all-cause mortality were recorded. Results from the restricted cubic spline analysis indicated a linear association between SHR and all endpoints (p for non-linearity > 0.05), even after adjustment for other confounding factors. Per 0.1 unit increase in SHR was associated with a 12% (adjusted HR: 1.12, 95% CI: 1.04-1.21) higher incidence of the primary endpoint, a 12% (adjusted HR: 1.12, 95% CI: 1.02-1.22) higher incidence of cardiovascular mortality or readmission for heart failure, and a 12% (adjusted HR: 1.12, 95% CI: 1.01-1.23) higher incidence of MACE. Subgroup analysis revealed that SHR had a significant interaction with diabetes mellitus with regard to the risk of all-cause mortality (p for interaction: 0.042). Kaplan-Meier survival analysis showed that there were significant differences in the incidence of all endpoints between the two groups with 0.944 as the optimal binary cutoff point of SHR (all log-rank test: p < 0.05). CONCLUSIONS: Our study indicates linear relationships of SHR with the risk of all-cause mortality, cardiovascular mortality or readmission for heart failure, and MACE in patients with severe aortic stenosis receiving TAVR after a median follow-up of 3.9 years. Patients with an SHR exceeding 0.944 had a poorer prognosis compared to those with lower SHR values.


Asunto(s)
Estenosis de la Válvula Aórtica , Insuficiencia Cardíaca , Hiperglucemia , Reemplazo de la Válvula Aórtica Transcatéter , Humanos , Reemplazo de la Válvula Aórtica Transcatéter/efectos adversos , Pronóstico , Válvula Aórtica/cirugía , Estenosis de la Válvula Aórtica/diagnóstico por imagen , Estenosis de la Válvula Aórtica/cirugía , Estudios Prospectivos , Resultado del Tratamiento , Hiperglucemia/diagnóstico , Factores de Riesgo
13.
Opt Lett ; 49(10): 2837-2840, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38748174

RESUMEN

Microring cavities based on whispering-gallery modes (WGMs) have a very high-quality factor (Q) and a small mode volume, greatly improving the interaction between light and matter, which has attracted great attention in microlaser, nonlinear, and sensing fields. Plasmonics in the microcavity further enhance compression of the optical field. Recently, research on enhanced optical sensing sensitivity and low threshold laser based on exceptional points (EPs) is quite impressive. In this work, we propose a new, to our knowledge, all-optical switch by using the bistable effect under the EP of an ultra-compact plasmonic racetrack resonator and perform numerical simulations using the finite-difference time-domain (FDTD) method. The introduction of EPs further enhances the localization of the light field and thus improves the Kerr nonlinear effect of the microcavity; low threshold optical bistability is achieved. The results show that the device under an EP has a relatively lower threshold (input optical power threshold of 2.2 MW/cm2), shorter switching time (1.725 ps), and significantly improved switching contrast (17.16 dB) compared with those without EP. Our research lays the groundwork for optical switches that are chip-integrated, have low power consumption, and exhibit short switching times.

14.
Respir Res ; 25(1): 144, 2024 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-38553718

RESUMEN

BACKGROUND: The aim of this study was to develop a nomogram by combining chest computed tomography (CT) images and clinicopathological predictors to assess the survival outcomes of patients with primary pulmonary lymphoepithelial carcinoma (PLEC). METHODS: 113 patients with stage I-IV primary PLEC who underwent treatment were retrospectively reviewed. The Cox regression analysis was performed to determine the independent prognostic factors associated with patient's disease-free survival (DFS) and cancer-specific survival (CSS). Based on results from multivariate Cox regression analysis, the nomograms were constructed with pre-treatment CT features and clinicopathological information, which were then assessed with respect to calibration, discrimination and clinical usefulness. RESULTS: Multivariate Cox regression analysis revealed the independent prognostic factors for DFS were surgery resection and hilar and/or mediastinal lymphadenopathy, and that for CSS were age, smoking status, surgery resection, tumor site in lobe and necrosis. The concordance index (C­index) of nomogram for DFS and CSS were 0.777 (95% CI: 0.703-0.851) and 0.904 (95% CI: 0.847-0.961), respectively. The results of the time­dependent C­index were internally validated using a bootstrap resampling method for DFS and CSS also showed that the nomograms had a better discriminative ability. CONCLUSIONS: We developed nomograms based on clinicopathological and CT factors showing a good performance in predicting individual DFS and CSS probability among primary PLEC patients. This prognostic tool may be valuable for clinicians to more accurately drive treatment decisions and individualized survival assessment.


Asunto(s)
Carcinoma , Nomogramas , Humanos , Estudios Retrospectivos , Tomografía Computarizada por Rayos X , Supervivencia sin Enfermedad , Pronóstico
15.
Artículo en Inglés | MEDLINE | ID: mdl-38591772

RESUMEN

Two yeast strains, designated as 19-39-3 and 19-40-2, obtained from the fruiting bodies of Trametes versicolor and Marasmius siccus collected in Yunwu Mountain Forest Park, PR China, have been identified as representing a novel asexual ascomycetous yeast species. From the results of phylogenetic analyses of the sequences of the D1/D2 domains of the large subunit (LSU) rRNA, small subunit (SSU) rRNA and translation elongation factor 1-α (TEF1) genes, it was determined that these strains represent a member of the genus Wickerhamomyces, with Wickerhamomyces alni and Candida ulmi as the closest relatives. The novel species exhibited 6.6 and 6.7% differences in the D1/D2 domains compared with W. alni and C. ulmi, respectively. Additionally, distinct biochemical and physiological differences were observed between the novel species and its related counterparts. No sexual reproduction was observed in these strains, leading to the proposal of the name Wickerhamomyces corioli f.a., sp. nov. for this newly discovered species.


Asunto(s)
Agaricales , Saccharomycetales , Filogenia , ADN Espaciador Ribosómico/genética , Agaricales/genética , Trametes/genética , Análisis de Secuencia de ADN , Composición de Base , ARN Ribosómico 16S/genética , ADN Bacteriano/genética , Técnicas de Tipificación Bacteriana , Ácidos Grasos/química , Saccharomycetales/genética , ADN de Hongos/genética , Técnicas de Tipificación Micológica
16.
Analyst ; 149(12): 3444-3455, 2024 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-38738630

RESUMEN

Numerous studies have revealed a close correlation between the levels of apolipoproteins (Apos) (including lipoprotein(a) [Lp(a)]) and an increased risk of cardiovascular disease in recent decades. However, clinically, lipid profiling remains limited to the conventional plasma levels of cholesterol, triglyceride, ApoA1, and ApoB, which brings the necessity to quantify more apolipoproteins in human plasma. In this study, we simultaneously quantified 13 apolipoproteins and Lp(a) in 5 µL of human plasma using the LC-MS/MS platform. A method was developed for the precise detection of Lp(a), ApoA1, A2, A5, B, C1, C2, C3, D, E, H, L1, M, and J. Suitable peptides were selected and optimized to achieve clear separation of each peak. Method validation consisting of linearity, sensitivity, accuracy and precision, recovery, and matrix effects was evaluated. The intra-day CV ranged from 0.58% to 14.2% and the inter-day CV ranged from 0.51% to 13.3%. The recovery rates ranged from 89.8% to 113.7%, while matrix effects ranged from 85.4% to 113.9% for all apolipoproteins and Lp(a). Stability tests demonstrated that these apolipoproteins remained stable for 3 days at 4 °C and 7 days at -20 °C. This validated method was successfully applied to human plasma samples obtained from 45 volunteers. The quantitative results of ApoA1, ApoB, and Lp(a) exhibited a close correlation with the results from the immunity transmission turbidity assay. Collectively, we developed a robust assay that can be used for high-throughput quantification of apolipoproteins and Lp(a) simultaneously for investigating related risk factors in patients with dyslipidemia.


Asunto(s)
Apolipoproteínas , Lipoproteína(a) , Espectrometría de Masas en Tándem , Humanos , Espectrometría de Masas en Tándem/métodos , Apolipoproteínas/sangre , Lipoproteína(a)/sangre , Cromatografía Liquida/métodos , Análisis Químico de la Sangre/métodos , Cromatografía Líquida con Espectrometría de Masas
17.
Inorg Chem ; 63(27): 12426-12432, 2024 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-38905706

RESUMEN

This report describes the synthesis and characterization of two heterobimetallic Li-Zn coordination isomers [Li2Zn2(tbaoac)6] (tbaoac = tert-butyl acetoacetato) that have been isolated separately by the same stoichiometric reaction run in different organic solvents. The 6-coordinated zinc isomer (6-Zn) was synthesized in acetone with high yield, while the 5-coordinated one (5-Zn) was readily obtained from ethanol. The 5-Zn isomer has a low solubility in organic solvents such as alkanes and haloalkanes, while its 6-Zn counterpart exhibits a good solubility in almost all common solvents. Two isomeric molecules feature similar centrosymmetric tetranuclear cyclic assemblies, which are different in their arrangement of tbaoac ligands. While all ligands act as µ2-type in the structure of 5-Zn, the two tbaoac groups chelating Li appear as µ3-type in 6-Zn, thus providing an additional coordination for Zn ions. However, the real structural transformation between these isomers was shown to be more complex than simply making or breaking a couple of Zn-O bonds. X-ray single-crystal structure analysis, powder X-ray diffraction, multinuclear NMR, DART mass spectrometry, ICP-OES analysis, and TGA have been employed for the characterization of the isomers. The combination of powder X-ray diffraction and 1H NMR investigation revealed that 6-Zn isomer can be quantitatively transformed to 5-Zn in ethanol, while the reverse conversion instantly takes place in acetone.

18.
Inorg Chem ; 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38950312

RESUMEN

Cobalt (Co)-based materials have been widely investigated as hopeful noble-metal-free alternatives for the oxygen evolution reaction (OER) in alkaline electrolytes, which is crucial for generating hydrogen by water electrolysis. Herein, cobalt-based telluride particles with good electronic conductivity as anodic electrocatalysts were prepared under vacuum by the solid-state strategy, which display remarkable activities toward the OER. Nickel (Ni) and iron (Fe) codoped cobalt telluride (NiFe-CoTe) exhibits an overpotential of 321 mV to achieve a current density of 10 mA cm-2 and a Tafel slope of 51.8 mV dec-1, outperforming the performances of CoTe, CoTe2, and IrO2. According to the DFT calculation, the adsorbed hydroxyl-assisted adsorbate evolution mechanism was proposed for the OER process of NiFe-CoTe, which reveals the synergetic effect toward OER induced by codoping of the Ni and Fe atoms. This work proposes a rational strategy to prepare cobalt-based tellurides as efficient OER catalysts in alkaline electrolytes, providing a new strategy to prepare and regulate metal-based tellurides for catalysis and beyond.

19.
Fish Shellfish Immunol ; 149: 109606, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38705547

RESUMEN

Moritella viscosa (M. viscosa) and sea lice (Lepeophtheirus salmonis) are severe pathogens that primarily infect the skin of Atlantic salmon (Salmo salar), which cause significant economic losses in the farming industry. However, the pathogenesis and molecular mechanisms underlying the host's immune defence at the post-transcriptional level remain unclear. Alternative splicing (AS) is an evolutionarily conserved post-transcriptional mechanism that can greatly increase the richness of the transcriptome and proteome. In this study, transcriptomic data derived from skin tissues of Atlantic salmon after M. viscosa and sea lice infections were used to examine the AS profiles and their differential expression patterns. In total, we identified 33,044 AS events (involving 13,718 genes) in the control (CON) group, 35,147 AS events (involving 14,340 genes) in the M. viscosa infection (MV) group, and 30,364 AS events (involving 13,142 genes) in the sea lice infection (LC) group, respectively. Among the five types of AS identified in our study (i.e., SE, A5SS, A3SS, MXE, and RI), SE was the most prevalent type in all three groups (i.e., CON, MV, and LC groups). Decreased percent-spliced-in (PSI) levels were observed in SE events under both MV- and LC-infected conditions, suggesting that MV or LC infection elevated exon-skipping isoforms and promoted the selection of shorter transcripts in numerous DAS genes. In addition, most of the differential AS genes were found to be associated with pathways related to mRNA regulation, epithelial or muscle development, and immune response. These findings provide novel insights into the role of AS in host-pathogen interactions and represent the first comparative analysis of AS in response to bacterial and parasitic infections in fish.


Asunto(s)
Empalme Alternativo , Copépodos , Enfermedades de los Peces , Moritella , Salmo salar , Animales , Salmo salar/inmunología , Salmo salar/genética , Copépodos/fisiología , Enfermedades de los Peces/inmunología , Moritella/inmunología , Moritella/genética , Transcriptoma , Infestaciones Ectoparasitarias/veterinaria , Infestaciones Ectoparasitarias/inmunología , Infestaciones Ectoparasitarias/genética
20.
Org Biomol Chem ; 22(3): 486-490, 2024 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-38111368

RESUMEN

In contrast to the previously reported intramolecular aryl migration, we present the selective sulfenylation of ortho-trifluoromethanesulfonate (OTf) substituted diaryliodonium salts with thiols. As such, diarylsulfides bearing vicinal OTf groups were synthesized in good yields. The unique reactivity of the vicinal OTf group and the sulfur atom in arylsulfides offers further transformations.

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