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1.
Biomaterials ; 313: 122776, 2025 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-39236629

RESUMEN

Surgical resection, the mainstay for melanoma treatment, faces challenges due to high tumor recurrence rates and complex postoperative wound healing. Chronic inflammation from residual disease and the risk of secondary infections impede healing. We introduce an innovative, injectable hydrogel system that integrates a multifaceted therapeutic approach. The hydrogel, crosslinked by calcium ions with sodium alginate, encapsulates a blood clot rich in dendritic cells (DCs) chemoattractants and melanoma cell-derived nanovesicles (NVs), functioning as a potent immunostimulant. This in situ recruitment strategy overcomes the limitations of subcutaneous tumor vaccine injections and more effectively achieves antitumor immunity. Additionally, the hydrogel incorporates Chlorella extracts, enhancing its antimicrobial properties to prevent wound infections and promote healing. One of the key findings of our research is the dual functionality of Chlorella extracts; they not only expedite the healing process of infected wounds but also increase the hydrogel's ability to stimulate an antitumor immune response. Given the patient-specific nature of the blood clot and NVs, our hydrogel system offers customizable solutions for individual postoperative requirements. This personalized approach is highlighted by our study, which demonstrates the synergistic impact of the composite hydrogel on preventing melanoma recurrence and hastening wound healing, potentially transforming postsurgical melanoma management.


Asunto(s)
Células Dendríticas , Hidrogeles , Melanoma , Cicatrización de Heridas , Hidrogeles/química , Animales , Células Dendríticas/inmunología , Células Dendríticas/efectos de los fármacos , Melanoma/terapia , Melanoma/patología , Cicatrización de Heridas/efectos de los fármacos , Humanos , Recurrencia Local de Neoplasia/prevención & control , Ratones Endogámicos C57BL , Antiinfecciosos/uso terapéutico , Antiinfecciosos/farmacología , Ratones , Línea Celular Tumoral , Femenino
2.
Org Lett ; 2024 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-39365645

RESUMEN

A DMSO-catalyzed double P-O bond or double P-S bond formation of phosphinic acid with an O- or S-containing nucleophile has been developed. Under metal-free and mild conditions, this simple procedure provides a compatible and rapid access to a variety of phosphonates and dithiophosphates. The DFT calculation of stabilization energy (SE) and the mechanism studies demonstrated that the "just right" Lewis base property and the relatively "soft" interaction strength with the phosphenium-dication ensure the unique catalytic activity of DMSO in this transformation.

3.
Clin Appl Thromb Hemost ; 30: 10760296241282771, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39233654

RESUMEN

PURPOSE: To investigate the differences in survival after venous thromboembolism (VTE) and anticoagulation efficacy and safety between catheter (CRVTE) and non-catheter-related VTE (NCRVTE) in cancer patients. METHODS: A retrospective research was conducted, and consecutive cancer (digestive, respiratory, genitourinary, blood and lymphatic, and the other cancers) patients with VTE were enrolled. The anticoagulation therapies included low-molecular-weight heparin (LMWH), warfarin, new type of direct oral anticoagulants (NDOACs), LMWH combined with warfarin, and LMWH combined with NDOACs. Data were collected from the electronic medical record database of our hospital and were analyzed accordingly by Kruskal-Wallis H Test, Chi-square test, Fisher's exact test, Logistic regressions, Kaplan-Meier analysis, and Cox regressions. RESULTS: 263 patients were included, median age in years (interquartile range) was 64(56-71) and 60.5% were male. VTE recurrence rate was 16.7% in CRVTE group which was significantly lower than 34.8% in NCRVTE group (P = .032). Heart diseases were independently associated with VTE recurrence (P = .025). Kaplan-Meier survival estimates at 1, 2, and 3 years for CRVTE group were 62.5%, 60.0%, and 47.5%, respectively, compared with 47.9% (P = .130), 38.7% (P = .028), and 30.1% (P = .046), respectively, for NCRVTE group. Cox regression showed surgery (P = .003), anticoagulation therapy types (P = .009), VTE types (P = .006) and cancer types (P = .039) were independent prognostic factors for 3-year survival after VTE. Nonmajor and major bleeding were not significantly different (P = .417). Anticoagulation therapy types were independently associated with the bleeding events (P = .030). CONCLUSIONS: Cancer patients with CRVTE potentially have a better anticoagulation efficacy and survival compared to NCRVTE, and the anticoagulation safety seems no significant difference.


Asunto(s)
Anticoagulantes , Neoplasias , Tromboembolia Venosa , Humanos , Tromboembolia Venosa/tratamiento farmacológico , Tromboembolia Venosa/etiología , Tromboembolia Venosa/mortalidad , Neoplasias/complicaciones , Neoplasias/mortalidad , Neoplasias/tratamiento farmacológico , Masculino , Femenino , Anticoagulantes/uso terapéutico , Anticoagulantes/efectos adversos , Persona de Mediana Edad , Anciano , Estudios Retrospectivos , Tasa de Supervivencia
4.
Internet Interv ; 38: 100767, 2024 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-39258012

RESUMEN

With the increasing aging population, contemporary society faces the imperative to develop approaches that efficiently delay the age-related decline in working memory capacity, which is a critical area within cognitive aging research. Nevertheless, there is insufficient evidence to support the efficacy of verbal working memory training across various sensory modalities (visual, auditory, and audiovisual) in enhancing the verbal working memory capacity of older adults. In this study, 60 healthy older adults (mean age = 67.07 ± 3.79 years, comprising 34 women and 26 men, mean education = 15.55 ± 2.53 years) were randomly assigned to one of four groups: visual verbal working memory (V-VWM) group, auditory verbal working memory (A-VWM) group, visual-auditory verbal working memory (VA-VWM) group, and a control group. The training duration spanned 12 days. We also investigated whether baseline level and education predicted the outcomes. Findings indicated that V-VWM training had a large effect on improving V-VWM task performance (Cohen's d = 1.765), A-VWM training showed a substantial effect on A-VWM task performance (Cohen's d = 1.904), and VA-VWM training demonstrated a significant effect on VA-VWM task performance (Cohen's d = 2.319) over pretest scores in older adults. Enhancements achieved through V-VWM training exhibited near transfer effects, improving performance in both A-VWM and VA-VWM tasks. In contrast, gains from A-VWM training were selectively transferred to the VA-VWM task. Furthermore, VA-VWM training led to improvements not only in V-VWM and A-VWM tasks but also extended to verbal operation span task with a significant 29.7 % increase. However, no significant transfer effects were observed for the DSF and DSB tasks across the three training groups. The maintenance effect of VA-VWM training persisted for two weeks across tasks involving VA-VWM, V-VWM, and A-VWM. The baseline of VWM span score influence the effect of V-VWM training and transfer effect of VA-VWM training. Education level did not predict the training effects of V-VWM, A-VWM, and VA-VWM. These findings highlight the nuanced effects of sensory-specific verbal working memory training in older adults, emphasizing the potential of tailored interventions to enhance specific aspects of cognitive function, while also highlighting the promising applications of mobile device training in enhancing cognitive skills among the elderly.

5.
Proc Natl Acad Sci U S A ; 121(37): e2408716121, 2024 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-39226360

RESUMEN

Bacterial evolution, particularly in hospital settings, is leading to an increase in multidrug resistance. Understanding the basis for this resistance is critical as it can drive discovery of new antibiotics while allowing the clinical use of known antibiotics to be optimized. Here, we report a photoactive chemical probe for superresolution microscopy that allows for the in situ probing of antibiotic-induced structural disruption of bacteria. Conjugation between a spiropyran (SP) and galactose via click chemistry produces an amphiphilic photochromic glycoprobe, which self-assembles into glycomicelles in water. The hydrophobic inner core of the glycomicelles allows encapsulation of antibiotics. Photoirradiation then serves to convert the SP to the corresponding merocyanine (MR) form. This results in micellar disassembly allowing for release of the antibiotic in an on-demand fashion. The glycomicelles of this study adhere selectively to the surface of a Gram-negative bacterium through multivalent sugar-lectin interaction. Antibiotic release from the glycomicelles then induces membrane collapse. This dynamic process can be imaged in situ by superresolution spectroscopy owing to the "fluorescence blinking" of the SP/MR photochromic pair. This research provides a high-precision imaging tool that may be used to visualize how antibiotics disrupt the structural integrity of bacteria in real time.


Asunto(s)
Antibacterianos , Benzopiranos , Indoles , Antibacterianos/farmacología , Antibacterianos/química , Benzopiranos/química , Benzopiranos/farmacología , Indoles/química , Micelas , Nitrocompuestos/química , Pirimidinonas/química , Pirimidinonas/farmacología
6.
Nat Commun ; 15(1): 7751, 2024 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-39237540

RESUMEN

While rapid demographic changes in Asia are driving the incidence of chronic aging-related diseases, the limited availability of high-quality in vivo data hampers our ability to understand complex multi-factorial contributions, including gut microbial, to healthy aging. Leveraging a well-phenotyped cohort of community-living octogenarians in Singapore, we used deep shotgun-metagenomic sequencing for high-resolution taxonomic and functional characterization of their gut microbiomes (n = 234). Joint species-level analysis with other Asian cohorts identified distinct age-associated shifts characterized by reduction in microbial richness, and specific Alistipes and Bacteroides species enrichment (e.g., Alistipes shahii and Bacteroides xylanisolvens). Functional analysis confirmed these changes correspond to metabolic potential expansion in aging towards alternate pathways synthesizing and utilizing amino-acid precursors, vis-à-vis dominant microbial guilds producing butyrate in gut from pyruvate (e.g., Faecalibacterium prausnitzii, Roseburia inulinivorans). Extending these observations to key clinical markers helped identify >10 robust microbial associations to inflammation, cardiometabolic and liver health, including potential probiotic species (e.g., Parabacteroides goldsteinii) and pathobionts (e.g., Klebsiella pneumoniae), highlighting the microbiome's role as biomarkers and potential targets for promoting healthy aging.


Asunto(s)
Envejecimiento , Microbioma Gastrointestinal , Metagenoma , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Pueblo Asiatico/genética , Bacterias/genética , Bacterias/clasificación , Bacterias/metabolismo , Bacterias/aislamiento & purificación , Bacteroides/genética , Bacteroides/metabolismo , Estudios de Cohortes , Heces/microbiología , Microbioma Gastrointestinal/genética , Metagenómica/métodos , Fenotipo , Singapur , Octogenarios
7.
Phytochemistry ; 229: 114267, 2024 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-39216632

RESUMEN

In order to elucidate the mass fragmentation patterns and unveil more undescribed ophiobolin analogs, the mass fragmentation patterns of ophiobolins were analyzed based on UPLC-Q-TOF-MS/MS experiments. Different kinds of rearrangements (including McLafferty rearrangement) were the main cleavage patterns. Twenty-six (9-31) analogs were then tentatively characterized based on their mass analysis, and three undescribed ophiobolins (6-8) and a known analogue (5) were isolated in target. Compound 5 possesses a rare polycyclic carbon skeleton only recently reported, and compound 6 contains an undescribed lactone ring system fused with A/B ring at C-3/C-21, whereas compounds 7 and 8 have a peroxyl group in the side chain, which is the first reported in all ophiobolins. Compounds 5 and 7 displayed significant cytotoxicity against MCF-7 cancer cells.

8.
Biomedicines ; 12(8)2024 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-39200375

RESUMEN

Postural Orthostatic Tachycardia Syndrome (POTS) affects up to 1% of the US population, predominantly women, and is characterized by a complex, elusive etiology and heterogeneous phenotypes. This review delves into the intricate physiology and etiology of POTS, decoding the roles of the sinoatrial node, the autonomic nervous system, fluid dynamics, and the interplay between the immune and endocrine systems. It further examines key contributing factors such as dysautonomia, thoracic hypovolemia, autonomic neuropathies, sympathetic denervation, autoimmune responses, and associations with conditions such as small-fiber neuropathy and mast cell activation syndrome. Given the numerous mysteries surrounding POTS, we also cautiously bring attention to sinoatrial node and myocardial function, particularly in how the heart responds to stress despite exhibiting a normal cardiac phenotype at rest. The potential of genomic research in elucidating the underlying mechanisms of POTS is emphasized, suggesting this as a valuable approach that is likely to improve our understanding of the genetic underpinnings of POTS. The review introduces a tentative classification system for the etiological factors in POTS, which seeks to capture the condition's diverse aspects by categorizing various etiological factors and acknowledging co-occurring conditions. This classification, while aiming to enhance understanding and optimize treatment targets, is presented as a preliminary model needing further study and refinement. This review underscores the ongoing need for research to unravel the complexities of POTS and to develop targeted therapies that can improve patient outcomes.

9.
J Am Chem Soc ; 146(35): 24503-24514, 2024 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-39172733

RESUMEN

A facile approach to obtaining densely functionalized cyclopropanes is described. The reaction proceeds under mild conditions via the directed nucleopalladation of nonconjugated alkenes with readily available pronucleophiles and gives excellent yields and good anti-selectivity using I2 and TBHP as oxidants. Pronucleophiles bearing a diverse collection of electron-withdrawing groups, including -CN, -CO2R, -COR, -SO2Ph, -CONHR, and -NO2, are well tolerated. Internal alkenes, which are generally challenging substrates in other cyclopropanation methods, provide excellent yields and good diastereoselectivity in this methodology, allowing for controlled access to cyclopropanes substituted at all three C atoms. DFT calculations and mechanistic experiments reveal that the major mechanistic pathway involves the initial α-iodination of the nucleophile, followed by anti-carbopalladation and intramolecular C(sp3)-I oxidative addition. Strain-release-promoted C(sp3)-C(sp3) reductive elimination then furnishes the cyclopropanated product.

11.
Mol Oncol ; 2024 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-39140252

RESUMEN

There are two key signatures of pediatric cancers: (a) higher prevalence of germline alterations and (b) heterogeneity in alteration types. Recent population-based assessments have demonstrated that children with birth defects (BDs) are more likely to develop cancer even without chromosomal anomalies; therefore, explorations of genetic alterations in children with BDs and cancers could provide new insights into the underlying mechanisms for pediatric tumor development. We performed whole-genome sequencing (WGS) on blood-derived DNA for 1556 individuals without chromosomal anomalies, including 454 BD probands with at least one type of malignant tumor, 757 cancer-free children with BDs, and 345 healthy individuals, focusing on copy number variation (CNV) analysis. Roughly half of the children with BD-cancer have CNVs that are not identified in BD-only/healthy individuals, and CNVs are not evenly distributed among these patients. Strong heterogeneity was observed, with a limited number of cancer predisposition genes containing CNVs in more than three patients. Moreover, functional enrichments of genes with CNVs showed that dozens of patients have variations related to the same biological pathways, such as deletions of genes with neurological functions and duplications of immune response genes. Phenotype clustering uncovered recurrences of patients with sarcoma: A notable enrichment was observed involving non-coding RNA regulators, showing strong signals related to growth and cancer regulations in functional analysis. In conclusion, we conducted one of the first genomic studies exploring the impact of CNVs on cancer development in children with BDs, unveiling new insights into the underlying biological processes.

12.
Acta Pharmacol Sin ; 2024 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-39160244

RESUMEN

Pulmonary fibrosis (PF) is a chronic, progressive and irreversible interstitial lung disease characterized by unremitting pulmonary myofibroblasts activation, extracellular matrix (ECM) deposition and inflammatory recruitment. PF has no curable medication yet. In this study we investigated the molecular pathogenesis and potential therapeutic targets of PF and discovered drug lead compounds for PF therapy. A murine PF model was established in mice by intratracheal instillation of bleomycin (BLM, 5 mg/kg). We showed that the protein level of pulmonary protein phosphatase magnesium-dependent 1A (PPM1A, also known as PP2Cα) was significantly downregulated in PF patients and BLM-induced PF mice. We demonstrated that TRIM47 promoted ubiquitination and decreased PPM1A protein in PF progression. By screening the lab in-house compound library, we discovered otilonium bromide (OB, clinically used for treating irritable bowel syndrome) as a PPM1A enzymatic activator with an EC50 value of 4.23 µM. Treatment with OB (2.5, 5 mg·kg-1·d-1, i.p., for 20 days) significantly ameliorated PF-like pathology in mice. We constructed PF mice with PPM1A-specific knockdown in the lung tissues, and determined that by targeting PPM1A, OB treatment suppressed ECM deposition through TGF-ß/SMAD3 pathway in fibroblasts, repressed inflammatory responses through NF-κB/NLRP3 pathway in alveolar epithelial cells, and blunted the crosstalk between inflammation in alveolar epithelial cells and ECM deposition in fibroblasts. Together, our results demonstrate that pulmonary PPM1A activation is a promising therapeutic strategy for PF and highlighted the potential of OB in the treatment of the disease.

13.
ACS Omega ; 9(27): 29379-29390, 2024 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-39005832

RESUMEN

Herein, we explored the oxidative coupling reactions of carbazole-based polycyclic aromatic hydrocarbons using traditional Scholl reactions and electrochemical oxidation. Our findings indicate that the oxidation predominantly occurs at the carbazole functional group. The underlying reaction mechanisms were also clarified through theoretical investigations, highlighting that the primary oxidation pathway involves the 3,6-positions of the carbazole moiety, which is attributable to its high electron density.

14.
Artículo en Inglés | MEDLINE | ID: mdl-38956918

RESUMEN

Diabetes mellitus is a common chronic metabolic disease characterized by a high incidence and disability rate. Intestinal flora refers to the microbial community that lives in the intestines and plays a crucial role in maintaining intestinal health and the human immune system. In recent years, an increasing body of research has revealed a close relationship between intestinal flora and diabetes. The pathophysiological mechanisms between them have also been constantly uncovered, and the regulation of intestinal flora has shown promising efficacy in the adjuvant treatment of diabetes. This study mainly summarized the characteristics and mechanisms of intestinal flora in patients with diabetes in recent years, as well as the methods of regulating intestinal flora to prevent and treat diabetes, and prospected the future research direction. This will offer a theoretical basis for the clinical adjuvant treatment of diabetes with intestinal flora and the development of new drugs.

15.
Biosens Bioelectron ; 263: 116580, 2024 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-39033653

RESUMEN

A Mn-based nanozyme, Mn-uNF/Si, with excellent alkali phosphatase-like activity was designed by in-situ growth of ultrathin Mn-MOF on the surface of silicon spheres, and implemented as an effective solid Lewis-Brønsted acid catalyst for broad-spectrum dephosphorylation. H218O-mediated GC-MS studies confirmed the cleavage sites and the involvement of H2O in the new bonds. DRIFT NH3-IR and in-situ ATR-FTIR confirmed the coexistence of Lewis-Brønsted acid sites and the adjustment of adsorption configurations at the interfacial sites. In addition, a green transformation route of "turning waste into treasure" was proposed for the first time ("OPs→PO43-→P food additive") using edible C. reinhardtii as a transfer station. By alkali etching of Mn-uNF/Si, a nanozyme Mn-uNF with laccase-like activity was obtained. Intriguingly, glyphosate exhibits a laccase-like fingerprint-like response (+,-) of Mn-uNF, and a non-enzyme amplified sensor was thus designed, which shows a good linear relationship with Glyp in a wide range of 0.49-750 µM, with a low LOD of 0.61 µM, as well as high selectivity and anti-interference ability under the co-application of phosphate fertilizers and multiple pesticides. This work provides a controllable methodology for the design of bifunctional nanozymes, which sheds light on the highly efficient green transformation of OPs, and paves the way for the selective recognition and quantification of glyphosate. Mechanistically, we also provided deeper insights into the structure-activity relationship at the atomic scale.


Asunto(s)
Técnicas Biosensibles , Glicina , Glifosato , Manganeso , Glicina/análogos & derivados , Glicina/química , Manganeso/química , Técnicas Biosensibles/métodos , Compuestos Organofosforados/química , Compuestos Organofosforados/análisis , Estructuras Metalorgánicas/química , Herbicidas/química , Herbicidas/análisis , Nanoestructuras/química , Tecnología Química Verde/métodos , Silicio/química , Catálisis
16.
J Nat Prod ; 87(6): 1660-1665, 2024 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-38888514

RESUMEN

Chetocochliodin M (5) containing a rare cage-ring and chetocochliodin N (6) featuring an unusual piperazine-2,3-dione ring system together with known analogues chetomin (1), chetoseminudin C (2), chetocochliodin I (3), and oidioperazine E (4) were targeted for purification from the fungus Chaetomium cochliodes using a UPLC-Q-TOF-MS/MS approach. The structures of the new compounds were elucidated using HR-ESI-MS, NMR, and ECD spectra. Compounds 1, 3, and 6 exhibited strong cytotoxic activities against A549 and HeLa cancer cell lines.


Asunto(s)
Chaetomium , Espectrometría de Masas en Tándem , Chaetomium/química , Humanos , Estructura Molecular , Espectrometría de Masas en Tándem/métodos , Células HeLa , Cromatografía Líquida de Alta Presión/métodos , Antineoplásicos/farmacología , Antineoplásicos/química , Antineoplásicos/aislamiento & purificación , Ensayos de Selección de Medicamentos Antitumorales , Células A549 , Piperazinas/farmacología , Piperazinas/química , Piperazinas/aislamiento & purificación
17.
bioRxiv ; 2024 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-38746128

RESUMEN

The advent of long-read single-cell transcriptome sequencing (lr-scRNA-Seq) represents a significant leap forward in single-cell genomics. With the recent introduction of R10 flowcells by Oxford Nanopore, we propose that previous computational methods designed to handle high sequencing error rates are no longer relevant, and that the prevailing approach using short reads to compile "barcode space" (candidate barcode list) to de-multiplex long reads are no longer necessary. Instead, computational methods should now shift focus on harnessing the unique benefits of long reads to analyze transcriptome complexity. In this context, we introduce a comprehensive suite of computational methods named Single-Cell Omics for Transcriptome CHaracterization (SCOTCH). Our method is compatible with the single-cell library preparation platform from both 10X Genomics and Parse Biosciences, facilitating the analysis of special cell populations, such as neurons, hepatocytes and developing cardiomyocytes. We specifically re-formulated the transcript mapping problem with a compatibility matrix and addressed the multiple-mapping issue using probabilistic inference, which allows the discovery of novel isoforms as well as the detection of differential isoform usage between cell populations. We evaluated SCOTCH through analysis of real data across different combinations of single-cell libraries and sequencing technologies (10X + Illumina, Parse + Illumina, 10X + Nanopore_R9, 10X + Nanopore_R10, Parse + Nanopore_R10), and showed its ability to infer novel biological insights on cell type-specific isoform expression. These datasets enhance the availability of publicly available data for continued development of computational approaches. In summary, SCOTCH allows extraction of more biological insights from the new advancements in single-cell library construction and sequencing technologies, facilitating the examination of transcriptome complexity at the single-cell level.

18.
J Cereb Blood Flow Metab ; : 271678X241258576, 2024 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-38820436

RESUMEN

Spontaneous cerebral vasomotion, characterized by ∼0.1 Hz rhythmic contractility, is crucial for brain homeostasis. However, our understanding of vasomotion is limited due to a lack of high-precision analytical methods to determine single vasomotion events at basal levels. Here, we developed a novel strategy that integrates a baseline smoothing algorithm, allowing precise measurements of vasodynamics and concomitant Ca2+ dynamics in mouse cerebral vasculature imaged by two-photon microscopy. We identified several previously unrecognized vasomotion properties under different physiological and pathological conditions, especially in ischemic stroke, which is a highly harmful brain disease that results from vessel occlusion. First, the dynamic characteristics between SMCs Ca2+ and corresponding arteriolar vasomotion are correlated. Second, compared to previous diameter-based estimations, our radius-based measurements reveal anisotropic vascular movements, enabling a more precise determination of the latency between smooth muscle cell (SMC) Ca2+ activity and vasoconstriction. Third, we characterized single vasomotion event kinetics at scales of less than 4 seconds. Finally, following pathological vasoconstrictions induced by ischemic stroke, vasoactive arterioles entered an inert state and persisted despite recanalization. In summary, we developed a highly accurate technique for analyzing spontaneous vasomotion, and our data suggested a potential strategy to reduce stroke damage by promoting vasomotion recovery.

19.
J Org Chem ; 89(10): 6729-6739, 2024 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-38690961

RESUMEN

We have developed a Tf2O-mediated approach for the direct amination of either P(O)-OH or P(O)-H reagents with a variety of aliphatic or aromatic amines. Without the requirement of precious metals and toxic reagents, this protocol provides an alternative route to various phosphinamides and phosphoramides. The reaction proceeds under simple and mild conditions and can be effectively scaled up with similar efficiency.

20.
ACS Appl Mater Interfaces ; 16(22): 29016-29028, 2024 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-38783839

RESUMEN

Graphene has received much scientific attention as an electrode material for lithium-ion batteries because of its extraordinary physical and electrical properties. However, the lack of structural control and restacking issues have hindered its application as carbon-based anode materials for next generation lithium-ion batteries. To improve its performance, several modification approaches such as edge-functionalization and electron-donating/withdrawing substitution have been considered as promising strategies. In addition, group 7A elements have been recognized as critical elements due to their electronegativity and electron-withdrawing character, which are able to further improve the electronic and structural properties of materials. Herein, we elucidated the chemistry of nanographenes with edge-substituted group 7A elements as lithium-ion battery anodes. The halogenated nanographenes were synthesized via bottom-up organic synthesis to ensure the structural control. Our study reveals that the presence of halogens on the edge of nanographenes not only tunes the structural and electronic properties but also impacts the material stability, reactivity, and Li+ storage capability. Further systematic spectroscopic studies indicate that the charge polarization caused by halogen atoms could regulate the Li+ transport, charge transfer energy, and charge storage behavior in nanographenes. Overall, this study provides a new molecular design for nanographene anodes aiming for next-generation lithium-ion batteries.

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