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1.
PLoS Pathog ; 19(5): e1011396, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-37172058

RESUMEN

Infection with the cestode Echinococcus multilocularis (E. multilocularis) causes alveolar echinococcosis (AE), a tumor-like disease predominantly affecting the liver but able to spread to any organ. T cells develop functional defects during chronic E. multilocularis infection, mostly due to upregulation of inhibitory receptors such as T-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domains (TIGIT) and programmed death-1 (PD-1). However, the role of lymphocyte activation gene-3 (LAG3), an inhibitory receptor, in AE infection remains to be determined. Here, we discovered that high expression of LAG3 was mainly found in CD4+ T cells and induced regulatory T cells (iTregs) in close liver tissue (CLT) from AE patients. In a mouse model of E. multilocularis infection, LAG3 expression was predominantly found in T helper 2 (Th2) and Treg subsets, which secreted significantly more IL-4 and IL-10, resulting in host immune tolerance and disease progression at a late stage. Furthermore, LAG3 deficiency was found to drive the development of effector memory CD4+ T cells and enhance the type 1 CD4+ T-cell immune response, thus inhibiting metacestode growth in vivo. In addition, CD4+ T cells from LAG3-deficient mice produced more IFN-γ and less IL-4 when stimulated by E. multilocularis protoscoleces (EmP) antigen in vitro. Finally, adoptive transfer experiments showed that LAG3-knockout (KO) CD4+ T cells were more likely to develop into Th1 cells and less likely to develop into Tregs in recipient mice. Our work reveals that high expression of LAG3 accelerates AE disease progression by modulating the immune imbalance of CD4+ T-cell subsets. These findings may provide a novel immunotherapeutic strategy against E. multilocularis infection.


Asunto(s)
Linfocitos T CD4-Positivos , Interleucina-4 , Ratones , Animales , Regulación hacia Arriba , Células TH1 , Progresión de la Enfermedad
2.
Proc Natl Acad Sci U S A ; 119(22): e2120633119, 2022 05 31.
Artículo en Inglés | MEDLINE | ID: mdl-35605119

RESUMEN

Dysregulated epigenetic and transcriptional programming due to abnormalities of transcription factors (TFs) contributes to and sustains the oncogenicity of cancer cells. Here, we unveiled the role of zinc finger protein 280C (ZNF280C), a known DNA damage response protein, as a tumorigenic TF in colorectal cancer (CRC), required for colitis-associated carcinogenesis and Apc deficiency­driven intestinal tumorigenesis in mice. Consistently, ZNF280C silencing in human CRC cells inhibited proliferation, clonogenicity, migration, xenograft growth, and liver metastasis. As a C2H2 (Cys2-His2) zinc finger-containing TF, ZNF280C occupied genomic intervals with both transcriptionally active and repressive states and coincided with CCCTC-binding factor (CTCF) and cohesin binding. Notably, ZNF280C was crucial for the repression program of trimethylation of histone H3 at lysine 27 (H3K27me3)-marked genes and the maintenance of both focal and broad H3K27me3 levels. Mechanistically, ZNF280C counteracted CTCF/cohesin activities and condensed the chromatin environment at the cis elements of certain tumor suppressor genes marked by H3K27me3, at least partially through recruiting the epigenetic repressor structural maintenance of chromosomes flexible hinge domain-containing 1 (SMCHD1). In clinical relevance, ZNF280C was highly expressed in primary CRCs and distant metastases, and a higher ZNF280C level independently predicted worse prognosis of CRC patients. Thus, our study uncovered a contributor with good prognostic value to CRC pathogenesis and also elucidated the essence of DNA-binding TFs in orchestrating the epigenetic programming of gene regulation.


Asunto(s)
Cromatina , Neoplasias Colorrectales , Represión Epigenética , Factor de Unión a CCCTC/metabolismo , Carcinogénesis/genética , Cromatina/genética , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/metabolismo , Proteínas de Unión al ADN , Histonas/genética , Histonas/metabolismo , Humanos , Pronóstico , Factores de Transcripción , Dedos de Zinc
3.
J Am Chem Soc ; 146(42): 28635-28641, 2024 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-39382962

RESUMEN

The advantages of ammonia as a hydrogen carrier have led to proposals for on-site hydrogen production through its decomposition. Rapid cold start of ammonia decomposition is crucial for applications such as ammonia-powered vehicles, but conventional heating methods are challenged by the high decomposition temperature of ammonia. In this study, we successfully achieved the rapid cold start of ammonia decomposition using Co nanoparticle catalysts driven by magnetic induction heating, demonstrating excellent catalytic performance and stability. The magnetic induction heating-driven ammonia decomposition system was integrated with a hydrogen fuel cell, proving its ability to achieve the cold start of ammonia decomposition within 10 s, as demonstrated by comparative experiments using 75% H2-25% N2 from a gas cylinder as the control. This study provides a deeper understanding of hysteresis heating catalysis, promoting the practical use of ammonia as a hydrogen carrier for rapid hydrogen production in the energy industry.

4.
Anal Chem ; 96(39): 15631-15639, 2024 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-39287125

RESUMEN

In this study, we present an innovative "click-to-release" strategy for the design of highly specific H2Sn bioorthogonal probes that undergo a specific click reaction with H2Sn and release fluorophores by a following rearrangement. A library of cyclooctyne derivatives was established and successfully demonstrated the availability of the release strategy. Then, a model probe CM-CT was synthesized, which can achieve effective fluorophore release (>80%) in the presence of a H2Sn donor. To further validate the application of this class of probes, a new probe QN-RHO-CT based on Rhodamine 110 was developed. This probe showed good water solubility (>160 µM) and fast release kinetics and can achieve selective H2Sn detection in living cells. We used this probe to study the process of H2S-mediated protein S-persulfidation and demonstrated that excess H2S would directly react with protein persulfides to generate H2S2 and reduce the persulfides to thiols. Additionally, we elucidated the click-to-release mechanism in our design through a detailed mechanistic study, confirming the generation of the key intermediate α, ß-unsaturated cyclooctanethione. This bioorthogonal click-to-release reaction provides a useful tool for investigating the function of H2Sn and paves the way for biological studies on H2Sn.


Asunto(s)
Química Clic , Colorantes Fluorescentes , Sulfuros , Sulfuros/química , Colorantes Fluorescentes/química , Colorantes Fluorescentes/síntesis química , Humanos , Células HeLa , Sulfuro de Hidrógeno/análisis , Sulfuro de Hidrógeno/química , Rodaminas/química
5.
Biochem Biophys Res Commun ; 733: 150733, 2024 11 12.
Artículo en Inglés | MEDLINE | ID: mdl-39332157

RESUMEN

BACKGROUND: Obesity is a significant global public health issue linked to numerous chronic diseases, including diabetes, cardiovascular conditions, and various cancers. The vacuolar H + ATPase, a multi-subunit enzyme complex involved in maintaining pH balance, has been implicated in various health conditions, including obesity-related diseases. METHOD: This study conducts a comprehensive analysis of V-ATPase subunits' roles in adipogenesis within the context of obesity, using knockdown and RNAseq technologies. RESULT: This study conducts a comprehensive analysis of V-ATPase subunits' roles in adipogenesis, highlighting specific subunits, v0d2 and v1a, which show significant expression alterations. Our findings reveal that v1a plays a crucial role in adipocyte differentiation through pathways related to steroid and cholesterol metabolism. CONCLUSION: This study provides a comprehensive analysis of the roles played by V-ATPase subunits in adipogenesis and finds the critical role of V-ATPase subunits, particularly v1a, in the differentiation of adipocytes and their potential impact on obesity.


Asunto(s)
Adipocitos , Adipogénesis , Diferenciación Celular , Ratones Obesos , Obesidad , ATPasas de Translocación de Protón Vacuolares , Animales , ATPasas de Translocación de Protón Vacuolares/metabolismo , ATPasas de Translocación de Protón Vacuolares/genética , Ratones , Adipocitos/metabolismo , Adipocitos/citología , Obesidad/metabolismo , Obesidad/patología , Obesidad/genética , Adipogénesis/genética , Subunidades de Proteína/metabolismo , Subunidades de Proteína/genética , Células 3T3-L1 , Ratones Endogámicos C57BL
6.
BMC Plant Biol ; 24(1): 810, 2024 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-39198734

RESUMEN

BACKGROUND: The transposons of the hAT superfamily are the most widespread transposons ever known. SLEEPER genes encode domesticated transposases from the hAT superfamily, which may have lost their transposable functions during long-term evolution and transformed into host proteins that regulate plant growth and development. RESULTS: This study identified 162 members of the SLEEPER gene family from Brassica napus. These members are widely distributed on 19 chromosomes, mainly in the Cn subgenome, and have promoters with various cis-acting elements related to hormone regulation, abiotic stress, and growth and development regulation. Most of the genes in this family contain similar conserved domains and motifs, and the closer the genes are distributed on evolutionary branches, the more similar their structures are. Transcriptome sequencing performed on tissues at different growth stages from B. napus line 3529 indicated that these genes had different expression patterns, and nearly half of the genes were not detectably expressed in all samples. CONCLUSIONS: This study investigated the gene structure, expression patterns, evolutionary features, and gene localization of the SLEEPER family members to confirm the significance of these genes in the growth of B. napus, providing a reference for the study of transposon domestication and outstanding genetic resources for the genetic improvement of B. napus.


Asunto(s)
Brassica napus , Elementos Transponibles de ADN , Regulación de la Expresión Génica de las Plantas , Familia de Multigenes , Brassica napus/genética , Brassica napus/metabolismo , Elementos Transponibles de ADN/genética , Genoma de Planta , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Genes de Plantas , Filogenia , Transposasas/genética , Transposasas/metabolismo , Evolución Molecular , Perfilación de la Expresión Génica
7.
J Biomed Sci ; 31(1): 50, 2024 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-38741159

RESUMEN

BACKGROUND: G-quadruplex DNA (G4) is a non-canonical structure forming in guanine-rich regions, which play a vital role in cancer biology and are now being acknowledged in both nuclear and mitochondrial (mt) genome. However, the impact of G4-based targeted therapy on both nuclear and mt genome, affecting mt function and its underlying mechanisms remain largely unexplored. METHODS: The mechanisms of action and therapeutic effects of a G4-binding platinum(II) complex, Pt-ttpy, on mitochondria were conducted through a comprehensive approaches with in vitro and in vivo models, including ICP-MS for platinum measurement, PCR-based genetic analysis, western blotting (WB), confocal microscope for mt morphology study, extracellular flux analyzer, JC1 and Annexin V apoptosis assay, flow cytometry and high content microscope screening with single-cell quantification of both ROS and mt specific ROS, as well as click-chemistry for IF study of mt translation. Decipher Pt-ttpy effects on nuclear-encoded mt related genes expression were undertaken via RNA-seq, Chip-seq and CUT-RUN assays. RESULTS: Pt-ttpy, shows a highest accumulation in the mitochondria of A2780 cancer cells as compared with two other platinum(II) complexes with no/weak G4-binding properties, Pt-tpy and cisplatin. Pt-ttpy induces mtDNA deletion, copy reduction and transcription inhibition, hindering mt protein translation. Functional analysis reveals potent mt dysfunction without reactive oxygen species (ROS) induction. Mechanistic study provided first evidence that most of mt ribosome genes are highly enriched in G4 structures in their promoter regions, notably, Pt-ttpy impairs most nuclear-encoded mt ribosome genes' transcription through dampening the recruiting of transcription initiation and elongation factors of NELFB and TAF1 to their promoter with G4-enriched sequences. In vivo studies show Pt-ttpy's efficient anti-tumor effects, disrupting mt genome function with fewer side effects than cisplatin. CONCLUSION: This study underscores Pt-ttpy as a G4-binding platinum(II) complex, effectively targeting cancer mitochondria through dual action on mt and nuclear G4-enriched genomes without inducing ROS, offering promise for safer and effective platinum-based G4-targeted cancer therapy.


Asunto(s)
G-Cuádruplex , Mitocondrias , G-Cuádruplex/efectos de los fármacos , Humanos , Mitocondrias/metabolismo , Mitocondrias/efectos de los fármacos , Línea Celular Tumoral , Genoma Mitocondrial , Antineoplásicos/farmacología , Neoplasias/tratamiento farmacológico , Neoplasias/genética , Neoplasias/metabolismo , Platino (Metal)/farmacología , Animales
8.
Org Biomol Chem ; 22(37): 7649-7658, 2024 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-39190450

RESUMEN

The first asymmetric synthesis of (-)-penostatins B and D and the practical synthesis of (+)-penostatins A and C have been accomplished through a flexible strategy. The features of the synthesis are a BF3·OEt2-mediated Diels-Alder reaction of chiral dienophiles and methylcyclopentadienes with high chemo-, regio-, and stereoselectivity, followed by ozonolysis to install the common trisubstituted cyclopentane intermediate, and a hetero-Diels-Alder reaction with easily tunable facial selectivity, followed by sulfonate elimination to construct both enantiomeric tricyclic systems for penostatins A/C and B/D, respectively.

9.
Bioorg Med Chem ; 108: 117776, 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38852257

RESUMEN

Myocardial ischemia/reperfusion (MI/R) is a common cardiovascular disease that seriously affects the quality of life and prognosis of patients. In recent years, matrine has attracted widespread attention in the treatment of cardiovascular diseases. This study designed, synthesized, and characterized 20 new matrine derivatives and studied their protective effects on ischemia-reperfusion injury through in vivo and in vitro experiments. Based on cellular assays, most newly synthesized derivatives have a certain protective effect on Hypoxia/Reoxygenation (H/R) induced H9C2 cell damage, with compound 22 having the best activity and effectively reducing cell apoptosis and necrosis. In vitro experimental data shows that compound 22 can significantly reduce the infarct size of rat myocardium and improve cardiac function after MI/R injury. In summary, compound 22 is a new potential cardioprotective agent that can promote angiogenesis and enhance antioxidant activity by activating ADCY5, CREB3l4, and VEGFA, thereby protecting myocardial cell apoptosis and necrosis induced by MI/R.


Asunto(s)
Alcaloides , Apoptosis , Diseño de Fármacos , Matrinas , Daño por Reperfusión Miocárdica , Quinolizinas , Ratas Sprague-Dawley , Alcaloides/farmacología , Alcaloides/química , Alcaloides/síntesis química , Animales , Quinolizinas/farmacología , Quinolizinas/síntesis química , Quinolizinas/química , Daño por Reperfusión Miocárdica/tratamiento farmacológico , Daño por Reperfusión Miocárdica/patología , Ratas , Apoptosis/efectos de los fármacos , Masculino , Relación Estructura-Actividad , Estructura Molecular , Cardiotónicos/farmacología , Cardiotónicos/síntesis química , Cardiotónicos/química , Relación Dosis-Respuesta a Droga , Línea Celular , Neovascularización Fisiológica/efectos de los fármacos , Angiogénesis
10.
Thromb J ; 22(1): 64, 2024 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-39014396

RESUMEN

BACKGROUND: The association of low-density lipoprotein cholesterol (LDL-C) and lymphocyte counts with the development of deep vein thrombosis (DVT) has been demonstrated in many fields but remains lacking in open wedge high tibial osteotomy (OWHTO). This study aimed to assess the predictive value of LDL-C to lymphocyte count ratio (LLR) in screening for postoperative new-onset DVT. METHODS: Clinical data were retrospectively collected from patients who underwent OWHTO between June 2018 and May 2023. The limited restricted cubic spline (RCS) was conducted to evaluate the nonlinear relationship between LLR and the risk of postoperative new-onset DVT. The receiver operating characteristic (ROC) curves were plotted and the predictive value of biomarkers was assessed. After adjusting for intergroup confounders by propensity score matching, the univariate logistic regression was applied to assess the association between LLR and DVT. RESULTS: 1293 eligible patients were included. RCS analysis showed a linear positive correlation between LLR and the risk of DVT (P for overall = 0.008). We identified LLR had an area under the curve of 0.607, accuracy of 74.3%, sensitivity of 38.5%, and specificity of 80.7%, and LLR > 1.75 was independently associated with a 1.45-fold risk of DVT (95% CI: 1.01-2.08, P = 0.045). Furthermore, significant heterogeneities were observed in the subgroups of age, BMI, diabetes mellitus, hypertension, Kellgren-Lawrence grade, the American Society of Anesthesiologists (ASA) score, and intraoperative osteotomy correction size. CONCLUSION: LLR is a valuable biomarker for predicting postoperative new-onset DVT in patients with OWHTO, and routine screening is expected to yield positive benefits.

11.
Bioorg Chem ; 143: 107069, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38160477

RESUMEN

Tetrandrine (TET) possesses multiple pharmacological activities and could suppress tumor proliferation via PI3K pathway inhibition. However, inferior antitumor activity and potential toxicity limit its clinical application. In the present study, a series of 14-sulfonamide and sulfonate TET derivatives were designed, synthesized, and evaluated for biological activities. Through structural-activity relationship studies, compound 3c with α, ß-unsaturated carbonyl group exhibited the most potent activity against all tested tumor cell lines (including Hela, HCT116, HepG2, MCF-7, and SHSY5Y), as well as negligible toxicity against normal cell lines LO2 and HEK293. Additionally, compound 3c effectively inhibited HCT116 and CT26 cell proliferation in vitro with increased cell proportion in the G2/M phase, activated the mitochondrial apoptosis pathway, and induced colon cancer cell apoptosis by suppressing the PI3K/AKT/mTOR pathway. The further molecular docking results confirmed that compound 3c is potentially bound to multiple residues in PI3K with a stronger binding affinity than TET. Ultimately, compound 3c dramatically suppressed tumor growth in the CT26 xenograft tumor model, without noticeable visceral toxicity detected in the high-dose group. In summary, compound 3c might present new insights for designing new PI3K inhibitors and be a potential candidate for colon cancer treatment.


Asunto(s)
Bencilisoquinolinas , Neoplasias del Colon , Proteínas Proto-Oncogénicas c-akt , Humanos , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal , Fosfatidilinositol 3-Quinasas/metabolismo , Simulación del Acoplamiento Molecular , Células HEK293 , Serina-Treonina Quinasas TOR/metabolismo , Línea Celular Tumoral , Apoptosis , Proliferación Celular , Neoplasias del Colon/tratamiento farmacológico , Neoplasias del Colon/metabolismo
12.
Arch Pharm (Weinheim) ; 357(10): e2400274, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39031554

RESUMEN

Tetrandrine (TET) is a natural bis-benzylisoquinoline alkaloid isolated from Stephania species with a wide range of biological and pharmacologic activities; it mainly serves as an anti-inflammatory agent or antitumor adjuvant in clinical applications. However, limitations such as prominent hydrophobicity, severe off-target toxicity, and low absorption result in suboptimal therapeutic outcomes preventing its widespread adoption. Nanoparticles have proven to be efficient devices for targeted drug delivery since drug-carrying nanoparticles can be passively transported to the tumor site by the enhanced permeability and retention (EPR) effects, thus securing a niche in cancer therapies. Great progress has been made in nanocarrier construction for TET delivery due to their outstanding advantages such as increased water-solubility, improved biodistribution and blood circulation, reduced off-target irritation, and combinational therapy. Herein, we systematically reviewed the latest advancements in TET-loaded nanoparticles and their respective features with the expectation of providing perspective and guidelines for future research and potential applications of TET.


Asunto(s)
Bencilisoquinolinas , Disponibilidad Biológica , Nanopartículas , Solubilidad , Bencilisoquinolinas/química , Bencilisoquinolinas/administración & dosificación , Bencilisoquinolinas/farmacología , Bencilisoquinolinas/farmacocinética , Humanos , Nanopartículas/química , Animales , Portadores de Fármacos/química , Sistemas de Liberación de Medicamentos , Distribución Tisular , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/farmacología , Antineoplásicos Fitogénicos/administración & dosificación
13.
Angew Chem Int Ed Engl ; 63(31): e202402265, 2024 Jul 29.
Artículo en Inglés | MEDLINE | ID: mdl-38760991

RESUMEN

The single-unit monomer insertion (SUMI), derived from living/controlled polymerization, can be directly functionalized at the end or within the chain of polymers prepared by living/controlled polymerization, offering potential applications in the preparation of polymers with complex architectures. Many scenarios demand the simultaneous incorporation of monomers suitable for different polymerization methods into complex polymers. Therefore, it becomes imperative to utilize SUMI technologies with diverse mechanisms, especially those that are compatible with each other. Here, we reported the orthogonal SUMI technique, seamlessly combining radical and cationic SUMI approaches. Through the careful optimization of monomer and chain transfer agent pairs and adjustments to reaction conditions, we can efficiently execute both radical and cationic SUMI processes in one pot without mutual interference. The utilization of orthogonal SUMI pairs facilitates the integration of radical and cationic reversible addition-fragmentation chain transfer (RAFT) polymerization in various configurations. This flexibility enables the synthesis of diblock, triblock, and star polymers that incorporate both cationically and radically polymerizable monomers. Moreover, we have successfully implemented a mixing mechanism of free radicals and cations in RAFT step-growth polymerization, resulting in the creation of a side-chain sequence-controlled polymer brushes.

14.
Angew Chem Int Ed Engl ; : e202415044, 2024 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-39313948

RESUMEN

Electrocatalytic oxidation of C-H bonds in hydrocarbons represents an efficient and sustainable strategy for the synthesis of value-added chemicals. Herein, a highly selective and continuous-flow electrochemical oxidation process of toluene to various oxygenated products (benzyl alcohol, benzaldehyde, and benzyl acetate) is developed with the electrocatalytic membrane electrodes (ECMEs). The selectivity of target products can be manipulated via surface and interface engineering of Co3O4-based electrocatalysts. We achieved a high benzaldehyde selectivity of 90 % at a toluene conversion of 47.6 % using 1D Co3O4 nanoneedles (NNs) loaded on a microfiltration (MF) titanium (Ti) membrane, i.e, Co3O4 NNs/Ti. In contrast, the main product shifted to benzyl alcohol with a selectivity of 90.1 % at a conversion of 32.1 % after modifying MnO2 nanosheets (NSs) on Co3O4 NNs/Ti (Co3O4@MnO2/Ti) catalyst. Moreover, benzyl acetate product can be obtained with a selectivity of 92 % at a conversion of 58.5 % at high current density (>1.5 mA cm-2), demonstrating that the pathway of toluene oxidation is readily maneuvered. DFT results reveal that modifying MnO2 on Co3O4 optimizes the electron structure of Co3O4@MnO2/Ti and modulates the adsorption behavior of intermediate species. This work demonstrates a sustainable, efficient, and continuous-flow process for precise control over the production selectivity of value-added oxygenated derivatives in the electrochemical oxidation of aromatic hydrocarbons.

15.
J Am Chem Soc ; 145(34): 18800-18811, 2023 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-37590178

RESUMEN

Supramolecular electronics provide an opportunity to introduce molecular assemblies into electronic devices through a combination of noncovalent interactions such as [π···π] and hydrogen-bonding interactions. The fidelity and dynamics of noncovalent interactions hold considerable promise when it comes to building devices with controllable and reproducible switching functions. Here, we demonstrate a strategy for building electronically robust switches by harnessing two different noncovalent interactions between a couple of pyridine derivatives. The single-supermolecule switch is turned ON when compressing the junction enabling [π···π] interactions to dominate the transport, while the switch is turned OFF by stretching the junction to form hydrogen-bonded dimers, leading to a dramatic decrease in conductance. The robustness and reproducibility of these single-supermolecule switches were achieved by modulating the junction with Ångström precision at frequencies of up to 190 Hz while obtaining high ON/OFF ratios of ∼600. The research presented herein opens up an avenue for designing robust bistable mechanoresponsive devices which will find applications in the building of integrated circuits for microelectromechanical systems.

16.
J Am Chem Soc ; 145(38): 20936-20942, 2023 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-37703050

RESUMEN

The exploration of non-noble metal catalysts for alkane dehydrogenation and their catalytic mechanisms is the priority in catalysis research. Here, we report a high-density coordinatively unsaturated Zn cation (Zncus) catalyst for the direct dehydrogenation (DDH) of ethylbenzene (EB) to styrene (ST). The catalyst demonstrated good catalytic performance (∼40% initial EB conversion rate and >98% ST selectivity) and excellent regeneration ability in the reaction, which is attributed to the high-density (HD) distribution and high-stability structure of Zncus active sites on the surface of zinc silicate (HD-Zncus@ZS). Density functional theory (DFT) calculations further illustrated the reaction pathway and intermediates, supporting that the Zncus sites can efficiently activate the C-H bond of ethyl on ethylbenzene. Developing the high-density Zncus catalyst and exploring the catalytic mechanism laid a good foundation for designing practical non-noble metal catalysts.

17.
Cerebrovasc Dis ; 52(2): 202-209, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36219949

RESUMEN

BACKGROUND: Acute ischemic stroke due to basilar artery occlusion (BAO) is associated with the highest mortality in patients with large vessel occlusion. This study aimed to identify modifiable risk factors of early mortality in patients with BAO. METHODS AND RESULTS: This was a cohort study of consecutive patients with BAO admitted to 47 stroke centers in China between January 2014 and May 2019. The primary outcome was all-cause mortality within 7 days after hospitalization. Of 829 patients, 164 died (0-3 days: 115; 4-7 days: 49) within 7 days after hospitalization. Among pre- and periprocedural variables, higher admission National Institutes of Health Stroke Scale (NIHSS, adjusted OR, 1.06, 95% CI: 1.04-1.09; p < 0.001), lower admission posterior circulation-Alberta Stroke Program Early Computed Tomography Score (pc-ASPECTS, adjusted OR, 0.88, 95% CI: 0.79-0.98; p = 0.02), lower Basilar Artery on Computed Tomography Angiography score (BATMAN, adjusted OR, 0.84, 95% CI: 0.76-0.93; p = 0.001), and recanalization failure (adjusted OR, 2.99, 95% CI: 2.04-4.38; p < 0.001) were independently associated with a higher risk of early mortality. Herniation (adjusted OR, 2.84, 95% CI: 1.52-5.30; p = 0.001) is an independent postprocedural predictor of early mortality. In patients dying ≤3 days, higher NIHSS (p < 0.001), lower pc-ASPECTS (p = 0.01), lower BATMAN (p = 0.004), recanalization failure (p < 0.001), herniation (p = 0.001), gastrointestinal hemorrhage (p = 0.046), and absence of pneumonia (p < 0.001) were independent predictors of early mortality. Higher NIHSS (p = 0.01), recanalization failure (p < 0.001), and pneumonia (p = 0.03) were independently associated with early mortality between 4 and 7 days. CONCLUSIONS: Recanalization failure, herniation, gastrointestinal hemorrhage, and pneumonia are potentially modifiable risk factors for early mortality in basilar artery occlusion.


Asunto(s)
Arteriopatías Oclusivas , Procedimientos Endovasculares , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Insuficiencia Vertebrobasilar , Humanos , Arteria Basilar , Accidente Cerebrovascular Isquémico/etiología , Estudios de Cohortes , Resultado del Tratamiento , Estudios Retrospectivos , Arteriopatías Oclusivas/etiología , Procedimientos Endovasculares/efectos adversos , Trombectomía/efectos adversos
18.
Knee Surg Sports Traumatol Arthrosc ; 31(11): 4724-4734, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37378681

RESUMEN

PURPOSE: This study aimed to identify independent risk factors for immediate postoperative deep vein thrombosis (DVT) in patients with open wedge high tibial osteotomy (OWHTO) and to develop and validate a predictive nomogram. METHODS: Patients who underwent OWHTO for knee osteoarthritis (KOA) from June 2017 to December 2021 were retrospectively analyzed. Baseline data and laboratory test results were collected, and the occurrence of DVT in the immediate postoperative period was regarded as the study outcome event. Multivariable logistic regression identified independent risk factors associated with a higher incidence of immediate postoperative DVT. The predictive nomogram was constructed based on the analysis results. The stability of the model was further assessed in this study using patients from January to September 2022 as an external validation set. RESULTS: 741 patients were enrolled in the study, of which 547 were used in the training cohort and the other 194 for the validation cohort. Multivariate analysis revealed a higher Kellgren-Lawrence (K-L) grade (III vs. I-II OR 3.09, 95% CI 0.93-10.23. IV vs. I-II OR 5.23, 95% CI 1.27-21.48.), platelet to hemoglobin ratio (PHR) > 2.25 (OR 6.10, 95% CI 2.43-15.33), Low levels of albumin (ALB) (OR 0.79, 95% CI 0.70-0.90), LDL-C > 3.40 (OR 3.06, 95% CI 1.22-7.65), D-dimer > 1.26 (OR 2.83, 95% CI 1.16-6.87) and BMI ≥ 28 (OR 2.57, 95% CI 1.02-6.50) were the independent risk factors of immediate postoperative DVT. The concordance index (C-index) and Brier score of the nomogram were 0.832 and 0.036 in the training set, and the corrected values after internal validation were 0.795 and 0.038, respectively. The receiver-operating characteristic (ROC) curve, the calibration curve, the Hosmer-Lemeshow test, and the decision curve analysis (DCA) performed well in both the training and validation cohorts. CONCLUSION: This study developed a personalized predictive nomogram with six predictors, which allows surgeons to stratify risk and recommended immediate ultrasound scans for patients with any of these factors. LEVEL OF EVIDENCE: III.

19.
J Environ Manage ; 344: 118646, 2023 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-37481916

RESUMEN

Mining activities induce some social problems, such as polluted environments, the destruction of aquatic live, which have long been debated by scholars and practitioners. To mitigate this problem, underpinning dynamic capability view, our study explores whether the digital transformation (DT) affects corporate social responsibility (CSR) by using 1308 Chinese mining A-shared listed firms from 2010 to 2021, and how the potential relationship is moderated by environmental uncertainty (EU) and supply chain concentration (SCC). Applying fixed effects regressions, we find that DT fosters CSR in the mining industry, but CSR performance is weakened when DT processed at higher EU and SCC respectively. Our findings enrich the literature on CSR of mining industry and highlight that DT is an important driver that shapes CSR practice.


Asunto(s)
Tecnología Digital , Minería , Responsabilidad Social , Desarrollo Sostenible , China
20.
Angew Chem Int Ed Engl ; 62(28): e202304219, 2023 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-37195571

RESUMEN

The utilization of carbon resources stored in plastic polymers through chemical recycling and upcycling is a promising approach for mitigating plastic waste. However, most current methods for upcycling suffer from limited selectivity towards a specific valuable product, particularly when attempting full conversion of the plastic. We present a highly selective reaction route for transforming polylactic acid (PLA) into 1,2-propanediol utilizing a Zn-modified Cu catalyst. This reaction exhibits excellent reactivity (0.65 g gcat -1 h-1 ) and selectivity (99.5 %) towards 1,2-propanediol, and most importantly, can be performed in a solvent-free mode. Significantly, the overall solvent-free reaction is an atom-economical reaction with all the atoms in reactants (PLA and H2 ) fixed into the final product (1,2-propanediol), eliminating the need for a separation process. This method provides an innovative and economically viable solution for upgrading polyesters to produce high-purity products under mild conditions with optimal atom utilization.

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