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1.
Opt Express ; 32(1): 499-510, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38175078

RESUMO

We explore the prospects of phase-modulated optical nonreciprocity and enhanced ground-state cooling of a mechanical resonator for the reversed-dissipation system, where the dissipative coupling between two cavities is realized through the adiabatic elimination of a low-Q mechanical mode, while a high-Q mechanical mode interacts with two mutually coupled cavities, forming a closed-loop structure. This unique system facilitates the nontrivial phenomenon of optomechanically induced transparency (OMIT), which exhibits asymmetry due to the frequency shift effect. We also observe the emergence of parity-dependent unidirectional OMIT windows (appearing under the phase-matching condition), which can be dynamically modulated by both the phase factors and the strength of the dissipative coupling. Furthermore, our study delves into the ground-state cooling effect operating within the reversed-dissipation regime. Intriguingly, the cooling effect can be significantly enhanced by carefully engineering dissipative complex coupling, such as in the phase-matching condition. The potential applications of this scheme extend to the fabrication of ideal optical isolators in optical communication systems and the manipulation of macroscopic mechanical resonators at the quantum level, presenting exciting opportunities in quantum technologies.

2.
BMC Nephrol ; 24(1): 315, 2023 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-37884898

RESUMO

BACKGROUND: To construct and validate a risk assessment model for acute kidney injury (AKI) in patients with acute pancreatitis (AP) in the intensive care unit (ICU). METHODS: A total of 963 patients diagnosed with acute pancreatitis (AP) from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database was included. These patients were randomly divided into training set (N = 674) and validation set (N = 289) at a ratio of 7:3. Clinical characteristics were utilized to establish a nomogram for the prediction of AKI during ICU stay. These variables were selected by the least absolute shrinkage and selection operation (LASSO) regression and included in multivariate logistic regression analysis. Variables with P-values less than 0.05 were included in the final model. A nomogram was constructed based on the final model. The predicted accuracy of the nomogram was assessed by calculating the receiver operating characteristic curve (ROC) and the area under the curve (AUC). Moreover, calibration curves and Hosmer-Lemeshow goodness-of-fit test (HL test) were performed to evaluate model performance. Decision curve analysis (DCA) evaluated the clinical net benefit of the model. RESULTS: A multivariable model that included 6 variables: weight, SOFA score, white blood cell count, albumin, chronic heart failure, and sepsis. The C-index of the nomogram was 0.82, and the area under the receiver operating characteristic curve (AUC) of the training set and validation set were 0.82 (95% confidence interval:0.79-0.86) and 0.76 (95% confidence interval: 0.70-0.82), respectively. Calibration plots showed good consistency between predicted and observed outcomes in both the training and validation sets. DCA confirmed the clinical value of the model and its good impact on actual decision-making. CONCLUSION: We identified risk factors associated with the development of AKI in patients with AP. A risk prediction model for AKI in ICU patients with AP was constructed, and improving the treatment strategy of relevant factors in the model can reduce the risk of AKI in AP patients.


Assuntos
Injúria Renal Aguda , Pancreatite , Humanos , Doença Aguda , Injúria Renal Aguda/diagnóstico , Injúria Renal Aguda/epidemiologia , Unidades de Terapia Intensiva , Pancreatite/diagnóstico , Estudos Retrospectivos , Medição de Risco
3.
Mar Drugs ; 19(7)2021 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-34202523

RESUMO

Two new diterpenoids, hypoxyterpoids A (1) and B (2), and four new isocoumarin derivatives, hypoxymarins A-D (4-7), together, with seven known metabolites (3 and 8-13) were obtained from the crude extract of the mangrove-derived fungus Hypoxylon sp. The structures of the new compounds were elucidated on the basis of 1- and 2-dimensional (1D/2D) nuclear magnetic resonance (NMR) spectroscopic and mass spectrometric analysis. The absolute configurations of compounds 1, 2, 4, 5, and 7 were determined by comparison of experimental and calculated electronic circular dichroism (ECD) spectra, and the absolute configurations of C-4' in 6 and C-9 in 7 were determined by [Rh2(OCOCF3)4]-induced ECD spectra. Compound 1 showed moderate α-glucosidase inhibitory activities with IC50 values of 741.5 ± 2.83 µM. Compounds 6 and 11 exhibited DPPH scavenging activities with IC50 values of 15.36 ± 0.24 and 3.69 ± 0.07 µM, respectively.


Assuntos
Diterpenos/farmacologia , Fungos , Inibidores de Glicosídeo Hidrolases/farmacologia , Isocumarinas/farmacologia , Organismos Aquáticos , Diterpenos/química , Humanos , Concentração Inibidora 50 , Isocumarinas/química , Estrutura Molecular , Áreas Alagadas
4.
Cell Death Discov ; 8(1): 319, 2022 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-35831301

RESUMO

The underlying mechanism by which growth factor receptor-bound protein 2 (Grb2) regulates necroptosis remains unexplored. In the present study, we found that rasfonin, a fungal natural product and an activator of necroptosis, enhanced Grb2 binding to receptor-interacting serine/threonine kinase 1 (RIP1), which plays a critical role in regulating programmed necrosis. Moreover, we observed that SQSTM/p62 (p62), a protein that can form necrosomes with RIP1, increased its interaction with Grb2 upon rasfonin challenge. Although it has been used as an activator of autophagy in our previous study, here we found that a high dose of rasfonin was able to inhibit autophagic process. Inhibition of RIP1 either chemically or genetically reversed the inhibition of rasfonin on autophagy, whereas knockdown of Grb2 markedly reduced rasfonin-induced necrosis. Additionally, we found that the compound failed to upregulate the expression of RIP1 in Grb2-deprived cells. In summary, our data revealed that Grb2 actively participated in rasfonin-induced necroptosis by interacting with the components of necrosome and mediating their expression.

5.
Front Chem ; 10: 861278, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35419345

RESUMO

Croton yanhuii (Family Euphorbiaceae) is an annual aromatic plant endemic to Yunnan Province, China, which yields an aromatic, spicy oil used as a flavoring and fragrance. The aim of the present study was to acquire secondary metabolites from the leaves and twigs of C. yanhuii and to evaluate their cytotoxic activity. Five new diterpenoids, croyanhuins A-E (1-5), and one new C13 nor-isoprenoid, croyanhuin F (6), were isolated from the leaves and twigs of C. yanhuii. Their structures and absolute configurations were determined by extensive spectroscopic methods (1D and 2D NMR, IR, and HRESIMS) and confirmed by electronic circular dichroism (ECD) spectra or single-crystal X-ray diffraction analysis. Among the new terpenoids, compounds 1 and 3 inhibited cell proliferation and viability in a dose- and time-dependent manner, whereas both induced cleavage of either caspase-3 or PARP-1 in the SW480 cell line. Additionally, we observed that Z-YVAD-FMK and Z-VAD-FMK, two caspase inhibitors, inhibited the compound-dependent cell viability loss, suggesting that either of them can induce pyroptosis and caspase-dependent apoptosis. These biological assay results revealed that compounds 1 and 3 induce different kinds of programmed cell death in SW480 cells.

6.
Nat Prod Res ; 36(9): 2306-2313, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-33089720

RESUMO

A new highly oxygenated germacranolide, carcerlane A (1), together with four known highly oxygenated germacranolides (2-5), was isolated from an ethanol extract of the whole plant of Carpesium nepalense var. lanatum (C.B.Clarke) Kitam. The structures were determined by HRESIMS and extensive analysis of their spectroscopic data including IR, 1 D and 2 D NMR spectra. To our best knowledge, it was the first time to report the phytochemical investigation on this plant. The anti-Alzheimer's disease (AD) activities of 1-5 were evaluated using Caenorhabditis elegans AD pathological model. All the tested compounds showed that they have the anti-AD bioactivities of delaying worms paralysis.


Assuntos
Antineoplásicos Fitogênicos , Asteraceae , Antineoplásicos Fitogênicos/química , Asteraceae/química , Estrutura Molecular , Sesquiterpenos de Germacrano/química , Sesquiterpenos de Germacrano/farmacologia
7.
Fitoterapia ; 151: 104867, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33621655

RESUMO

Salvia castanea (Family Labiatae), a perennial fragrant herb with castaneous flowers, is mainly distributed in areas with an altitude of 2500-3750 m. The roots of this plant were used as a tea drink by local residents to strengthen physical health. The aim of present study was to acquire secondary metabolites of the ethanol extract obtained from the whole plant of S. castanea and to evaluate their potential anti-Alzheimer's disease. Six new sesquiterpene lactones, salcastanins A-F (1-6), together with three known guaiane-type sesquiterpenoids nubiol (7), nubdienolide (8), and nubenolide (9), were separated from the whole plant of S. castanea. The structures of these compounds were determined by HRESIMS and NMR experiments. The absolute configurations of 1-6 were ascertained by electronic circular dichroism (ECD) experiments. The humanized Caenorhabditis elegans AD pathological model was used to evaluate anti-Alzheimer's disease (AD) activities of 1-9. The results showed the compounds 1-3 and 7 significantly delayed AD-like symptoms of worm paralysis phenotype, which could be used as novel anti-AD candidates.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Extratos Vegetais/química , Salvia/química , Sesquiterpenos/farmacologia , Animais , Caenorhabditis elegans/efeitos dos fármacos , China , Modelos Animais de Doenças , Estrutura Molecular , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Sesquiterpenos/isolamento & purificação
8.
Fitoterapia ; 142: 104536, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32145310

RESUMO

Commiphoins A-C (1-3), three new cadinane-type sesquiterpenes, together with two known cadinane-type sesquiterpenes (4 and 5) were isolated from the resinous exudates of Commiphora myrrha. Their structures and relative configurations were established on the basis of comprehensive spectroscopic methods, including HRESIMS, 1D and 2D NMR analyses. Compounds 1 and 3-5 were screened for anti-Alzheimer's disease (AD) activities using the AD pathological model in Caenorhabditis elegans. The results showed that they all had significant anti-AD activities.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Commiphora/química , Sesquiterpenos Policíclicos/isolamento & purificação , Animais , Animais Geneticamente Modificados , Caenorhabditis elegans , Avaliação Pré-Clínica de Medicamentos , Sesquiterpenos Policíclicos/química , Sesquiterpenos Policíclicos/uso terapêutico , Resinas Vegetais/química
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