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1.
Nature ; 565(7737): 61-66, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30602749

RESUMO

Topological quantum materials exhibit fascinating properties1-3, with important applications for dissipationless electronics and fault-tolerant quantum computers4,5. Manipulating the topological invariants in these materials would allow the development of topological switching applications analogous to switching of transistors6. Lattice strain provides the most natural means of tuning these topological invariants because it directly modifies the electron-ion interactions and potentially alters the underlying crystalline symmetry on which the topological properties depend7-9. However, conventional means of applying strain through heteroepitaxial lattice mismatch10 and dislocations11 are not extendable to controllable time-varying protocols, which are required in transistors. Integration into a functional device requires the ability to go beyond the robust, topologically protected properties of materials and to manipulate the topology at high speeds. Here we use crystallographic measurements by relativistic electron diffraction to demonstrate that terahertz light pulses can be used to induce terahertz-frequency interlayer shear strain with large strain amplitude in the Weyl semimetal WTe2, leading to a topologically distinct metastable phase. Separate nonlinear optical measurements indicate that this transition is associated with a symmetry change to a centrosymmetric, topologically trivial phase. We further show that such shear strain provides an ultrafast, energy-efficient way of inducing robust, well separated Weyl points or of annihilating all Weyl points of opposite chirality. This work demonstrates possibilities for ultrafast manipulation of the topological properties of solids and for the development of a topological switch operating at terahertz frequencies.

2.
Nano Lett ; 24(20): 6031-6037, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38717626

RESUMO

Manipulating the polarization of light at the nanoscale is key to the development of next-generation optoelectronic devices. This is typically done via waveplates using optically anisotropic crystals, with thicknesses on the order of the wavelength. Here, using a novel ultrafast electron-beam-based technique sensitive to transient near fields at THz frequencies, we observe a giant anisotropy in the linear optical response in the semimetal WTe2 and demonstrate that one can tune the THz polarization using a 50 nm thick film, acting as a broadband wave plate with thickness 3 orders of magnitude smaller than the wavelength. The observed circular deflections of the electron beam are consistent with simulations tracking the trajectory of the electron beam in the near field of the THz pulse. This finding offers a promising approach to enable atomically thin THz polarization control using anisotropic semimetals and defines new approaches for characterizing THz near-field optical response at far-subwavelength length scales.

3.
Molecules ; 29(5)2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38474465

RESUMO

The pharmacological activity and medicinal significance of Amauroderma rugosum (AR) have rarely been documented. We examined the antioxidant and neuroprotective effects of AR on 6-hydroxydopamine (6-OHDA)-induced neurotoxicity in an SH-SY5Y human neuroblastoma cell model of Parkinson's disease (PD) and explored the active ingredients responsible for these effects. The results showed that the AR aqueous extract could scavenge reactive oxygen species and reduce SH-SY5Y cell death induced by 6-OHDA. In addition, the AR aqueous extract increased the survival of Caenorhabditis elegans upon juglone-induced toxicity. Among the constituents of AR, only polysaccharides and gallic acid exhibited antioxidant and neuroprotective effects. The AR aqueous extract reduced apoptosis and increased the expression of phospho-Akt, phospho-mTOR, phospho-MEK, phospho-ERK, and superoxide dismutase-1 in 6-OHDA-treated SH-SY5Y cells. The polysaccharide-rich AR extract was slightly more potent than the aqueous AR extract; however, it did not affect the expression of phospho-Akt or phospho-mTOR. In conclusion, the AR aqueous extract possessed antioxidant and neuroprotective properties against 6-OHDA-induced toxicity in SH-SY5Y cells. The mechanism of action involves the upregulation of the Akt/mTOR and MEK/ERK-dependent pathways. These findings indicate the potential utility of AR and its active ingredients in preventing or treating neurodegenerative disorders associated with oxidative stress such as PD.


Assuntos
Neuroblastoma , Fármacos Neuroprotetores , Doença de Parkinson , Polyporaceae , Humanos , Oxidopamina/farmacologia , Fármacos Neuroprotetores/farmacologia , Antioxidantes/farmacologia , Ácido Gálico/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Linhagem Celular Tumoral , Neuroblastoma/tratamento farmacológico , Apoptose , Espécies Reativas de Oxigênio/metabolismo , Doença de Parkinson/tratamento farmacológico , Serina-Treonina Quinases TOR , Quinases de Proteína Quinase Ativadas por Mitógeno
4.
Phytother Res ; 37(10): 4442-4456, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37259475

RESUMO

Cancer metastasis remains the most common cause of death in breast cancer patients. Tumor-associated macrophages (TAMs) are a novel therapeutic target for the treatment of metastatic breast cancer. Despite the good anti-cancer activity of garcinone E (GE), there are no reports on its therapeutic effects on breast cancer metastasis. The objective of this study was to examine the anti-cancer effects of GE on metastatic breast cancer. RAW 264.7 and THP-1 cells were polarized to M2 macrophages by IL-4/IL-13 in vitro. A 4T1 mouse breast cancer model and the tail vein breast cancer metastasis model were used to explore the effect of GE on breast cancer growth and metastasis in vivo. In vitro studies showed that GE dose-dependently suppressed IL-4 + IL-13-induced expression of CD206 in both RAW 264.7 cells and differentiated THP-1 macrophages. However, GE did not affect the LPS + IFN-γ-induced polarization to the M1-like macrophages in vitro. GE inhibited the expression of the M2 macrophage specific genes in RAW 264.7 cells, and simultaneously impaired M2 macrophage-induced breast cancer cell proliferation and migration, and angiogenesis. In animal studies, GE significantly suppressed tumor growth, angiogenesis, and lung metastasis in 4T1 tumor-bearing mice, without causing toxicity. In both tumor and lung tissues, the proportion of M2-like TAMs was significantly decreased while the proportion of M1-like TAMs was markedly increased by GE treatment. Mechanistically, GE inhibited phosphorylation of STAT6 in vitro and in vivo. Our results demonstrate for the first time that GE suppresses breast cancer growth and pulmonary metastasis by modulating M2-like macrophage polarization through the STAT6 signaling pathway.


Assuntos
Neoplasias da Mama , Humanos , Animais , Camundongos , Feminino , Neoplasias da Mama/patologia , Macrófagos Associados a Tumor , Linhagem Celular Tumoral , Interleucina-4/metabolismo , Interleucina-4/farmacologia , Interleucina-4/uso terapêutico , Interleucina-13/metabolismo , Interleucina-13/farmacologia , Interleucina-13/uso terapêutico , Transdução de Sinais , Fator de Transcrição STAT6/metabolismo , Fator de Transcrição STAT6/farmacologia
5.
Molecules ; 28(4)2023 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-36838743

RESUMO

Ganoderma lucidum has long been used as a multi-purpose plant and functional food. The pharmacological properties of G. lucidum are primarily attributed to its polysaccharides and triterpenoids. Ganoderic and lucidenic acids are the two major triterpenoids groups in G. lucidum. Despite the discovery of 22 types of lucidenic acids, research on lucidenic acids is significantly less extensive compared to that on ganoderic acid. To the best of our knowledge, for the first time, in this review, we aimed to summarize the sources, contents, chemical structures, and pharmacological effects, including anti-cancer, anti-inflammatory, antioxidant, anti-viral, neuroprotective, anti-hyperlipidemic, anti-hypercholesterolemic, and anti-diabetic properties, of lucidenic acids. Studies on lucidenic acids are still preliminary and have several limitations. Therefore, more in-depth studies with optimal designs are essential for the development of lucidenic acids as medicines, functional foods, and nutraceuticals.


Assuntos
Reishi , Triterpenos , Triterpenos/química , Reishi/química
6.
Mol Biol Rep ; 49(11): 11201-11208, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36107375

RESUMO

BACKGROUND: Nucleoside transporters are crucial in regulating the functions of adenosine. This study investigated the contribution of equilibrative nucleoside transporter (ENT) type 4 to adenosine transport in cardiomyocytes under simulated ischemic conditions and whether the inhibition of ENT4 could protect cardiomyocytes against ischemia-reperfusion injury. METHODS: AC16 human cardiomyocytes were used to create a model to simulate ischemia/reperfusion injury. ENT4 activity was inhibited by decynium-22 or specific siRNA against ENT4. The protein expressions of nucleoside transporters were measured by western blot analysis. The transport activity was studied by [3?H]adenosine uptake. The cell injury was studied by biochemical assays. RESULTS: The [3?H]adenosine uptake in AC16 cells was predominantly mediated by ENTs. ENT1 to ENT4 were present in AC16 cells and their protein expression levels were comparable in normal and ischemic conditions. Decynium-22 or siRNA against ENT4 did not affect the adenosine uptake in AC16 cells under normal conditions but could inhibit the adenosine uptake in AC16 cells by 28% under ischemic conditions. In addition, the cell viability and lactate dehydrogenase release of AC16 cells under ischemia conditions could be reduced by decynium-22 or siRNA against ENT4. CONCLUSION: The cell culture model has suggested that ENT4 may play a role in adenosine transport in cardiomyocytes under ischemic conditions. Inhibition or downregulation of ENT4 may be a potential approach for cardioprotection but this notion should be further validated using animal model.


Assuntos
Miócitos Cardíacos , Traumatismo por Reperfusão , Animais , Humanos , Miócitos Cardíacos/metabolismo , Adenosina/metabolismo , Nucleosídeos/metabolismo , RNA Interferente Pequeno/metabolismo , Traumatismo por Reperfusão/metabolismo , Isquemia
7.
Molecules ; 27(19)2022 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-36235070

RESUMO

Keratinocytes form the physical barrier of the skin and play an important role in the inflammatory process. Amauroderma rugosum is an edible mushroom; however, its pharmacological properties have seldom been studied. Although the anti-inflammatory effect of the organic solvent extract of Amauroderma rugosum has been previously reported, it is not known whether the aqueous extract has a similar effect. In addition, the effect of Amauorderma rugosum extract on skin has never been explored. Therefore, the objectives of the present study were to evaluate the anti-inflammatory effects of the aqueous extract of Amauroderma rugosum on HaCaT keratinocytes, to explore its mechanisms of action, and to study the possible active ingredients involved. The results showed that the aqueous extract of Amauroderm rugosum at a concentration of 1.5 mg/mL was non-toxic to HaCaT cells and inhibited the release of cytokine interleukin-1ß, and chemokines interleukin-8 and monocyte chemoattractant protein-1 in tumor necrosis factor (TNF)-α- and interferon (IFN)-γ-stimulated HaCaT cells. Amauroderma rugosum extract reduced the intracellular levels of reactive oxygen species. In addition, Amauroderma rugosum extract reduced the total protein expression of nuclear factor-kappa B (NF-κB) and B-cells inhibitor alpha in HaCaT keratinocytes and inhibited the phosphorylation of mitogen-activated protein kinase kinase (MEK) 1/2, extracellular signal-regulated kinase (ERK) 1/2, protein kinase B (Akt), and mammalian target of rapamycin (mTOR) in TNF-α- and INF-γ-stimulated HaCaT keratinocytes. Chemical analysis revealed that the aqueous extract of Amauroderma rugosum contains polysaccharides, triterpenes, and phenolic compounds. Anti-inflammatory compounds, such as gallic acid, guanosine, and uridine, were also present. The anti-inflammatory effect of Amauroderma rugosum could be mimicked by a combination of gallic acid, guanosine, and uridine. In conclusion, our study suggests that the aqueous extract of Amauroderma rugosum exerts anti-inflammatory effects on keratinocytes through its antioxidant and inhibitory effects on MEK/ERK-, Akt/mTOR-, and NF-κB-dependent signaling pathways.


Assuntos
Triterpenos , Fator de Necrose Tumoral alfa , Anti-Inflamatórios/metabolismo , Anti-Inflamatórios/farmacologia , Antioxidantes/farmacologia , Quimiocina CCL2/metabolismo , Quimiocinas/metabolismo , Citocinas/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Ácido Gálico/farmacologia , Guanosina/metabolismo , Interferon gama/metabolismo , Interferon gama/farmacologia , Interleucina-1beta/metabolismo , Interleucina-8/metabolismo , Queratinócitos , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , NF-kappa B/metabolismo , Polyporaceae , Proteínas Proto-Oncogênicas c-akt/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Solventes/farmacologia , Serina-Treonina Quinases TOR/metabolismo , Triterpenos/farmacologia , Fator de Necrose Tumoral alfa/metabolismo , Uridina/farmacologia
8.
Opt Express ; 29(6): 9624-9634, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33820386

RESUMO

We demonstrate a highly efficient method for the generation of a high-field terahertz (THz) pulse train via optical rectification (OR) in congruent lithium niobate (LN) crystals driven by temporally shaped laser pulses. A narrowband THz pulse has been successfully achieved with sub-percent level conversion efficiency and multi MV/cm peak field at 0.26 THz. For the single-cycle THz generation, we achieved a THz pulse with 373-µJ energy in a LN crystal excited by a 100-mJ laser pulse at room temperature. The conversion efficiency is further improved to 0.77 % pumped by a 20-mJ laser pulse with a smaller pump beam size (6 mm in horizontal and 15 mm in vertical). This method holds great potential for generating mJ-level narrow-band THz pulse trains, which may have a major impact in mJ-scale applications like terahertz-based accelerators and light sources.

9.
Phys Rev Lett ; 127(22): 227401, 2021 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-34889631

RESUMO

Engineering novel states of matter with light is at the forefront of materials research. An intensely studied direction is to realize broken-symmetry phases that are "hidden" under equilibrium conditions but can be unleashed by an ultrashort laser pulse. Despite a plethora of experimental discoveries, the nature of these orders and how they transiently appear remain unclear. To this end, we investigate a nonequilibrium charge density wave (CDW) in rare-earth tritellurides, which is suppressed in equilibrium but emerges after photoexcitation. Using a pump-pump-probe protocol implemented in ultrafast electron diffraction, we demonstrate that the light-induced CDW consists solely of order parameter fluctuations, which bear striking similarities to critical fluctuations in equilibrium despite differences in the length scale. By calculating the dynamics of CDW fluctuations in a nonperturbative model, we further show that the strength of the light-induced order is governed by the amplitude of equilibrium fluctuations. These findings highlight photoinduced fluctuations as an important ingredient for the emergence of transient orders out of equilibrium. Our results further suggest that materials with strong fluctuations in equilibrium are promising platforms to host hidden orders after laser excitation.

10.
Nano Lett ; 19(8): 4981-4989, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31260315

RESUMO

The light-induced selective population of short-lived far-from-equilibrium vibration modes is a promising approach for controlling ultrafast and irreversible structural changes in functional nanomaterials. However, this requires a detailed understanding of the dynamics and evolution of these phonon modes and their coupling to the excited-state electronic structure. Here, we combine femtosecond mega-electronvolt electron diffraction experiments on a prototypical layered material, MoTe2, with non-adiabatic quantum molecular dynamics simulations and ab initio electronic structure calculations to show how non-radiative energy relaxation pathways for excited electrons can be tuned by controlling the optical excitation energy. We show how the dominant intravalley and intervalley scattering mechanisms for hot and band-edge electrons leads to markedly different transient phonon populations evident in electron diffraction patterns. This understanding of how tuning optical excitations affect phonon populations and atomic motion is critical for efficiently controlling light-induced structural transitions of optoelectronic devices.

11.
Phys Rev Lett ; 123(9): 097601, 2019 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-31524450

RESUMO

Complex systems, which consist of a large number of interacting constituents, often exhibit universal behavior near a phase transition. A slowdown of certain dynamical observables is one such recurring feature found in a vast array of contexts. This phenomenon, known as critical slowing-down, is well studied mostly in thermodynamic phase transitions. However, it is less understood in highly nonequilibrium settings, where the time it takes to traverse the phase boundary becomes comparable to the timescale of dynamical fluctuations. Using transient optical spectroscopy and femtosecond electron diffraction, we studied a photoinduced transition of a model charge-density-wave (CDW) compound LaTe_{3}. We observed that it takes the longest time to suppress the order parameter at the threshold photoexcitation density, where the CDW transiently vanishes. This finding can be captured by generalizing the time-dependent Landau theory to a system far from equilibrium. The experimental observation and theoretical understanding of dynamical slowing-down may offer insight into other general principles behind nonequilibrium phase transitions in many-body systems.

12.
Phytochem Anal ; 30(4): 447-455, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30916852

RESUMO

INTRODUCTION: The Chinese medicine formulation, tumour-shrinking decoction (TSD, FM1523), which consists of 15 natural medicines, is used for uterine fibroids (UFs) therapy and possesses excellent clinical therapeutic effect. OBJECTIVE: To develop a sensitive and validated analytical method for the simultaneous quantification of four crucial bioactive compounds including isorhamnetin-3-O-neohesperidoside, curcumin, peimine and tetrahydropalmatine in the principal formulation of this decoction. METHODS: An ultra-performance liquid chromatography coupled tandem mass spectrometry (UPLC-MS/MS) with an electrospray ionisation (ESI) source in multiple reaction monitoring (MRM) mode was conducted to investigate these bioactive compounds in the TSD. The chromatographic separation was performed on a C18 column when the flow rate was adjusted at 0.2 mL/min with gradient elution of acetonitrile-water with 0.1% formic acid. Accelerated solvent extraction (ASE) method with higher extraction efficiency was employed for TSD sample pre-treatment. RESULTS: The linearity, limit of detection (LOD) and limit of quantification (LOQ) were determined for this analytical method. The mean recoveries of the compounds were determined between 100.23% and 104.02% with satisfactory relative standard deviation (RSD) in the ranges of 2.65% to 3.81%. The precision was evaluated by intra-day and inter-day tests, which revealed RSD within the ranges of 1.21% to 2.14% and 1.24% to 2.32%, respectively. CONCLUSION: The bioactive compounds of TSD samples were successfully quantified via UPLC-MS/MS with MRM mode. This study could help to evaluate the pharmacokinetic study of TSD during clinical applications and present a facile strategy for quantifying bioactive compounds in traditional Chinese Medicine decoction.


Assuntos
Alcaloides de Berberina/química , Cevanas/química , Medicamentos de Ervas Chinesas/química , Leiomioma/tratamento farmacológico , Compostos Fitoquímicos/química , Alcaloides de Berberina/isolamento & purificação , Cevanas/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Humanos , Limite de Detecção , Compostos Fitoquímicos/isolamento & purificação , Espectrometria de Massas em Tandem
13.
Phys Rev Lett ; 117(15): 153002, 2016 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-27768362

RESUMO

Observing the motion of the nuclear wave packets during a molecular reaction, in both space and time, is crucial for understanding and controlling the outcome of photoinduced chemical reactions. We have imaged the motion of a vibrational wave packet in isolated iodine molecules using ultrafast electron diffraction with relativistic electrons. The time-varying interatomic distance was measured with a precision 0.07 Å and temporal resolution of 230 fs full width at half maximum. The method is not only sensitive to the position but also the shape of the nuclear wave packet.

14.
Faraday Discuss ; 194: 563-581, 2016 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-27711826

RESUMO

We present results on ultrafast gas electron diffraction (UGED) experiments with femtosecond resolution using the MeV electron gun at SLAC National Accelerator Laboratory. UGED is a promising method to investigate molecular dynamics in the gas phase because electron pulses can probe the structure with a high spatial resolution. Until recently, however, it was not possible for UGED to reach the relevant timescale for the motion of the nuclei during a molecular reaction. Using MeV electron pulses has allowed us to overcome the main challenges in reaching femtosecond resolution, namely delivering short electron pulses on a gas target, overcoming the effect of velocity mismatch between pump laser pulses and the probe electron pulses, and maintaining a low timing jitter. At electron kinetic energies above 3 MeV, the velocity mismatch between laser and electron pulses becomes negligible. The relativistic electrons are also less susceptible to temporal broadening due to the Coulomb force. One of the challenges of diffraction with relativistic electrons is that the small de Broglie wavelength results in very small diffraction angles. In this paper we describe the new setup and its characterization, including capturing static diffraction patterns of molecules in the gas phase, finding time-zero with sub-picosecond accuracy and first time-resolved diffraction experiments. The new device can achieve a temporal resolution of 100 fs root-mean-square, and sub-angstrom spatial resolution. The collimation of the beam is sufficient to measure the diffraction pattern, and the transverse coherence is on the order of 2 nm. Currently, the temporal resolution is limited both by the pulse duration of the electron pulse on target and by the timing jitter, while the spatial resolution is limited by the average electron beam current and the signal-to-noise ratio of the detection system. We also discuss plans for improving both the temporal resolution and the spatial resolution.

15.
Nano Lett ; 15(10): 6889-95, 2015 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-26322659

RESUMO

Two-dimensional materials are subject to intrinsic and dynamic rippling that modulates their optoelectronic and electromechanical properties. Here, we directly visualize the dynamics of these processes within monolayer transition metal dichalcogenide MoS2 using femtosecond electron scattering techniques as a real-time probe with atomic-scale resolution. We show that optical excitation induces large-amplitude in-plane displacements and ultrafast wrinkling of the monolayer on nanometer length-scales, developing on picosecond time-scales. These deformations are associated with several percent peak strains that are fully reversible over tens of millions of cycles. Direct measurements of electron-phonon coupling times and the subsequent interfacial thermal heat flow between the monolayer and substrate are also obtained. These measurements, coupled with first-principles modeling, provide a new understanding of the dynamic structural processes that underlie the functionality of two-dimensional materials and open up new opportunities for ultrafast strain engineering using all-optical methods.

16.
J Nat Prod ; 77(3): 571-5, 2014 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-24484321

RESUMO

Ginkgolic acids (GAs; anacardic acids; 6-alkylsalicylic acids) are both unwanted constituents in standardized Ginkgo biloba (Ginkgo) extracts and desirable constituents for pharmacological assays. Thus, for the quality control of Ginkgo extracts, the availability of pure GAs is important. In this investigation, inexpensive and easily prepared Fe3O4 magnetic nanoparticles (MNPs) in methanol were used to selectively adsorb GAs from crude petroleum ether extracts of Ginkgo leaves in the presence of various lipids including other alkylphenols (cardanols and cardols). The adsorption capacity of the MNPs is high, at 4-5% (w/w). The moiety responsible for the adsorption is the salicylic acid group, which binds strongly to Fe(III). Desorption with acidified methanol gave an extract with a GA content of 73%. This could be further separated by preparative HPLC on a C8 column. In total, eight different GAs were captured by MNPs. The MNP adsorption step can replace more traditional column chromatography and liquid-liquid extraction steps and is superior in terms of solvent consumption, selectivity, labor, and energy consumption. MNPs might become an efficient separation technique for selected high-value phytochemicals that contain a salicylic acid moiety.


Assuntos
Óxido Ferroso-Férrico/química , Ginkgo biloba/química , Salicilatos/isolamento & purificação , Adsorção , Cromatografia Líquida de Alta Pressão , Nanopartículas de Magnetita , Estrutura Molecular , Folhas de Planta/química , Salicilatos/análise , Salicilatos/química
17.
Sci Rep ; 14(1): 21159, 2024 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-39256492

RESUMO

A high efficiency simulation method for propagation-based phase-contrast imaging, called directional macro-wavefront (DMWF), is developed with the aim of simulating high-energy phase-contrast imaging. This method takes both Monte Carlo and wave optical propagation into consideration. Traditional wave-optics-based simulation methods for phase-contrast imaging encounter unacceptable computational complexity when high-energy radiation is used. In contrast, this method effectively addresses this issue by using macro-wavefront integration. Several simulation examples using typical parameters of inverse Compton scattering sources are presented to illustrate the excellent energy adaptability and efficiency of the DMWF method. This method provides a more efficient approach for phase-contrast imaging simulations, which will drive the advancement of high-energy phase-contrast imaging.

18.
Heliyon ; 10(12): e33051, 2024 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-39021977

RESUMO

YH0618, a medicinal and edible formulation, has demonstrated the potential to alleviate doxorubicin-induced alopecia in animal studies and clinical trials. However, the mechanisms underlying its therapeutic effects remain unexplored. The objective of this study was to ascertain possible therapeutic targets of YH0618 in the treatment of doxorubicin-induced alopecia. The assessment of hair loss was conducted through the measurement of the proportion of the affected area and the examination of skin histology. Isobaric tags for relative and absolute quantification (iTRAQ) in quantitative proteomics was employed to discern proteins that exhibited variable expressions. The major proteins associated with doxorubicin-induced alopecia were identified using gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. The interaction network of the differentially expressed proteins was constructed using the STRING database and the Python software. The study analyzed a total of 3894 proteins extracted from the skin tissue of mice. Doxorubicin treatment resulted in the upregulation of 18 distinct proteins, whereas one differential protein was found to be downregulated. The above effects were reinstated after the administration of the YH0618 therapy. The bioinformatic study revealed that the identified proteins exhibited enrichment in many biological processes, including staphylococcus aureus infection, estrogen signaling route, pyruvate metabolism, chemical carcinogenesis, and PPAR signaling pathway. The results of Western blot revealed that the levels of keratin 81 (Krt81), keratin 34 (Krt34), keratin 33a (Krt33a), and Sma and MAD-related protein 3 (Smad3) were upregulated in response to doxorubicin treatment, and were attenuated by the administration of YH0618. These four proteins are likely to correlate with DOX-induced alopecia and serve as promising therapeutic targets for YH0618. This work presents significant insights and empirical evidence for comprehending the process underlying chemotherapy-induced alopecia, paving the way for exploring innovative therapeutic or preventive strategies employing herbal items.

19.
J Phys Chem B ; 2024 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-39268827

RESUMO

The impact of ions on water has long been a subject of great interest, as it is closely tied to the hydration structure, dynamics, and properties of electrolyte solutions. Over centuries of investigation, the influence of ions on water's structure remains highly debated. Prevailing techniques, such as neutron and X-ray scattering, primarily focus on the microscopic structure of salt solutions at very high concentrations, mostly above 1 mol/L. In this study, we measured the structure of aqueous potassium iodide (KI) and potassium chloride (KCl) solutions using MeV liquid electron scattering (MeV-LES) across a concentration range of 0.10 to 0.75 mol/L. The obtained results provide detailed insights into the variations in ion-oxygen and oxygen-oxygen correlations as a function of concentration. The observed structural differences between KI and KCl solutions are in line with the structure maker/breaker theory, which suggests that iodide ions exert a more pronounced effect than chloride ions on disrupting the water shell. This work demonstrates the potency of MeV-LES for investigating the atomic structure in liquids, augmenting the modern analytical toolbox.

20.
Int J Biol Macromol ; 271(Pt 2): 132533, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38777026

RESUMO

Amauroderma rugosum (AR), also known as "Blood Lingzhi" in Chinese, is a basidiomycete belonging to the Ganodermataceae family. Four polysaccharide fractions were systematically isolated and purified from AR. Subsequently, their compositions were examined and analyzed via high-performance gel permeation chromatography (HPGPC), analysis of the monosaccharide composition, Fourier-transform infrared spectroscopy (FT-IR), and 1H nuclear magnetic resonance (NMR). The zebrafish model was then used to screen for proangiogenic activities of polysaccharides by inducing vascular insufficiency with VEGF receptor tyrosine kinase inhibitor II (VRI). The third fraction of AR polysaccharides (PAR-3) demonstrated the most pronounced proangiogenic effects, effectively ameliorating VRI-induced intersegmental vessel deficiency in zebrafish. Concurrently, the mRNA expression levels of vascular endothelial growth factor (VEGF)-A and VEGF receptors were upregulated by PAR-3. Moreover, the proliferation, migration, invasion, and tube formation of human umbilical vein endothelial cells (HUVECs) were also stimulated by PAR-3, consistently demonstrating that PAR-3 possesses favorable proangiogenic properties. The activation of the Akt, ERK1/2, p38 MAPK, and FAK was most likely the underlying mechanism. In conclusion, this study establishes that PAR-3 isolated from Amauroderma rugosum exhibits potential as a bioresource for promoting angiogenesis.


Assuntos
Células Endoteliais da Veia Umbilical Humana , Peixe-Zebra , Animais , Humanos , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Polissacarídeos/farmacologia , Polissacarídeos/química , Fator A de Crescimento do Endotélio Vascular/metabolismo , Fator A de Crescimento do Endotélio Vascular/genética , Neovascularização Fisiológica/efeitos dos fármacos , Indutores da Angiogênese/farmacologia , Indutores da Angiogênese/química , Receptores de Fatores de Crescimento do Endotélio Vascular/metabolismo , Receptores de Fatores de Crescimento do Endotélio Vascular/genética , Basidiomycota/química , Polissacarídeos Fúngicos/farmacologia , Polissacarídeos Fúngicos/química
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