Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 149
Filtrar
1.
Postepy Dermatol Alergol ; 41(1): 113-120, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38533361

RESUMO

Introduction: Psoriasis is a T cell-mediated polygenic chronic inflammatory disease. Interleukin (IL)-17A plays a major role in psoriasis pathogenesis. Secukinumab is a high-affinity human monoclonal antibody against IL-17A. Aim: This article explored efficacy and safety of secukinumab plus tretinoin in moderate to severe psoriasis (MSP) vulgaris, and assessed metabolism, liver function, and inflammation. Material and methods: A total of 135 patients diagnosed with moderate or severe psoriasis vulgaris were enrolled and randomized into three groups at a 1 : 1 : 1 ratio, receiving treatment with rretinoin, secukinumab, or combination therapy for a duration of 16 weeks. Psoriasis area and severity index (PASI) scores, serum T lymphocyte subsets, glucose, lipid, and uric acid (UA) metabolism, liver enzymes, and inflammatory factors (IFs) were measured. Results: Following the therapy, subjects had decreased PASI scores, increased serum CD3+, CD4+, and CD4+/CD8+, decreased serum CD8+, and decreased serum UA and IL-2, IL-6, IL-23, interferon-γ (IFN-γ), and tumor necrosis factor (TNF)-α (p < 0.05). Total cholesterol, triglycerides, low-density lipoprotein, high-density lipoprotein, apolipoproteins A1, B, fasting blood glucose, alanine transaminase, aspartate transaminase, and alkaline phosphatase had no obvious differences among the subjects (p > 0.05). As against the Tretinoin and the Secukinumab groups, the PASI score was visiblysmaller, the changes in serum T lymphocyte subsets were more obvious, and serum UA and IFs were lower in the Combination group following the therapy (p < 0.05). Conclusions: Secukinumab combined with tretinoin is more effective in MSP vulgaris, which can visibly reduce inflammatory response without affecting glucose and lipid metabolism and liver function.

2.
Org Lett ; 26(8): 1612-1617, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38377309

RESUMO

The biosynthetic gene cluster responsible for the production of C2-asymmetric 16-membered dilactones, including pyrenophorol and its derivatives, was discovered through genome mining of polyketides from a sponge-derived fungus. The biosynthetic pathway of the pyrenophorol dilactones was subsequently elucidated. A distinctive flavoenzyme PylE was identified to catalyze the isomerization of the 4-alcohol-2,3-unsaturated moiety within the dilactone scaffold, resulting in the formation of a 1,4-diketone. Further insights into the catalytic mechanism of PylE were obtained through mutagenesis experiments combined with molecular docking.


Assuntos
Compostos Heterocíclicos , Isomerismo , Cetonas , Osteocondrodisplasias , Simulação de Acoplamento Molecular , Catálise
3.
Chem Biodivers ; 21(4): e202302069, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38246882

RESUMO

Two new dihydroisocoumarins, exserolides L and M (1 and 2), along with six known compounds (3-8) were isolated from the extract of the marine-sponge-derived fungus Setosphaeria sp. SCSIO41009. Their structures were established by spectroscopic analyses. The absolute configurations of two new compounds were determined by modified Mosher's method and ECD data. Compounds 1 and 4 showed significant antiviral activities against A/Puerto Rico/8/34 H274Y (H1 N1) with IC50 values of 4.07±0.76 µM and 20.06±4.85 µM, respectively.


Assuntos
Ascomicetos , Isocumarinas , Estrutura Molecular , Isocumarinas/química , Ascomicetos/química
4.
Mar Drugs ; 21(11)2023 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-37999391

RESUMO

The coral-derived fungus Aspergillus austwickii SCSIO41227 from Beibu Gulf yielded four previously uncharacterized compounds, namely asperpentenones B-E (1-4), along with twelve known compounds (5-16). Their structures were elucidated using HRESIMS and NMR (1H and 13C NMR, HSQC, HMBC), among which the stereo-structure of compounds 1-3 was determined by calculated ECD. Furthermore, compounds 1-16 were evaluated in terms of their enzyme (acetylcholinesterase (AChE), pancreatic lipase (PL), and neuraminidase (NA)) inhibitory activities. These bioassay results revealed that compounds 2 and 14 exerted noticeable NA inhibitory effects, with IC50 values of 31.28 and 73.64 µM, respectively. In addition, compound 3 exhibited a weak inhibitory effect against PL. Furthermore, these compounds showed the potential of inhibiting enzymes in silico docking analysis to demonstrate the interactions between compounds and proteins.


Assuntos
Antozoários , Neuraminidase , Animais , Lipase/metabolismo , Acetilcolinesterase/metabolismo , Aspergillus/química , Antozoários/metabolismo , Estrutura Molecular
5.
Mar Drugs ; 21(10)2023 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-37888468

RESUMO

Five new fusarin derivatives, steckfusarins A-E (1-5), and two known natural products (6, 7), were isolated and identified from the marine algicolous fungus Penicillium steckii SCSIO 41040. The new compounds, including absolute configurations, were determined by spectroscopic analyses and calculated electronic circular dichroism (ECD). All new compounds were evaluated for their antioxidant, antibacterial, antifungal, antiviral, cytotoxic, anti-inflammatory, antioxidant, cholesterol-lowering, acetyl cholinesterase (AChE) enzyme and 6-phosphofructo-2-kinase (PFKFB3) and phosphatidylinositol-3-kinase (PI3K) inhibitory activities. The biological evaluation results revealed that compound 1 exhibited radical scavenging activity against 2,2-diphenyl-1-picrylhydrazylhydrate (DPPH), with an IC50 value of 74.5 µg/mL. In addition, compound 1 also showed weak anti-inflammatory activity at a concentration of 20 µM.


Assuntos
Antioxidantes , Penicillium , Estrutura Molecular , Antioxidantes/farmacologia , Fungos/química , Penicillium/química , Dicroísmo Circular , Anti-Inflamatórios/farmacologia
6.
Nat Prod Res ; : 1-4, 2023 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-37850461

RESUMO

Twelve compounds, including eleven bisabolane-type sesquiterpenoids (1 - 11), and one bacillibactin (12) were identified from marine-derived fungus Aspergillus sydowii SCSIO 41041 isolated from Creseis acicula. The chemical structures were elucidated by the basis of spectroscopic evidences, including HRESIMS, NMR and optical rotation. Biologically, all compounds were evaluated for their acetyl cholin-esterase (AChE) enzyme, pancreatic lipase (PL) enzyme, neuraminidase (NA) and phosphodiesterase 4 (PDE4) inhibitory activities. Compound 12 displayed significant inhibitory activity against neuraminidase (NA) with an IC50 value of 24.0 µM, which was equivalent to the positive drug oseltamivir phosphate (IC50 value of 20.0 µM). And the NA inhibitory activity was confirmed by molecular docking analysis.

7.
Nat Prod Bioprospect ; 13(1): 41, 2023 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-37848577

RESUMO

Microbes well-adapted to the Arctic Ocean are promising for producing novel compounds, due to their fancy strategies for adaptation and being under-investigated. Two new phenazine alkaloids (1 and 2) and one new phenoxazine (3) were isolated from Nocardiopsis dassonvillei 502F, a strain originally isolated from Arctic deep-sea sediments. AntiSMASH analysis of the genome of Nocardiopsis dassonvillei 502F revealed the presence of 16 putative biosynthetic gene clusters (BGCs), including a phenazine BGC. Most of the isolated compounds were evaluated for their antibacterial, antiallergic, and cytotoxic activities. Among them, compounds 4 and 5 exhibited potent in vitro cytotoxic activities against osteosarcoma cell line 143B with IC50 values 0.16 and 20.0 µM, respectively. Besides, the results of antiallergic activities of compounds 6-8 exhibited inhibitory activities with IC50 values of 10.88 ± 3.05, 38.88 ± 3.29, and 2.44 ± 0.17 µg/mL, respectively (IC50 91.6 µM for the positive control loratadine).

8.
Mar Drugs ; 21(6)2023 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-37367651

RESUMO

Based on the marine natural products piperafizine B, XR334, and our previously reported compound 4m, fourteen novel 3,6-diunsaturated 2,5-diketopiperazine (2,5-DKP) derivatives (1, 2, 4-6, 8-16), together with two known ones (3 and 7), were designed and synthesized as anticancer agents against the A549 and Hela cell lines. The MTT assay results showed that the derivatives 6, 8-12, and 14 had moderate to good anticancer capacities, with IC50 values ranging from 0.7 to 8.9 µM. Among them, compound 11, with naphthalen-1-ylmethylene and 2-methoxybenzylidene functions at the 3 and 6 positions of 2,5-DKP ring, respectively, displayed good inhibitory activities toward both A549 (IC50 = 1.2 µM) and Hela (IC50 = 0.7 µM) cancer cells. It could also induce apoptosis and obviously block cell cycle progression in the G2/M phases in both cells at 1.0 µM. The electron-withdrawing functions might not be favorable for the derivatives with high anticancer activities. Additionally, compared to piperafizine B and XR334, these semi-N-alkylated derivatives have high liposolubilities (>1.0 mg mL-1). Compound 11 can be further developed, aiming at the discovery of a novel anticancer candidate.


Assuntos
Antineoplásicos , Humanos , Estrutura Molecular , Relação Estrutura-Atividade , Células HeLa , Proliferação de Células , Ensaios de Seleção de Medicamentos Antitumorais , Antineoplásicos/farmacologia , Desenho de Fármacos , Linhagem Celular Tumoral , Apoptose
9.
Phytochemistry ; 213: 113765, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37330031

RESUMO

Small cell lung cancer (SCLC) is a kind of high-grade neuroendocrine carcinoma, which is characterized by a higher proliferative rate, earlier metastasis and more poor outcomes compared to non-small cell lung cancer (NSCLC). Under the guidance of MS/MS based molecular networking, three undescribed pyridone alkaloids, namely, arthpyrones M-O (1-3), together with two known pyridone derivatives, arthpyrones C (4) and G (5), were isolated from a sponge-derived Arthrinium arundinis. Their structures were determined through extensive spectroscopic analysis, ECD calculations, and X-ray single-crystal diffraction. Arthpyrone M (1) possessed a novel cage structure bearing an ether bridge functionality rarely reported in this class of metabolites. All isolated compounds were evaluated for their cytotoxicities against five cancer cell lines. As a result, compounds 1-5 showed cytotoxicity against some or all of the five cancer cell lines with IC50 values ranging from 0.26 to 6.43 µM. Among them, arthpyrone O (3) not only exhibited potent efficacy against the proliferative activity of SCLC cells and induced apoptosis in vitro, but also significantly inhibited the growth of xenograft tumor based on SCLC cells in vivo, which indicated 4-hydroxy-2-pyridone alkaloids might been revised as privileged scaffolds in drug discovery.


Assuntos
Alcaloides , Antineoplásicos , Ascomicetos , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Espectrometria de Massas em Tandem , Neoplasias Pulmonares/tratamento farmacológico , Ascomicetos/química , Piridinas , Piridonas/química , Piridonas/farmacologia , Antineoplásicos/química , Alcaloides/química , Apoptose , Estrutura Molecular
10.
Sci Total Environ ; 886: 163920, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37156381

RESUMO

Biomass is a renewable and carbon-neutral resource with good features for producing biofuels, biochemicals, and biomaterials. Among the different technologies developed to date to convert biomass into such commodities, hydrothermal conversion (HC) is a very appealing and sustainable option, affording marketable gaseous (primarily containing H2, CO, CH4, and CO2), liquid (biofuels, aqueous phase carbohydrates, and inorganics), and solid products (energy-dense biofuels (up to 30 MJ/kg) with excellent functionality and strength). Given these prospects, this publication first-time puts together essential information on the HC of lignocellulosic and algal biomasses covering all the steps involved. Particularly, this work reports and comments on the most important properties (e.g., physiochemical and fuel properties) of all these products from a holistic and practical perspective. It also gathers vital information addressing selecting and using different downstream/upgrading processes to convert HC reaction products into marketable biofuels (HHV up to 46 MJ/kg), biochemicals (yield >90 %), and biomaterials (great functionality and surface area up to 3600 m2/g). As a result of this practical vision, this work not only comments on and summarizes the most important properties of these products but also analyzes and discusses present and future applications, establishing an invaluable link between product properties and market needs to push HC technologies transition from the laboratory to the industry. Such a practical and pioneering approach paves the way for the future development, commercialization and industrialization of HC technologies to develop holistic and zero-waste biorefinery processes.


Assuntos
Biocombustíveis , Carboidratos , Biomassa , Gases , Materiais Biocompatíveis , Lignina/química
11.
Polymers (Basel) ; 15(10)2023 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-37242874

RESUMO

High-performance chrome-free leather production is currently one of the most concerning needs to warrant the sustainable development of the leather industry due to the serious chrome pollution. Driven by these research challenges, this work explores using biobased polymeric dyes (BPDs) based on dialdehyde starch and reactive small-molecule dye (reactive red 180, RD-180) as novel dyeing agents for leather tanned using a chrome-free, biomass-derived aldehyde tanning agent (BAT). FTIR, 1H NMR, XPS, and UV-visible spectrometry analyses indicated that a Schiff base structure was generated between the aldehyde group of dialdehyde starch (DST) and the amino group of RD-180, resulting in the successful load of RD-180 on DST to produce BPD. The BPD could first penetrate the BAT-tanned leather efficiently and then be deposited on the leather matrix, thus exhibiting a high uptake ratio. Compared with the crust leathers prepared using a conventional anionic dye (CAD), dyeing, and RD-180 dyeing, the BPD-dyed crust leather not only had better coloring uniformity and fastness but it also showed a higher tensile strength, elongation at break, and fullness. These data suggest that BPD has the potential to be used as a novel sustainable polymeric dye for the high-performance dyeing of organically tanned chrome-free leather, which is paramount to ensuring and promoting the sustainable development of the leather industry.

12.
Molecules ; 28(5)2023 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-36903326

RESUMO

Ficus pandurata Hance (FPH) is a Chinese herbal medicine widely used for health care. This study was designed to investigate the alleviation efficacy of the low-polarity ingredients of FPH (FPHLP), prepared by supercritical CO2 fluid extraction technology, against CCl4-induced acute liver injury (ALI) in mice and uncover its underlying mechanism. The results showed that FPHLP had a good antioxidative effect determined by the DPPH free radical scavenging activity test and T-AOC assay. The in vivo study showed that FPHLP dose-dependently protected against liver damage via detection of ALT, AST, and LDH levels and changes in liver histopathology. The antioxidative stress properties of FPHLP suppressed ALI by increasing levels of GSH, Nrf2, HO-1, and Trx-1 and reducing levels of ROS and MDA and the expression of Keap1. FPHLP significantly reduced the level of Fe2+ and expression of TfR1, xCT/SLC7A11, and Bcl2, while increasing the expression of GPX4, FTH1, cleaved PARP, Bax, and cleaved caspase 3. The results demonstrated that FPHLP protected mouse liver from injury induced by CCl4 via suppression of apoptosis and ferroptosis. This study suggests that FPHLP can be used for liver damage protection in humans, which strongly supports its traditional use as a herbal medicine.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas , Ferroptose , Ficus , Animais , Camundongos , Antioxidantes/farmacologia , Apoptose , Dióxido de Carbono/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Ficus/metabolismo , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fígado , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo
13.
J Nat Prod ; 86(5): 1171-1178, 2023 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-36726314

RESUMO

Seven new tanzawaic acid derivatives, steckwaic acids E-K (1-7), and one new benzene derivate (8), together with seven known tanzawaic acid analogues (9-16) were isolated from the marine algicolous fungus Penicillium steckii SCSIO 41040. The structures and absolute configurations of these new compounds (1-8) were determined by spectroscopic analyses, X-ray diffraction, and comparison of ECD spectra to calculations. Compounds 2, 10, and 15 inhibited lipopolysaccharide (LPS)-induced nuclear factor kappa-B (NF-κB) with IC50 values of 10.4, 18.6, and 15.2 µM, respectively. Compound 2 could suppress the receptor activator of NF-κB ligand (RANKL)-induced osteoclast differentiation in bone marrow macrophage cells (BMMCs). To the best of our knowledge, this is the first report of osteoclastogenesis inhibitory activity for tanzawaic acid derivatives.


Assuntos
Osteogênese , Penicillium , Diferenciação Celular , Macrófagos , NF-kappa B , Osteoclastos , Penicillium/química , Ligante RANK/farmacologia , Policetídeos/química , Policetídeos/farmacologia
14.
Bioorg Chem ; 132: 106357, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36642018

RESUMO

Guided by Global Natural Products Social molecular networking, 14 new p-terphenyl derivatives, asperterphenyls A-N (1-14), together with 20 known p-terphenyl derivatives (15-34), were obtained from a sponge derived fungus Aspergillus sp. SCSIO41315. Among them, new compounds 2-8 and 15-17 were ten pairs of enantiomers. Comprehensive methods such as chiral-phase HPLC analysis, ECD calculations and X-ray diffraction analysis were applied to determine the absolute configurations. Asperterphenyls B (2) and C (3) represented the first reported natural p-terphenyl derivatives possessing a dicarboxylic acid system. Asperterphenyl A (1) displayed neuraminidase inhibitory activity with an IC50 value of 1.77 ± 0.53 µM and could efficiently inhibit infection of multiple strains of H1N1 with IC50 values from 0.67 ± 0.28 to 1.48 ± 0.60 µM through decreasing viral plaque formation in a dose-dependent manner, which suggested that asperterphenyl A (1) might be exploited as a potential antiviral compound in the pharmaceutical fields.


Assuntos
Vírus da Influenza A Subtipo H1N1 , Compostos de Terfenil , Neuraminidase , Fungos , Aspergillus , Cristalografia por Raios X , Compostos de Terfenil/farmacologia , Estrutura Molecular
15.
Phytochemistry ; 208: 113593, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36709018

RESUMO

Ochrathinols A and B ((±)-1 and (±)-2), two undescribed sulfur-containing racemates, and ochracids A and B (3 and 4), two unprecedented pyrrolizidine alkaloids, were isolated from an Antarctic soil-derived fungus Aspergillus ochraceopetaliformis SCSIO 05702. Their structures including absolute configurations were determined through extensive spectroscopic analysis, chiral-phase HPLC analysis, quantum ECD calculations, and X-ray single-crystal diffraction. Ochrathinols A and B are unprecedented sulfur natural products featuring a novel 3-methylhexahydro-2H-cyclopenta [b]thiophene core. Interestingly, ochrathinol A ((±)-1) outstandingly suppressed the release of LPS-induced IL-1ß, IL-6, and TNF-α inflammatory cytokines with concentration of 10 µM and alleviated the unbalanced NAD+/NADH ratio caused by LPS in RAW264.7 macrophages.


Assuntos
Citocinas , Lipopolissacarídeos , Lipopolissacarídeos/farmacologia , Fungos , Enxofre
16.
Nat Prod Res ; 37(20): 3512-3518, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35722895

RESUMO

A new furanone analog, (E)-2-(8,9-dihydroxy-6,8-dimethyldec-4-en-2-yl)-met-hylfuran-3(2H)-one (1), together with six known compounds, including two diterpenoids (2 and 3), one butyrolactone (4) and three isocoumarins (5-7), were isolated from a deep-sea fungus, Purpureocillium sp. SCSIO 06693. Among them, compound 1 existed as two tautomeric forms (1a and 1b) differing in configuration of the furan ring. The chemical structures were elucidated by the basis of spectroscopic evidences, including HRESIMS, NMR and optical rotation. Isolated compounds were evaluated for their cytotoxic, antiviral, antibacterial, antioxidant, acetyl cholinesterase (AChE) and pancreatic lipase (PL) enzyme inhibitory activities. Biological evaluation results revealed that compound 4 showed modest antioxidant activity against DPPH with IC50 value of 72.03 µM. In addition, compounds 1-4 exhibited PL enzyme inhibitory activities.

17.
Nat Prod Res ; 37(3): 389-396, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34498972

RESUMO

A new indole diketopiperazine alkaloid, named penilline D (1), together with five known indole alkaloid analogues (2-5, 11), two meroterpenoids (6 and 12), and four butenolide derivatives (7-10), were isolated from the Antarctic fungus Penicillium sp. SCSIO 05705. Extensive spectroscopic analysis and electronic circular dichroism (ECD) calculation were used to elucidate the structure of penilline D (1), including its absolute configuration. All isolated compounds (1-12) were evaluated for their cytotoxic, antibacterial and enzyme inhibitory activities against acetylcholinesterase (AChE) and pancreatic lipase (PL). Among them, compound 5 exhibited moderate in vitro cytotoxic activity against the 143B cell line with IC50 value of 12.64 ± 0.78 µM. Compound 6 showed strong inhibitory activity against AChE with IC50 value of 0.36 nM (IC50 18.7 nM for Tacrine), while compounds 6 and 11 showed weak PL enzyme inhibitory activity. Furthermore, an in silico molecular docking study was also performed between 6 and AChE.


Assuntos
Antineoplásicos , Penicillium , Policetídeos , Acetilcolinesterase , Dicroísmo Circular , Dicetopiperazinas , Alcaloides Indólicos , Simulação de Acoplamento Molecular , Estrutura Molecular , Penicillium/química , Policetídeos/química
18.
Nat Prod Res ; 37(17): 2871-2877, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36318871

RESUMO

The chemical investigation of the EtOAc extract from the solid rice medium cultured with a sponge-associated fungus Penicillium sp. SCSIO41033 led to the isolation of two quinolones including a new one, penicinolone (1), three xanthone derivatives (3-5), and four anthraquinones (6-9). Their structures were determined by comprehensive analysis of 1H and 13C NMR, COSY, HSQC, and HMBC spectroscopic, and HRESIMS mass spectrometric data. The bioactive assays revealed that compounds 1 and 2 showed no antimicrobial activities against five bacteria and eight fungi, and compounds 5, 8 and 9 exhibited inhibition against AChE with IC50 values of 45.9, 42.5 and 40.5 µg/mL. Molecular docking analysis was performed to explore the interactions between active molecules and AChE protein, which indicated that xanthone and anthraquinone derivatives had the potential for developing AChE inhibitors.

19.
Micromachines (Basel) ; 13(10)2022 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-36295934

RESUMO

The process parameters chosen for high-performance machining in the milling of a thin-walled workpiece are determined by a stability prediction model, which needs accurate modal parameters of the machining system. However, the in-process modal parameters are different from the offline modal parameters and are difficult to precisely obtain due to material removal. To address this problem, an accurate time-dependent autoregressive moving average with an exogenous input (TARMAX) method is proposed for the identification of the modal parameters in the milling of a thin-walled workpiece. In this process, a TARMAX model considering external force excitation is constructed to characterize the actual condition in the milling of a thin-walled workpiece. Then, recursive method and sliding window recursive method are used to identify TARMAX model parameters under time-varying cutting conditions. Subsequently, a three-degree of freedom (3-DOF) time-varying structure numerical model under theoretical milling forces and white-noise excitation is established, and the computational results show that the predicted natural frequencies using the proposed method are in close agreement with the simulated values. Finally, several experiments are designed and carried out to validate the effectiveness of the proposed method. The experimental results show that the predicted accuracy of the proposed method using actual cutting forces is 95.68%. Good agreement has been drawn in the numerical simulation and machining experiments. Our further research objectives will focus on the prediction of the damping ratios, modal stiffness, and modal mass.

20.
J Opt Soc Am A Opt Image Sci Vis ; 39(8): 1414-1419, 2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-36215585

RESUMO

The analytical formula of the probability density of a single orbital angular momentum (OAM) mode for pin-like optical vortex beams (POVBs) in turbulent atmosphere is derived. Its OAM spectrum in the receiving plane is obtained by the numerical calculation. For comparison, the OAM spectrum of commonly Gaussian vortex beams is showed, too. Those results show that POVBs show good performance on resisting the cross talk of the OAM mode induced by the turbulence in some cases, such as smaller radius of the receiving aperture, longer propagation distance, and stronger turbulence. Our finding has application in free-space optical communication based on the OAM mode.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...