Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 147
Filtrar
1.
BMC Ophthalmol ; 24(1): 206, 2024 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-38711059

RESUMEN

PURPOSE: The main objective is to quantify the lens nuclear opacity using spectral-domain optical coherence tomography (SD-OCT) and to evaluate its association with Lens Opacities Classification System III (LOCS-III) system, lens thickness (LT), and surgical parameters. The secondary objective is to assess the diagnostic model performance for hard nuclear cataract. METHODS: This study included 70 eyes of 57 adults with cataract, with 49 (70%) and 21 (30%) in training and validation cohort, respectively. Correlations of the average nuclear density (AND) /maximum nuclear density (MND) with LOCS-III scores, LT, and surgical parameters were analyzed. Univariate and multivariate logistic regression analysis, receiver operating characteristic curves and calibration curves were performed for the diagnostic of hard nuclear cataract. RESULTS: The pre-operative uncorrected distance visual acuity (UDVA), intraocular pressure (IOP), mean axial length (AL), and LT were 1.20 ± 0.47 log MAR, 15.50 ± 2.87 mmHg, 27.34 ± 3.77 mm and 4.32 ± 0.45 mm, respectively. The average nuclear opalescence (NO) and nuclear colour (NC) scores were 3.61 ± 0.94 and 3.50 ± 0.91 (ranging from 1.00 to 6.90), respectively. The average AND and MND were 137.94 ± 17.01 and 230.01 ± 8.91, respectively. NC and NO scores both significantly correlated with the AND (rNC = 0.733, p = 0.000; rNO = 0.755, p = 0.000) and MND (rNC = 0.643, p = 0.000; rNO = 0.634, p = 0.000). In the training cohort, the area under the curve (AUC) of the model was 0.769 (P < 0.001, 95%CI 0.620-0.919), which had a good degree of differentiation (Fig. 2a). The calibration curve showed good agreement between predicted and actual probability. CONCLUSION: The nuclear density measurement on SD-OCT images can serve as an objective and reliable indicator for quantifying nuclear density.


Asunto(s)
Catarata , Núcleo del Cristalino , Tomografía de Coherencia Óptica , Agudeza Visual , Humanos , Femenino , Masculino , Tomografía de Coherencia Óptica/métodos , Catarata/diagnóstico , Anciano , Persona de Mediana Edad , Núcleo del Cristalino/patología , Núcleo del Cristalino/diagnóstico por imagen , Agudeza Visual/fisiología , Curva ROC , Estudios Retrospectivos , Facoemulsificación , Anciano de 80 o más Años , Adulto , Cristalino/diagnóstico por imagen , Cristalino/patología
2.
J Nanobiotechnology ; 22(1): 272, 2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38773580

RESUMEN

BACKGROUND: Transdermal delivery of sparingly soluble drugs is challenging due to their low solubility and poor permeability. Deep eutectic solvent (DES)/or ionic liquid (IL)-mediated nanocarriers are attracting increasing attention. However, most of them require the addition of auxiliary materials (such as surfactants or organic solvents) to maintain the stability of formulations, which may cause skin irritation and potential toxicity. RESULTS: We fabricated an amphiphilic DES using natural oxymatrine and lauric acid and constructed a novel self-assembled reverse nanomicelle system (DES-RM) based on the features of this DES. Synthesized DESs showed the broad liquid window and significantly solubilized a series of sparingly soluble drugs, and quantitative structure-activity relationship (QSAR) models with good prediction ability were further built. The experimental and molecular dynamics simulation elucidated that the self-assembly of DES-RM was adjusted by noncovalent intermolecular forces. Choosing triamcinolone acetonide (TA) as a model drug, the skin penetration studies revealed that DES-RM significantly enhanced TA penetration and retention in comparison with their corresponding DES and oil. Furthermore, in vivo animal experiments demonstrated that TA@DES-RM exhibited good anti-psoriasis therapeutic efficacy as well as biocompatibility. CONCLUSIONS: The present study offers innovative insights into the optimal design of micellar nanodelivery system based on DES combining experiments and computational simulations and provides a promising strategy for developing efficient transdermal delivery systems for sparingly soluble drugs.


Asunto(s)
Administración Cutánea , Micelas , Absorción Cutánea , Solubilidad , Solventes , Animales , Solventes/química , Piel/metabolismo , Piel/efectos de los fármacos , Ratones , Sistemas de Liberación de Medicamentos/métodos , Nanopartículas/química , Relación Estructura-Actividad Cuantitativa , Masculino , Simulación de Dinámica Molecular , Portadores de Fármacos/química
3.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 46(2): 210-216, 2024 Apr.
Artículo en Chino | MEDLINE | ID: mdl-38686717

RESUMEN

Objective To construct a scientific and practical management model of the hospice and palliative care outpatient clinic and provide a reference for the operation and development of the outpatient clinic. Methods The basic framework of the whole process management model of hospice and palliative care outpatient clinic was determined preliminarily by literature analysis,qualitative interviews and experts group meetings.Two rounds of consultation were conducted among 18 experts in hospice and palliative care and medical-nursing combined outpatient service by the Delphi method. Results The questionnaire response rates of the two rounds of expert consultation were both 100% and the authority coefficients of the two rounds of expert consultation were 0.88 and 0.91,respectively.Finally,the whole process management model of hospice and palliative care outpatient clinic was constructed,which was composed of three first-level indicators including staff composition,work structure and effect evaluation,5 second-level indicators and 62 third-level indicators. Conclusion The constructed whole process management model is scientific,innovative and continuous,which can provide a reference for the operation and development of the hospice and palliative care outpatient clinic.


Asunto(s)
Instituciones de Atención Ambulatoria , Cuidados Paliativos al Final de la Vida , Cuidados Paliativos , Cuidados Paliativos al Final de la Vida/organización & administración , Instituciones de Atención Ambulatoria/organización & administración , Encuestas y Cuestionarios , Humanos
4.
ACS Sens ; 9(3): 1545-1554, 2024 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-38450702

RESUMEN

rRNAs are prevalent in living organisms. They are produced in nucleolus and mitochondria and play essential cellular functions. In addition to the primary biofunction in protein synthesis, rRNAs have been recognized as the emerging signaling molecule and drug target for studies on nucleolus morphology, mitochondrial autophagy, and tumor cell malignancy. Currently, only a few rRNA-selective probes have been developed, and most of them encounter the drawbacks of low water solubility, poor nuclear membrane permeability, short emission wavelength, low stability against photobleaching, and high cytotoxicity. These unfavorable properties of rRNA probes limit their potential applications. In the present study, we reported a new rRNA-selective and near-infrared fluorescent turn-on probe, 4MPS-TO, capable of tracking rRNA in live human cancer cells. The real-time monitoring performance in nucleolus morphology and mitochondrial autophagy is demonstrated in HeLa cells. The probe shows great application potential for being used as a rRNA-selective, sensitive, and photostable imaging tool in chemical biology study and drug screening.


Asunto(s)
Mitofagia , Neoplasias , Humanos , Células HeLa , Colorantes Fluorescentes/química , Imagen Óptica/métodos , Autofagia
5.
Chem Commun (Camb) ; 60(25): 3413-3416, 2024 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-38441256

RESUMEN

A photoredox-catalyzed unsymmetrical diamination of alkenes by using N-aminopyridinium salts and nitriles as the amination reagents has been developed. Various vicinal diamines were obtained in moderate to excellent yields under mild reaction conditions. Furthermore, this protocol could be applied in the late-stage modification of pharmaceuticals and natural products. Preliminary mechanistic studies suggested that this methodology may undergo a radical pathway followed by a Ritter-type reaction.

6.
Bioorg Med Chem ; 102: 117656, 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38422567

RESUMEN

Urease is the main virulence factor of infectious gastritis and gastric ulcers. Urease inhibitors are regarded as the first choice for the treatment of such diseases. Based on the triazolone/oxadiazolone skeleton, a urea-like fragment being able to specifically bind the urease activity pocket and prevent urea from hydrolysis, we designed and synthesized 45 triazolones/oxadiazolones as urease inhibitors. Eight compounds were proved to show excellent inhibitory activity against Helicobacter pylori urease, being more potency than the clinically used urease inhibitor acetohydroxamic acid. The most active inhibitor with IC50 value of 1.2 µM was over 20-fold higher potent than the positive control. Enzymatic kinetic assays showed that these novel inhibitors reversibly inhibited urease with a mixed competitive mechanism. Molecular dockings provided evidence for the observations in enzyme assays. Furthermore, these novel inhibitors were proved as drug-like compounds with very low cytotoxicity to mammalian cells and favorable water solubility. These results suggested that triazolone and oxadiazolone were promising scaffolds for the design and discovery of novel urease inhibitors, and were expected as good candidates for further drug development.


Asunto(s)
Helicobacter pylori , Úlcera Gástrica , Animales , Ureasa , Simulación del Acoplamiento Molecular , Urea , Inhibidores Enzimáticos/farmacología , Mamíferos/metabolismo
7.
J Appl Biomater Funct Mater ; 22: 22808000231222704, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38217423

RESUMEN

OBJECTIVES: Silk fiber is difficult to degrade in vivo, which limits its application in tissue engineering materials such as artificial nerves. Therefore, in this study aim to promote its degradation in vivo by chemical treating silk fibers in vitro. MATERIALS AND METHODS: Sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), scanning electron microscopy (SEM) observations, mechanical test, Fourier transform infrared spectroscopy (FT-IR) measurements were used to investigate the degradation effect of chemicals (hydrochloric acid, phosphoric acid, acetic acid, sodium hydroxide, calcium hydroxide, sodium bicarbonate, and calcium chloride) on silk fiber in vitro. Immunofluorescence staining and transcriptome analysis were used to investigate the effect of inflammatory factors on the degradation of chemically treated silk fiber in rats. RESULTS: (1) Silks were separated into finer fibers in each group. (2) FT-IR absorption peaks of amides I, II, and III overlap in each group. (3) Silk degradation degree in each group was higher than that in an untreated group. The calcium chloride-treated group was completely degraded. (4) Fibronectin, collagen I, collagen III, integrin α and CD68 were immunofluorescence positive in all vegetation section. (5) There were no significant differences in the expressions of collagen I, collagen III, and fibronectin in the vegetations formed on the 14th day of subcutaneous implantation, while integrin α, CD68, TNF-α, IL-1b, and IL-23 express at higher levels with IL-10 at lower levels. CONCLUSIONS: All chemicals could completely degrade silk; however, their degradation products were not the same. The chemicals change the mechanical properties of silk by separating it into finer fibers, which increase the contact surface area between the silk and tissue fluid, accelerating the degradation of monofilaments in vivo by promoting inflammation and macrophage activity through the increased and decreased expressions of pro- and anti-inflammatory factors, respectively.


Asunto(s)
Fibroínas , Seda , Ratas , Animales , Seda/química , Fibronectinas , Fibroínas/química , Espectroscopía Infrarroja por Transformada de Fourier , Cloruro de Calcio , Colágeno/química , Colágeno Tipo I , Integrinas
8.
Transl Res ; 266: 68-83, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37995969

RESUMEN

Podocyte damage is the major cause of glomerular injury and proteinuria in multiple chronic kidney diseases. Metadherin (MTDH) is involved in podocyte apoptosis and promotes renal tubular injury in mouse models of diabetic nephropathy and renal fibrosis; however, its role in podocyte injury and proteinuria needs further exploration. Here, we show that MTDH was induced in the glomerular podocytes of patients with proteinuric chronic kidney disease and correlated with proteinuria. Podocyte-specific knockout of MTDH in mice reversed proteinuria, attenuated podocyte injury, and prevented glomerulosclerosis after advanced oxidation protein products challenge or adriamycin injury. Furthermore, specific knockout of MTDH in podocytes repressed ß-catenin phosphorylation at the Ser675 site and inhibited its downstream target gene transcription. Mechanistically, on the one hand, MTDH increased cAMP and then activated protein kinase A (PKA) to induce ß-catenin phosphorylation at the Ser675 site, facilitating the nuclear translocation of MTDH and ß-catenin; on the other hand, MTDH induced the deaggregation of pyruvate kinase M2 (PKM2) tetramers and promoted PKM2 monomers to enter the nucleus. This cascade of events leads to the formation of the MTDH/PKM2/ß-catenin/CBP/TCF4 transcription complex, thus triggering TCF4-dependent gene transcription. Inhibition of PKA activity by H-89 or blockade of PKM2 deaggregation by TEPP-46 abolished this cascade of events and disrupted transcription complex formation. These results suggest that MTDH induces podocyte injury and proteinuria by assembling the ß-catenin-mediated transcription complex by regulating PKA and PKM2 function.


Asunto(s)
Nefropatías Diabéticas , Podocitos , Insuficiencia Renal Crónica , Humanos , Ratones , Animales , Podocitos/metabolismo , beta Catenina/genética , beta Catenina/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico , Factores de Transcripción/genética , Proteinuria/genética , Proteinuria/metabolismo , Nefropatías Diabéticas/metabolismo , Insuficiencia Renal Crónica/metabolismo , Proteínas de la Membrana , Proteínas de Unión al ARN/metabolismo
9.
Chem Commun (Camb) ; 60(5): 598-601, 2024 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-38099839

RESUMEN

A new Cp*Rh(III)-catalyzed regioselective cyclization reaction of aromatic amides with allenes is reported. The use of allenyl derivatives bearing a directing-group assistant as a reaction promoter was the key to the success of this protocol. In this catalytic system, N-(pivaloyloxy)benzamide substrates react with allenes via Rh-σ-alkenyl intermediates, while N-(pivaloyloxy) indol substrates react via Rh-π-allyl intermediates. These reactions were characterized by mild reaction conditions, a broad substrate scope, and high functional-group compatibility to yield several high-value isoquinolinone and pyrimido[1,6-a]indol-1(2H)-one skeleton-containing compounds. The synthetic applications and primary mechanisms were also investigated.

10.
Int J Pharm ; 648: 123624, 2023 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-37984619

RESUMEN

Androgenetic alopecia (AGA) is the primary hair loss with impairing patients' quality of life. Finasteride (FIN) is an SRD5A2 inhibitor for AGA treatment, but oral FIN causes systemic adverse effects. Topical FIN delivery is anticipated to overcome this problem. Ferulic acid (FA) is a natural phenolic acid with vascular remodeling and anti-inflammatory effects. Herein, an active pharmaceutical ingredient ionic liquid (API IL) based on choline and FA (CF-IL) is for the first time constructed to load FIN for fabricating FIN CF-IL. CF-IL aims to act as carriers and cargos and enhance hair follicle (HF) co-delivery of FA and FIN for synergistic anti-alopecia. Thermal and spectroscopic analysis combined with quantum chemistry calculations and molecular dynamics confirm the formation of CF-IL. The CF-IL simultaneously increases the solubility of FA (∼648-fold) and FIN (∼686-fold), enhances the permeation and retention of FIN and FA through the follicular pathway, and promotes cellular uptake. FIN CFIL regulates the abnormal mRNA expressions in dihydrotestosterone-irritated hDPCs, and promotes hair regrowth in AGA mice in a combined manner with FIN and FA. These findings suggest that FA-based API IL is a promising approach for percutaneously co-delivering FA and FIN to HF, providing an enhanced targeting treatment for AGA.


Asunto(s)
Finasterida , Líquidos Iónicos , Humanos , Ratones , Animales , Finasterida/efectos adversos , Preparaciones Farmacéuticas , Calidad de Vida , Alopecia/tratamiento farmacológico , Proteínas de la Membrana , 3-Oxo-5-alfa-Esteroide 4-Deshidrogenasa
11.
J Biol Chem ; 299(12): 105414, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37918806

RESUMEN

The proteins that coordinate the complex transcriptional networks of aging have not been completely documented. Protein 14-3-3zeta is an adaptor protein that coordinates signaling and transcription factor networks, but its function in aging is not fully understood. Here, we showed that the protein expression of 14-3-3zeta gradually increased during aging. High levels of 14-3-3zeta led to shortened lifespan and imbalance of intestinal immune homeostasis in Drosophila, but the decrease in 14-3-3zeta protein levels by RNAi was able to significantly promote the longevity and intestinal immune homeostasis of fruit flies. Importantly, we demonstrate that adult-onset administration of TIC10, a compound that reduces the aging-related AKT and extracellular signal-regulated kinase (ERK) signaling pathways, rescues the shortened lifespan of 14-3-3zeta-overexpressing flies. This finding suggests that 14-3-3zeta plays a critical role in regulating the aging process. Our study elucidates the role of 14-3-3zeta in natural aging and provides the rationale for subsequent 14-3-3zeta-based antiaging research.


Asunto(s)
Proteínas 14-3-3 , Envejecimiento , Proteínas de Drosophila , Drosophila melanogaster , Intestinos , Animales , Proteínas 14-3-3/genética , Proteínas 14-3-3/metabolismo , Envejecimiento/genética , Drosophila melanogaster/crecimiento & desarrollo , Drosophila melanogaster/inmunología , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Longevidad , Transducción de Señal , Intestinos/inmunología
12.
J Transl Med ; 21(1): 639, 2023 09 19.
Artículo en Inglés | MEDLINE | ID: mdl-37726857

RESUMEN

BACKGROUND: Progressive peritoneal fibrosis is a worldwide public health concern impacting patients undergoing peritoneal dialysis (PD), yet there is no effective treatment. Our previous study revealed that a novel compound, micheliolide (MCL) inhibited peritoneal fibrosis in mice. However, its mechanism remains unclear. Brahma-related gene 1 (BRG1) is a key contributor to organ fibrosis, but its potential function in PD-related peritoneal fibrosis and the relationship between MCL and BRG1 remain unknown. METHODS: The effects of MCL on BRG1-induced fibrotic responses and TGF-ß1-Smads pathway were examined in a mouse PD model and in vitro peritoneal mesothelial cells. To investigate the targeting mechanism of MCL on BRG1, coimmunoprecipitation, MCL-biotin pulldown, molecular docking and cellular thermal shift assay were performed. RESULTS: BRG1 was markedly elevated in a mouse PD model and in peritoneal mesothelial cells cultured in TGF-ß1 or PD fluid condition. BRG1 overexpression in vitro augmented fibrotic responses and promoted TGF-ß1-increased-phosphorylation of Smad2 and Smad3. Meanwhile, knockdown of BRG1 diminished TGF-ß1-induced fibrotic responses and blocked TGF-ß1-Smad2/3 pathway. MCL ameliorated BRG1 overexpression-induced peritoneal fibrosis and impeded TGF-ß1-Smad2/3 signaling pathway both in a mouse PD model and in vitro. Mechanically, MCL impeded BRG1 from recognizing and attaching to histone H3 lysine 14 acetylation by binding to the asparagine (N1540) of BRG1, in thus restraining fibrotic responses and TGF-ß1-Smad2/3 signaling pathway. After the mutation of N1540 to alanine (N1540A), MCL was unable to bind to BRG1 and thus, unsuccessful in suppressing BRG1-induced fibrotic responses and TGF-ß1-Smad2/3 signaling pathway. CONCLUSION: Our research indicates that BRG1 may be a crucial mediator in peritoneal fibrosis and MCL targeting N1540 residue of BRG1 may be a novel therapeutic strategy to combat PD-related peritoneal fibrosis.


Asunto(s)
Diálisis Peritoneal , Fibrosis Peritoneal , Animales , Ratones , Modelos Animales de Enfermedad , Simulación del Acoplamiento Molecular , Diálisis Peritoneal/efectos adversos , Fibrosis Peritoneal/tratamiento farmacológico , Factor de Crecimiento Transformador beta1
13.
Org Lett ; 25(28): 5179-5184, 2023 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-37415264

RESUMEN

Rh (III)-catalyzed dienylation and cyclopropylation of 1,2,3-benzotriazinones with alkylidenecyclopropanes (ACPs) has been achieved. Different from the previous reports of 1,2,3-benzotriazinones, the triazinone ring remained intact in this C-H bond functionlization reaction. Also, the denitrogenative cyclopropylation could also be realized by changing the reaction temperature. This protocol is featured with high E selectivity, wide substrate scope, and divergent structures of products.

14.
Org Lett ; 25(23): 4286-4291, 2023 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-37265108

RESUMEN

Two categories of tetrasubstituted phenols were prepared via the cycloaddition reaction of vinyl sulfoxonnium ylides with cyclopropenones in a switchable manner. Copper carbenoid was proposed as the active intermediate in the process of 2,3,4,5-tetrasubstituted phenols formation, while 2,3,5,6-tetrasubstituted phenols were generated via the direct [3 + 3] annulation of vinyl sulfoxonnium ylides with cyclopropenones under metal-free conditions. Further synthetic applications were also demonstrated.


Asunto(s)
Cobre , Metales , Catálisis , Reacción de Cicloadición
15.
Chem Biol Interact ; 382: 110589, 2023 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-37268199

RESUMEN

Peritoneal fibrosis (PF) is the main cause of peritoneal ultrafiltration failure in patients undergoing long-term peritoneal dialysis (PD). Epithelial-mesenchymal transition (EMT) is the key pathogenesis of PF. However, currently, no specific treatments are available to suppress PF. N-methylpiperazine-diepoxyovatodiolide (NMPDOva) is a newly synthesized compound that involves a chemical modification of ovatodiolide. In this study, we aimed to explore the antifibrotic effects of NMPDOva in PD-related PF and underlying mechanisms. A mouse model of PD-related PF was established via daily intraperitoneal injection of 4.25% glucose PD fluid. In vitro studies were performed using the transforming growth factor-beta1 (TGF-ß1)-stimulated HMrSV5 cell line. Pathological changes were observed, and fibrotic markers were significantly elevated in the peritoneal membrane in mice model of PD-related PF. However, NMPDOva treatment significantly alleviated PD-related PF by decreasing the extracellular matrix accumulation. NMPDOva treatment decreased the expression of fibronectin, collagen Ⅰ, and alpha-smooth muscle actin (α-SMA) in mice with PD-related PF. Moreover, NMPDOva could alleviate TGF-ß1-induced EMT in HMrSV5 cells, inhibited phosphorylation and nuclear translocation of Smad2/3, and increased the expression of Smad7. Meanwhile, NMPDOva inhibited phosphorylation of JAK2 and STAT3. Collectively, these results indicated that NMPDOva prevents PD-related PF by inhibiting the TGF-ß1/Smad and JAK/STAT signaling pathway. Therefore, because of these antifibrotic effects, NMPDOva may be a promising therapeutic agent for PD-related PF.


Asunto(s)
Fibrosis Peritoneal , Ratones , Animales , Fibrosis Peritoneal/tratamiento farmacológico , Fibrosis Peritoneal/etiología , Fibrosis Peritoneal/patología , Factor de Crecimiento Transformador beta1/metabolismo , Factor de Crecimiento Transformador beta/metabolismo , Transducción de Señal , Peritoneo/metabolismo , Peritoneo/patología , Transición Epitelial-Mesenquimal , Fibrosis
16.
Org Biomol Chem ; 21(26): 5356-5360, 2023 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-37337771

RESUMEN

A divergent fluorination of alkylidenecyclopropanes (ACPs) and alkylidenecyclobutanes (ACBs) with selectfluor has been achieved. Four different types of products including fluorohydrins, fluoroethers, fluoroesters and fluoroketones could be prepared in moderate to excellent yields. In particular, the cyclopropanes and cyclobutanes were not destroyed during the transformations which involved a radical pathway. The applicability of this method was demonstrated by various transformations of the products.

17.
Opt Express ; 31(6): 9827-9840, 2023 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-37157545

RESUMEN

Photonic microwave generation based on period-one (P1) dynamics of an optically pumped spin-polarized vertical-cavity surface-emitting laser (spin-VCSEL) is investigated numerically. Here, the frequency tunability of the photonic microwave generated from a free-running spin-VCSEL is demonstrated. The results show that the frequency of the photonic microwave signals can be widely tuned (from several gigahertz to hundreds of gigahertz) by changing the birefringence. Furthermore, the frequency of the photonic microwave can be modestly adjusted by introducing an axial magnetic field, although it degrades the microwave linewidth in the edge of Hopf bifurcation. To improve the quality of the photonic microwave, an optical feedback technique is employed in a spin-VCSEL. Under the scenario of single-loop feedback, the microwave linewidth is decreased by enhancing the feedback strength and/or delay time, whereas the phase noise oscillation increases with the increase of the feedback delay time. By adding the dual-loop feedback, the Vernier effect can effectively suppress the side peaks around the central frequency of P1, and simultaneously supports P1 linewidth narrowing and phase noise minimization at long times.

18.
Opt Express ; 31(10): 16178-16191, 2023 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-37157702

RESUMEN

We report on the manipulation of extreme events (EEs) in a slave spin-polarized vertical-cavity surface-emitting laser (spin-VCSEL) subject to chaotic optical injection from a master spin-VCSEL. The master laser is free-running but yielding a chaotic regime with obvious EEs, while the slave laser originally (i.e., without external injection) operates in either continuous-wave (CW), period-one (P1), period-two (P2), or a chaotic state. We systematically investigate the influence of injection parameters, i.e., injection strength and frequency detuning, on the characteristics of EEs. We find that injection parameters can regularly trigger, enhance, or suppress the relative number of EEs in the slave spin-VCSEL, where the large ranges of enhanced vectorial EEs and average intensity of both vectorial and scalar EEs can be achieved with suitable parameter conditions. Moreover, with the help of two-dimensional correlation maps, we confirm that the probability of occurrence of EEs in the slave spin-VCSEL is associated with the injection locking regions, outside which enhanced relative number of EEs regions can be obtained and expanded with augmenting the complexity of the initial dynamic state of the slave spin-VCSEL.

19.
Cells ; 12(9)2023 04 25.
Artículo en Inglés | MEDLINE | ID: mdl-37174650

RESUMEN

Gut microbiota dysbiosis with increased pathogenic bacteria and decreased beneficial bacteria is associated with colorectal cancer (CRC) development. This study examined the effect of a newly developed probiotic formula in modulating CRC-related bacteria. We developed a probiotic formula containing three bifidobacteria (B. adolescentis, B. longum, and B. bifidum) based on the identification of bacterial species that showed significant correlations with CRC-related bacteria including Fusobacterium nucleatum (Fn), Lachnoclostridium sp. m3, Clostridium hathewayi (Ch), and Bacteroides clarus (Bc). We co-cultured Fn with each bifidobacterium or the combined formula and examined the growth of Fn by qPCR. The three individual bifidobacteria significantly inhibited the growth of Fn compared to the control treatment (24~65% inhibition; all p < 0.001). The combination of the three bifidobacteria showed a greater inhibitory effect on Fn growth (70% inhibition) than the individual bifidobacteria (all p < 0.05). We further examined the effect of the probiotic formula in a pilot study of 72 subjects (40 on probiotics; 32 with no intervention) for 4 weeks and followed them up for 12 weeks. The relative fecal abundances of the bifidobacteria in the formula and the CRC-related markers (Fn, m3, Ch, and Bc) were quantitated by qPCR before and after the intervention, and the combined CRC risk score (4Bac; Fn, m3, Ch, and Bc) was evaluated. Subjects with probiotics intervention showed significantly increased abundances of the bifidobacteria from week 2 to week 5 compared to baseline (p < 0.05), and the abundances dropped to baseline levels after the cessation of the intervention. There were significant decreases in the levels of CRC-related markers (Fn and m3) and the CRC risk score (4Bac) from week 2 to week 12 compared to baseline levels (p < 0.05) in the intervention group but not in the control group. A novel probiotic formula containing B. adolescentis, B. longum, and B. bifidum was effective in inhibiting the growth of F. nucleatum in vitro and improving the gut microbial environment against CRC development.


Asunto(s)
Neoplasias Colorrectales , Probióticos , Humanos , Proyectos Piloto , Probióticos/uso terapéutico , Heces/microbiología , Bifidobacterium/fisiología
20.
Environ Sci Pollut Res Int ; 30(24): 65712-65727, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37093372

RESUMEN

In recent years, metal-organic frameworks (MOFs) have been employed in numerous applications for adsorption. Researchers synthesize new MOFs by various methods, including the introduction of functional groups. In this study, three different aluminum-based MOFs (with non-functionalized, amino-functionalized, nitro-functionalized) were produced by hydrothermal synthesis and used for investigating typical endocrine disrupting chemicals (EDCs), namely for bisphenol A (BPA) adsorption. We used several methods to characterize the MOFs and conducted batch adsorption experiments to investigate their adsorption properties, and explore the influence of different functional groups on adsorption materials. The specific surface area of Al-MOF-NH2 is 6 times larger than that of Al-MOF according to the N2 adsorption and desorption isotherms of the material, that is, the BET of Al-MOF, Al-MOF-NH2, and Al-MOF-NO2 were 109.68, 644.03, and 146.60 m2/g. Note that although the same synthesis method is used, pore size is greatly changed because of the different functional groups. Al-MOF and Al-MOF-NO2 have more mesopores, and Al-MOF-NH2 is mainly microporous. The BPA adsorption capacities of Al-MOF, Al-MOF-NH2, and Al-MOF-NO2 were 46.43, 227.78, and 155.84 mg/L. The outcomes can also be explained by the improved adsorption performance from the addition of amino functional groups. In this research, the adsorption isotherms and adsorption kinetics of the three Al-MOFs for BPA were also investigated to explain the different adsorption properties of various functional groups. The results show that the amino-functionalized materials have remarkable characterization morphologies, uniform particle distributions, appropriate particle sizes, excellent specific surface areas, and superior adsorption effects.


Asunto(s)
Estructuras Metalorgánicas , Estructuras Metalorgánicas/química , Aluminio/química , Adsorción , Dióxido de Nitrógeno , Agua
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA