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1.
Proc Natl Acad Sci U S A ; 119(46): e2208804119, 2022 11 16.
Artículo en Inglés | MEDLINE | ID: mdl-36343253

RESUMEN

Neuronal PER-ARNT-SIM (PAS) domain protein 4 (NPAS4) is a protective transcriptional regulator whose dysfunction has been linked to a variety of neuropsychiatric and metabolic diseases. As a member of the basic helix-loop-helix PER-ARNT-SIM (bHLH-PAS) transcription factor family, NPAS4 is distinguished by an ability to form functional heterodimers with aryl hydrocarbon receptor nuclear translocator (ARNT) and ARNT2, both of which are also bHLH-PAS family members. Here, we describe the quaternary architectures of NPAS4-ARNT and NPAS4-ARNT2 heterodimers in complexes involving DNA response elements. Our crystallographic studies reveal a uniquely interconnected domain conformation for the NPAS4 protein itself, as well as its differentially configured heterodimeric arrangements with both ARNT and ARNT2. Notably, the PAS-A domains of ARNT and ARNT2 exhibit variable conformations within these two heterodimers. The ARNT PAS-A domain also forms a set of interfaces with the PAS-A and PAS-B domains of NPAS4, different from those previously noted in ARNT heterodimers formed with other class I bHLH-PAS family proteins. Our structural observations together with biochemical and cell-based interrogations of these NPAS4 heterodimers provide molecular glimpses of the NPAS4 protein architecture and extend the known repertoire of heterodimerization patterns within the bHLH-PAS family. The PAS-B domains of NPAS4, ARNT, and ARNT2 all contain ligand-accessible pockets with appropriate volumes required for small-molecule binding. Given NPAS4's linkage to human diseases, the direct visualization of these PAS domains and the further understanding of their relative positioning and interconnections within the NPAS4-ARNT and NPAS4-ARNT2 heterodimers may provide a road map for therapeutic discovery targeting these complexes.


Asunto(s)
Translocador Nuclear del Receptor de Aril Hidrocarburo , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico , Humanos , Translocador Nuclear del Receptor de Aril Hidrocarburo/metabolismo , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , ADN/metabolismo , Regulación de la Expresión Génica , Elementos de Respuesta , Multimerización de Proteína
2.
BMC Genomics ; 25(1): 254, 2024 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-38448814

RESUMEN

BACKGROUND: Neddylation, an important post-translational modification (PTM) of proteins, plays a crucial role in follicular development. MLN4924 is a small-molecule inhibitor of the neddylation-activating enzyme (NAE) that regulates various biological processes. However, the regulatory mechanisms of neddylation in rabbit ovarian cells have not been emphasized. Here, the transcriptome and metabolome profiles in granulosa cells (GCs) treated with MLN4924 were utilized to identify differentially expressed genes, followed by pathway analysis to precisely define the altered metabolisms. RESULTS: The results showed that 563 upregulated and 910 downregulated differentially expressed genes (DEGs) were mainly enriched in pathways related to cancer, cell cycle, PI3K-AKT, progesterone-mediated oocyte maturation, and PPAR signaling pathway. Furthermore, we characterized that MLN4924 inhibits PPAR-mediated lipid metabolism, and disrupts the cell cycle by promoting the apoptosis and proliferation of GCs. Importantly, we found the reduction of several metabolites in the MLN4924 treated GCs, including glycerophosphocholine, arachidic acid, and palmitic acid, which was consistent with the deregulation of PPAR signaling pathways. Furthermore, the increased metabolites included 6-Deoxy-6-sulfo-D-glucono-1,5-lactone and N-Acetyl-D-glucosaminyldiphosphodolichol. Combined with transcriptome data analyses, we identified genes that strongly correlate with metabolic dysregulation, particularly those related to glucose and lipid metabolism. Therefore, neddylation inhibition may disrupt the energy metabolism of GCs. CONCLUSIONS: These results provide a foundation for in-depth research into the role and molecular mechanism of neddylation in ovary development.


Asunto(s)
Ciclopentanos , Receptores Activados del Proliferador del Peroxisoma , Fosfatidilinositol 3-Quinasas , Pirimidinas , Femenino , Animales , Conejos , Células de la Granulosa , Metabolismo de los Lípidos
3.
BMC Geriatr ; 24(1): 408, 2024 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-38714912

RESUMEN

BACKGROUND: Abnormal amyloid ß (Aß) deposits in the brain are a hallmark of Alzheimer's disease (AD). Insufficient sleep duration and poor sleep quality are risk factors for developing AD. Sleep may play a role in Aß regulation, but the magnitude of the relationship between sleep and Aß deposition remains unclear. This systematic review examines the relationship between sleep (i.e., duration and efficiency) with Aß deposition in later-life adults. METHODS: A search of PubMed, CINAHL, Embase, and PsycINFO generated 5,005 published articles. Fifteen studies met the inclusion criteria for qualitative syntheses; thirteen studies for quantitative syntheses related to sleep duration and Aß; and nine studies for quantitative syntheses related to sleep efficiency and Aß. RESULTS: Mean ages of the samples ranged from 63 to 76 years. Studies measured Aß using cerebrospinal fluid, serum, and positron emission tomography scans with two tracers: Carbone 11-labeled Pittsburgh compound B or fluorine 18-labeled. Sleep duration was measured subjectively using interviews or questionnaires, or objectively using polysomnography or actigraphy. Study analyses accounted for demographic and lifestyle factors. Based on 13 eligible articles, our synthesis demonstrated that the average association between sleep duration and Aß was not statistically significant (Fisher's Z = -0.055, 95% CI = -0.117 ~ 0.008). We found that longer self-report sleep duration is associated with lower Aß (Fisher's Z = -0.062, 95% CI = -0.119 ~ -0.005), whereas the objectively measured sleep duration was not associated with Aß (Fisher's Z = 0.002, 95% CI = -0.108 ~ 0.113). Based on 9 eligible articles for sleep efficiency, our synthesis also demonstrated that the average association between sleep efficiency and Aß was not statistically significant (Fisher's Z = 0.048, 95% CI = -0.066 ~ 0.161). CONCLUSION: The findings from this review suggest that shorter self-reported sleep duration is associated with higher Aß levels. Given the heterogeneous nature of the sleep measures and outcomes, it is still difficult to determine the exact relationship between sleep and Aß. Future studies with larger sample sizes should focus on comprehensive sleep characteristics and use longitudinal designs to better understand the relationship between sleep and AD.


Asunto(s)
Péptidos beta-Amiloides , Sueño , Humanos , Péptidos beta-Amiloides/metabolismo , Sueño/fisiología , Anciano , Calidad del Sueño , Factores de Tiempo , Cognición/fisiología , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/diagnóstico , Persona de Mediana Edad , Duración del Sueño
4.
Amino Acids ; 55(1): 101-112, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36333524

RESUMEN

Infections induced by fungi, especially the drug-resistant fungi, are difficult clinical problems. Conventional antifungal treatment is effective but due to resistance, treatment failure, and treatment-related toxicity, there is a need for new antifungal drugs. In this study, SA-2 (YYRRLLRVLRRRW) was derived from Cystatin-SA, a saliva protein with a molecular weight of 14 kDa. Meanwhile, the structure-activity of SA-2 and its mutants was also studied. We detected the antimicrobial activity and cytotoxicity of SA-2 and found that SA-2 had a low cytotoxicity toward mammalian cells but a good inhibitory effect on Candida albicans (C. albicans) and Cryptococcus neoformans (C. neoformans), with MIC values of 16-64 µg/mL and 8-32 µg/mL, respectively. Interestingly, SA-2 effectively killed fluconazole-resistant C. neoformans and C. albicans within 12 h. This antifungal activity against fluconazole-resistant fungi was comparable to that of amphotericin B. In addition, the C. neoformans-infected mice model was established to evaluate the anti-infective activity of SA-2 in vivo. Results showed that SA-2 significantly reduced the counts of fungi in lung and brain tissues to protect fluconazole-resistant C. neoformans-infected mice from death without changing mice body weights. Moreover, the dramatically increased pro-inflammatory cytokines TNF-α, IL-6 and IL-1ß induced by intranasal infection of C. neoformans could be obviously declined due to the treatment of SA-2, which may be attributed to the elimination of C. neoformans in time in the infected tissue. For the mode of actions underlying SA-2 against C. neoformans, we found that the cationic peptide SA-2 could adhere to the negatively charged fungal cell membrane to increase the surface potential of C. neoformans in a dose-dependent manner, and finally disrupted the integrity of fungal cell membrane, reflecting as a 60% positive rate of propidium iodide uptake of C. neoformans cells after SA-2 (4 × MIC) treatment. Our study indicated that SA-2 has the potential to develop as a new therapeutic agent against infection induced by drug-resistant fungi.


Asunto(s)
Cryptococcus neoformans , Cistatinas , Animales , Ratones , Antifúngicos/farmacología , Fluconazol/farmacología , Pruebas de Sensibilidad Microbiana , Candida albicans , Cistatinas/farmacología , Mamíferos
5.
J Sleep Res ; : e14090, 2023 Nov 08.
Artículo en Inglés | MEDLINE | ID: mdl-37940373

RESUMEN

Hippocampal atrophy is a prominent neurodegenerative feature of Alzheimer's disease and related dementias. Alterations in circadian rhythms can exacerbate cognitive aging and neurodegeneration. This study aimed to examine how dim light melatonin onset and melatonin levels are associated with hippocampal volume in cognitively healthy individuals. We studied data from 52 later-life adults (mean age ± SD = 70.0 ± 6.3 years). T1-weighted anatomical images from 3.0 T magnetic resonance imaging data were collected and processed using the BRAINSTools toolbox. Dim light melatonin onset was used to assess circadian timing. The area under the curve was calculated to quantify melatonin concentration levels 6 hr before bedtime, and 14-day wrist actigraphy data were used to assess habitual bedtime. Multiple linear regression modelling with hippocampal volume as the dependent variable was used to analyse the data adjusting for age and sex. The average dim light melatonin onset was 19:45 hours (SD = 84 min), and area under the curve of melatonin levels 6 hr before habitual bedtime was 38.4 pg ml-1 × hr (SD = 29.3). We found that later dim light melatonin onset time (b = 0.16, p = 0.005) and greater area under the curve of melatonin levels 6 hr before habitual bedtime (b = 0.05, p = 0.046) were associated with greater adjusted hippocampal volume. The time between dim light melatonin onset and the midpoint of sleep timing was not associated with hippocampal volume. The findings suggest that earlier circadian timing (dim light melatonin onset) and reduced melatonin may be associated with reduced hippocampal volume in older adults. Future research will help researchers utilize circadian rhythm information to delay brain aging.

6.
Aquac Nutr ; 2023: 1232518, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37780581

RESUMEN

In this study, we screened the expression stability of six reference genes (18S rRNA, ß-actin, GAPDH, EF1a, B2M, and HPRT1) in hybrid yellow catfish (n = 6), considering the SBM levels, sampling time points, and different tissues. Four different statistical programs, BestKeeper, NormFinder, Genorm, and Delta Ct, combined with a method that comprehensively considered all results, were used to evaluate the expression stability of these reference genes systematically. The results showed that SBM levels significantly impacted the expression stability of most of the reference genes studied and that this impact was time-, dose-, and tissue-dependent. The expression stability of these six reference genes varied depending on tissue, sampling time point, and SBM dosage. Additionally, more variations were found among different tissues than among different SBM levels or sampling time points. Due to its high expression, 18S rRNA was excluded from the list of candidate reference genes. ß-actin and GAPDH in the liver and ß-actin, HPRT1 and EF1a in the intestine were the most stable reference genes when SBM levels were considered. HPRT1, and EF1a in tissues sampled at 2 W and EF1a and ß-actin in tissues sampled at 4 and 6 W were proposed as two stable reference genes when different tissues were considered. When the sampling time points were considered, ß-actin, EF1a, and HPRT1 were the top three stable reference genes in the intestine. In contrast, ß-actin and B2M are the most stable reference genes in the liver. In summary, ß-actin, EF1a, and HPRT1 were the more stable reference genes in this study. The stability of reference genes depends on the tissues, sampling time points, and SBM diet levels in hybrid yellow catfish. Therefore, attention should be paid to these factors before selecting suitable reference genes for normalizing the target genes.

7.
J Sci Food Agric ; 102(8): 3405-3415, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-34825372

RESUMEN

BACKGROUND: Few studies to date have evaluated the use of Lactobacillus and Bifidobacterium in edible fungus fermentation. To obtain a fermented Lentinus edodes liquid product with good taste and effects, a strain with good fermentation performance from nine strains tested was selected, and the physicochemical properties and antioxidant capacity of the resulting product were evaluated. RESULTS: Lactobacillus fermentum 21828 exhibited adhesion, tolerance to low pH and bile salts, and good fermentation performance. The number of viable bacteria was 1.05 × 108 CFU mL-1 , and the extraction rate of crude polysaccharide from L. edodes was 2.79% after fermentation. The effects of fermentation on the contents and composition of nutrients in L. edodes liquid were marked, with changes in total soluble protein, total soluble sugar, total acid, and total phenol levels. The 2,2-diphenyl-1-picrylhydrazyl radical-scavenging rate in the fermentation liquid was 93.01%, which was significantly higher than that in non-fermented liquid (80.33%). Furthermore, analysis of volatile and 5'-nucleotide contents showed that fermentation altered the flavor of the product, whereas sensory evaluation showed that the fermented product was preferred. CONCLUSION: Our study demonstrated that the fermented L. edodes liquid exhibited better nutritional and functional properties, as well as sensory characteristics, compared with unfermented liquid. © 2021 Society of Chemical Industry.


Asunto(s)
Limosilactobacillus fermentum , Hongos Shiitake , Antioxidantes/química , Fermentación , Lactobacillus/metabolismo , Limosilactobacillus fermentum/metabolismo , Hongos Shiitake/metabolismo
8.
Angew Chem Int Ed Engl ; 59(3): 1340-1345, 2020 01 13.
Artículo en Inglés | MEDLINE | ID: mdl-31502358

RESUMEN

Chiral sulfones are of great importance in medicinal chemistry and chemical synthesis. Efficient methods for preparing enantiomerically enriched sulfone-containing molecules can therefore be of significant value; such methods, however, are uncommon. Herein, we report the first general palladium-catalyzed sulfonylation of vinyl cyclic carbonates with sodium sulfinates. A series of enantiomerically enriched tertiary allylic sulfones were synthesized in good yields with excellent enantiomeric ratios. Both aliphatic- and aryl-substituted vinyl cyclic carbonates are suitable reactants with excellent results. This reaction features broad substrates scope, readily available starting materials, excellent regio- and enantioselectivity, and synthesis of sulfone-bearing quaternary carbon stereocenters. Through the sulfonylation of geranyl derived cyclic carbonate 1 h, we achieve the formal total synthesis of (+)-agelasidine A.

9.
Nanotechnology ; 30(13): 134001, 2019 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-30625445

RESUMEN

A large family of two-dimensional (2D) transition metal carbides, MXene, has demonstrated potential applications for electrochemical energy storage. 2D MXene sheets may buffer large volume changes and form a 3D conductive network to facilitate the electronic transfer of working electrodes. However, multilayer Ti3C2T x material could only deliver a moderate capacity in sodium ion battery cells, below the requirement of commercial applications. Herein, we decorated multilayer MXene (Ti3C2T x ) with Sb nanoparticles (NPs) via a facile solution-phase method, in which Sb NPs with a diameter of about 5-10 nm are absorbed on the surface of MXene layers by the electrostatic attraction action. The hybrid material Ti3C2T x @Sb-0.5 delivers a higher reversible capacity of 200 mA h g-1 at 0.1 A g-1 than that of pure Ti3C2T x (90 mA h g-1), and shows a much better capacity retention of nearly 98% after 500 cycles compared with Sb NPs. Also, it achieves superior rate performance (remaining a capacity of 127 mA h g-1 at 2 A g-1) and excellent long-term stability (a capacity retention of almost 92.3% after 8000 cycles). These results indicate that Ti3C2T x @Sb-0.5 possess a potential for high-performance sodium ion batteries anodes.

10.
Chemistry ; 23(21): 5148-5153, 2017 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-28244150

RESUMEN

Ag2 Mo2 O7 micro-rods are prepared by one-step hydrothermal method and their lithium electrochemical properties, as the anode for lithium-ion batteries, are comprehensively studied in terms of galvanostatic charge-discharge cycling, cyclic voltammetry, and rate performance measurements. The electrode delivers a high reversible capacity of 825 mAh g-1 at a current density of 100 mA g-1 and a superior rate capability with a discharge capacity of 263 mAh g-1 under the high current density of 2 Ag-1 . The structural transition and phase evolution of Ag2 Mo2 O7 were investigated by using ex situ XRD and TEM. The Ag2 Mo2 O7 electrode is likely to be decomposed into amorphous molybdenum, Li2 O, and metallic silver based on the conversion reaction. Silver nanoparticles are not involved in the subsequent electrochemical cycles to form a homogeneous conducting network. Such in situ decomposition behavior provides an insight into the mechanism of the electrochemical reaction for the anode materials and would contribute to the design of new electrode materials in future.

11.
Chemistry ; 22(21): 7248-54, 2016 05 17.
Artículo en Inglés | MEDLINE | ID: mdl-27061105

RESUMEN

Silver molybdate, Ag2 Mo2 O7 , has been prepared by a conventional solid-state reaction. Its electrochemical properties as an anode material for sodium-ion batteries (SIBs) have been comprehensively examined by means of galvanostatic charge-discharge cycling, cyclic voltammetry, and rate performance measurements. At operating voltages between 3.0 and 0.01 V, the electrode delivered a reversible capacity of nearly 190 mA h g(-1) at a current density of 20 mA g(-1) after 70 cycles. Ag2 Mo2 O7 also demonstrated a good rate capability and long-term cycle stability, the capacity reaching almost 100 mA h g(-1) at a current density of 500 mA g(-1) , with a capacity retention of 55 % over 1000 cycles. Moreover, the sodium storage process of Ag2 Mo2 O7 has been investigated by means of ex situ XRD, Raman spectroscopy, and HRTEM. Interestingly, the anode decomposes into Ag metal and Na2 MoO4 during the initial discharge process, and then Na(+) ions are considered to be inserted into/extracted from the Na2 MoO4 lattice in the subsequent cycles governed by an intercalation/deintercalation mechanism. Ex situ HRTEM images revealed that Ag metal not only remains unchanged during the sodiation/desodiation processes, but is well dispersed throughout the amorphous matrix, thereby greatly improving the electronic conductivity of the working electrode. The "in situ" decomposition behavior of Ag2 Mo2 O7 is distinct from that of chemically synthesized, metal-nanoparticle-coated electrode materials, and provides strong supplementary insight into the mechanism of such new anode materials for SIBs and may set a precedent for the design of further materials.

12.
ACS Omega ; 9(12): 14465-14474, 2024 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-38559971

RESUMEN

Nanofibrous polymeric materials, combined with protein therapeutics, play a significant role in biomedical and pharmaceutical applications. However, the upload of proteins into nanofibers with a high yield and controlled release has been a challenging issue. Here, we report the in situ loading of a model protein (bovine serum albumin) into hydrophilic poly(vinyl alcohol) nanofibers via ice-templating, with a 100% protein drug loading efficiency. These protein-loaded nanofibers were further coated by polydopamine in order to improve the nanofiber stability and achieve a controlled protein release. The mass ratio between poly(vinyl alcohol) and bovine serum albumin influenced the percentage of proteins in composite nanofibers and fiber morphology. More particles and less nanofibers were formed with an increasing percentage of bovine serum albumin. By varying the coating conditions, it was possible to produce a uniform polydopamine coating with tunable thickness, which acted as an additional barrier to reduce burst release and achieve a more sustained release profile.

13.
Artículo en Inglés | MEDLINE | ID: mdl-38587584

RESUMEN

Antimicrobial peptides (AMPs) have the potential to treat multidrug-resistant bacterial infections. Cathelicidins are a class of cationic antimicrobial peptides that are found in nearly all vertebrates. Herein, we determined the mature peptide region of Alligator sinensis cathelicidin by comparing its cathelicidin peptide sequence with those of other reptiles and designed nine peptide mutants based on the Alligator sinensis cathelicidin mature peptide. According to the antibacterial activity and cytotoxicity screening, the peptide AS-12W demonstrated broad-spectrum antibacterial activity and exhibited low erythrocyte hemolytic activity. In particular, AS-12W exhibited strong antibacterial activity and rapid bactericidal activity against carbapenem-resistant Pseudomonas aeruginosa in vitro. Additionally, AS-12W effectively removed carbapenem-resistant P. aeruginosa from blood and organs in vivo, leading to improved survival rates in septic mice. Furthermore, AS-12W exhibited good stability and tolerance to harsh conditions such as high heat, high salt, strong acid, and strong alkali, and it also displayed high stability toward trypsin and simulated gastric fluid (SGF). Moreover, AS-12W showed significant anti-inflammatory effects in vitro by inhibiting the production of proinflammatory factors induced by lipopolysaccharide (LPS). Due to its antibacterial mechanism against Escherichia coli, we found that this peptide could neutralize the negative charge on the surface of the bacteria and disrupt the integrity of the bacterial cell membrane. In addition, AS-12W has the ability to bind to the genomic DNA of bacteria and stimulate the production of reactive oxygen species (ROS) within bacteria, which is believed to be the reason for the good antibacterial activity of AS-12W. These results demonstrated that AS-12W exhibits remarkable antibacterial activity, particularly against carbapenem-resistant P. aeruginosa. Therefore, it is a potential candidate for antibacterial drug development.

14.
Comput Struct Biotechnol J ; 23: 2388-2406, 2024 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38882682

RESUMEN

Antimicrobial peptides are promising therapeutic agents for treating drug-resistant bacterial disease due to their broad-spectrum antimicrobial activity and decreased susceptibility to evolutionary resistance. In this study, three novel cathelicidin antimicrobial peptides were identified from Thamnophis sirtalis, Balaenoptera musculus, and Lipotes vexillifer by protein database mining and sequence alignment and were subsequently named TS-CATH, BM-CATH, and LV-CATH, respectively. All three peptides exhibited satisfactory antibacterial activity and broad antibacterial spectra against clinically isolated E. coli, P. aeruginosa, K. pneumoniae, and A. baumannii in vitro. Among them, TS-CATH displayed the best antimicrobial/bactericidal activity, with a rapid elimination efficiency against the tested drug-resistant gram-negative bacteria within 20 min, and exhibited the lowest cytotoxicity toward mammalian cells. Furthermore, TS-CATH effectively enhanced the survival rate of mice with ceftazidime-resistant E. coli bacteremia and promoted wound healing in meropenem-resistant P. aeruginosa infection. These results were achieved through the eradication of bacterial growth in target organs and wounds, further inhibiting the systemic dissemination of bacteria and the inflammatory response. TS-CATH exhibited direct antimicrobial activity by damaging the inner and outer membranes, resulting in leakage of the bacterial contents at super-MICs. Moreover, TS-CATH disrupted the bacterial respiratory chain, which inhibited ATP synthesis and induced ROS formation, significantly contributing to its antibacterial efficacy at sub-MICs. Overall, TS-CATH has potential for use as an antibacterial agent.

15.
Opt Express ; 21(13): 15755-64, 2013 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-23842362

RESUMEN

We propose a novel and simple method for generating optical vortex with high topological charge (TC), merely using an asymmetrical pinhole plate illuminated by plane wave. N pinholes are arranged along a particular spiral line around the plate origin, with constant azimuth angle increment and varied radial distances. The radial differences introduce a constant variation of m/N wavelength to the optical paths from the N pinholes to the observation plane origin, and this increases the phases of the transmitting waves by progressively 2mπ/Nand totally 2mπ. We numerically calculate the transmitted light field according to the Fresnel diffraction theory, and find the vortex with TC m around the observation plane origin. The experimental verifications are performed using some self-made asymmetrical pinhole plates fabricated by a femtosecond laser, with the high TC vortices both generated and detected in a Mach-Zehnder type interferometer. The experimental results coincide with the theoretical simulations well.

16.
Opt Express ; 21(7): 8831-43, 2013 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-23571973

RESUMEN

This paper reports experimental studies on speckles produced by the rough silver films. The speckles on the rough glass/silver surfaces are measured with a microscopic imaging system. The structures of speckle patterns have the characteristics of fractals and multi-scaled sizes. We find that with the increase of the silver film thickness, the contrast of the speckles increases, and the intensity probability density functions gradually transit to exponential decay. We calculate the global and the local correlation functions of the speckle patterns, and find that both the fractal exponent and correlation length of the small-sized speckles decrease with the thickness of the silver films. We use the mechanisms of rough dielectric interface scattering and random surface plasmon waves to give the preliminary explanations for the evolutions of the speckles.


Asunto(s)
Vidrio/química , Membranas Artificiales , Plata/química , Resonancia por Plasmón de Superficie/métodos , Diseño de Equipo , Análisis de Falla de Equipo , Ensayo de Materiales , Propiedades de Superficie
17.
Res Sq ; 2023 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-37131764

RESUMEN

Background: Amyloid ß (Aß) is a hallmark of Alzheimer's disease (AD). Insufficient sleep duration and poor sleep quality have been found to be a risk factor of developing AD because sleep may involve regulating Aß. However, the magnitude of the relationship between sleep duration and Aß is still unclear. This systematic review examines the relationship between sleep duration and Aß in later-life adults. Methods: We screened 5,005 published articles searched from relevant electronic databases (i.e., PubMed, CINAHL, Embase, and PsycINFO) and reviewed 14 articles for the qualitative synthesis and 7 articles for the quantitative synthesis. Results: Mean ages of the samples ranged from 63 to 76. Studies measured Aß using cerebrospinal fluid, serum, and positron emission tomography scans with two tracers: Carbone 11-labeled Pittsburgh compound B or fluorine 18-labeled. Sleep duration was subjectively measured using interviews, questionnaires, or using objective measures such as polysomnography or actigraphy. The studies accounted for demographic and lifestyle factors in their analyses. Five of the 14 studies reported a statistically significant association between sleep duration and Aß. Using seven eligible articles, our quantitative synthesis demonstrated that the average association between sleep duration and Aß was not statistically significant (Fisher's Z = -0.006, 95% CI= -0.065 ~ 0.054). Conclusion: This review suggests that caution should be taken when considering sleep duration as the primary factor for Aß levels. More studies are needed using a longitudinal design, comprehensive sleep metrics, and larger sample sizes to advance our understanding of the optimal sleep duration and AD prevention.

18.
J Am Med Inform Assoc ; 30(3): 570-587, 2023 02 16.
Artículo en Inglés | MEDLINE | ID: mdl-36458955

RESUMEN

CONTEXT: Over 20% of US adults report they experience pain on most days or every day. Uncontrolled pain has led to increased healthcare utilization, hospitalization, emergency visits, and financial burden. Recognizing, assessing, understanding, and treating pain using artificial intelligence (AI) approaches may improve patient outcomes and healthcare resource utilization. A comprehensive synthesis of the current use and outcomes of AI-based interventions focused on pain assessment and management will guide the development of future research. OBJECTIVES: This review aims to investigate the state of the research on AI-based interventions designed to improve pain assessment and management for adult patients. We also ascertain the actual outcomes of Al-based interventions for adult patients. METHODS: The electronic databases searched include Web of Science, CINAHL, PsycINFO, Cochrane CENTRAL, Scopus, IEEE Xplore, and ACM Digital Library. The search initially identified 6946 studies. After screening, 30 studies met the inclusion criteria. The Critical Appraisals Skills Programme was used to assess study quality. RESULTS: This review provides evidence that machine learning, data mining, and natural language processing were used to improve efficient pain recognition and pain assessment, analyze self-reported pain data, predict pain, and help clinicians and patients to manage chronic pain more effectively. CONCLUSIONS: Findings from this review suggest that using AI-based interventions has a positive effect on pain recognition, pain prediction, and pain self-management; however, most reports are only pilot studies. More pilot studies with physiological pain measures are required before these approaches are ready for large clinical trial.


Asunto(s)
Inteligencia Artificial , Hospitalización , Adulto , Humanos , Dimensión del Dolor , Aprendizaje Automático , Dolor
19.
Opt Express ; 20(16): 17833-42, 2012 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-23038334

RESUMEN

We design an optical setup to extract phase vortices in which the interference intensity of reference light wave and speckle fields produced by random screens with different roughness values in the diffraction region near random screens is obtained. Random screens with different roughness are used as samples. Fourier transform is used to extract speckle phase vortices from the interference intensity, and the experimental results show that the phase vortices can be produced when the roughness of the screen is large enough, and they even may appear on the surface. The density of phase vortices would become larger with an increase of the distances in the diffraction region near the random screen. When the distance is certain, the density of phase vortices becomes larger with the increase of roughness. These results would be helpful for understanding the formation of phase vortices.

20.
Pharmaceutics ; 14(12)2022 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-36559154

RESUMEN

Fibrous materials have unique applications in drug release and biomedical fields. This study reports on the preparation of porous silica nanofibers, using organic nanofibers as templates, and their use for drug release. Different from the commonly used electrospinning method, the organic nanofibers are produced via a self-assembly approach between melamine and benzene-1,3,5-tricarboxylic acid. Silica is then coated on the organic nanofibers via homogenization in a silica sol, a freeze-drying process, and then a sol-gel process. In order to regulate the surface area and mesopore volume of silica nanofibers, cetyltrimethyl ammonium bromide at different concentrations is used as template in the sol-gel process. With the removal of organic nanofibers and the surfactant by calcination, porous silica nanofibers are generated and then assessed as a scaffold for controlled drug release with ketoprofen as a model drug. Poly (D, L-lactide-co-glycolide) is coated on the silica nanofibers to achieve slow burst release and prolonged cumulative release of 25 days. This study demonstrates an effective method of preparing hollow silica nanofibers and the use of such nanofibers for long-term release with high drug loading.

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