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1.
Nature ; 606(7912): 94-101, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35650358

RESUMEN

Neurotransmitters play essential roles in regulating neural circuit dynamics both in the central nervous system as well as at the peripheral, including the gastrointestinal tract1-3. Their real-time monitoring will offer critical information for understanding neural function and diagnosing disease1-3. However, bioelectronic tools to monitor the dynamics of neurotransmitters in vivo, especially in the enteric nervous systems, are underdeveloped. This is mainly owing to the limited availability of biosensing tools that are capable of examining soft, complex and actively moving organs. Here we introduce a tissue-mimicking, stretchable, neurochemical biological interface termed NeuroString, which is prepared by laser patterning of a metal-complexed polyimide into an interconnected graphene/nanoparticle network embedded in an elastomer. NeuroString sensors allow chronic in vivo real-time, multichannel and multiplexed monoamine sensing in the brain of behaving mouse, as well as measuring serotonin dynamics in the gut without undesired stimulations and perturbing peristaltic movements. The described elastic and conformable biosensing interface has broad potential for studying the impact of neurotransmitters on gut microbes, brain-gut communication and may ultimately be extended to biomolecular sensing in other soft organs across the body.


Asunto(s)
Encéfalo , Sistema Nervioso Entérico , Tracto Gastrointestinal , Neurotransmisores , Animales , Técnicas Biosensibles , Encéfalo/metabolismo , Eje Cerebro-Intestino , Elastómeros , Sistema Nervioso Entérico/metabolismo , Tracto Gastrointestinal/inervación , Tracto Gastrointestinal/fisiología , Grafito , Rayos Láser , Ratones , Nanopartículas , Neurotransmisores/análisis , Serotonina/análisis
2.
Anal Chem ; 96(22): 9278-9284, 2024 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-38768425

RESUMEN

Antibody pharmaceuticals have become the most popular immunotherapeutic drugs and are often administered with low serum drug dosages. Hence, the development of a highly sensitive method for the quantitative assay of antibody levels is of great importance to individualized therapy. On the basis of the dual signal amplification by the glycan-initiated site-directed electrochemical grafting of polymer chains (glyGPC), we report herein a novel strategy for the amplified electrochemical detection of antibody pharmaceuticals. The target of interest was affinity captured by a DNA aptamer ligand, and then the glycans of antibody pharmaceuticals were decorated with the alkyl halide initiators (AHIs) via boronate cross-linking, followed by the electrochemical grafting of the ferrocenyl polymer chains from the glycans of antibody pharmaceuticals through the electrochemically controlled atom transfer radical polymerization (eATRP). As the glycans can be decorated with multiple AHIs and the grafted polymer chains are composed of tens to hundreds of electroactive tags, the glyGPC-based strategy permits the dually amplified electrochemical detection of antibody pharmaceuticals. In the presence of trastuzumab (Herceptin) as the target, the glyGPC-based strategy achieved a detection limit of 71.5 pg/mL. Moreover, the developed method is highly selective, and the results of the quantitative assay of trastuzumab levels in human serum are satisfactory. Owing to its uncomplicated operation and cost-effectiveness, the glyGPC-based strategy shows great promise in the amplified electrochemical detection of antibody pharmaceuticals.


Asunto(s)
Aptámeros de Nucleótidos , Técnicas Electroquímicas , Trastuzumab , Técnicas Electroquímicas/métodos , Humanos , Trastuzumab/química , Trastuzumab/sangre , Aptámeros de Nucleótidos/química , Límite de Detección , Polisacáridos/química , Técnicas Biosensibles/métodos , Polímeros/química
3.
Small ; : e2303706, 2024 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-38353067

RESUMEN

Smart windows that can passively regulate incident solar radiation by dynamically modulating optical transmittance have attracted increasing scientific interest due to their potential economic and environmental savings. However, challenges remain in the global adoption of such systems, given the extreme variability in climatic and economic conditions across different geographical locations. Aiming these issues, a methylcellulose (MC) salt system is synthesized with high tunability for intrinsic optical transmittance (89.3%), which can be applied globally to various locations. Specifically, the MC window exhibits superior heat shielding potential below transition temperatures, becoming opaque at temperatures above the Lower Critical Solution Temperature and reducing the solar heat gain by 55%. This optical tunability is attributable to the particle size change triggered by the temperature-induced reversible coil-to-globular transition. This leads to effective refractive index and scattering modulation, making them prospective solutions for light management systems, an application ahead of intelligent fenestration systems. During the field tests, MC-based windows demonstrated a 9 °C temperature decrease compared to double-pane windows on sunny days and a 5 °C increase during winters, with simulations predicting an 11% energy savings. The ubiquitous availability of materials, low cost, and ease-of-manufacturing will provide technological equity and foster the ambition toward net-zero buildings.

4.
Int J Obes (Lond) ; 48(6): 849-858, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38341506

RESUMEN

OBJECTIVE: Fatty acids play a critical role in the proper functioning of the brain. This study investigated the effects of a high-fat (HF) diet on brain fatty acid profiles of offspring exposed to maternal gestational diabetes mellitus (GDM). METHODS: Insulin receptor antagonist (S961) and HF diet were used to establish the GDM animal model. Brain fatty acid profiles of the offspring mice were measured by gas chromatography at weaning and adulthood. Protein expressions of the fatty acid transport pathway Wnt3/ß-catenin and the target protein major facilitator superfamily domain-containing 2a (MFSD2a) were measured in the offspring brain by Western blot. RESULTS: Maternal GDM increased the body weight of male offspring (P < 0.05). In weaning offspring, factorial analysis showed that maternal GDM increased the monounsaturated fatty acid (MUFA) percentage of the weaning offspring's brain (P < 0.05). Maternal GDM decreased offspring brain arachidonic acid (AA), but HF diet increased brain linoleic acid (LA) (P < 0.05). Maternal GDM and HF diet reduced offspring brain docosahexaenoic acid (DHA), and the male offspring had higher DHA than the female offspring (P < 0.05). In adult offspring, factorial analysis showed that HF diet increased brain MUFA in offspring, and male offspring had higher brain MUFA than female offspring (P < 0.05). The HF diet increased brain LA in the offspring. Male offspring had higher level of AA than female offspring (P < 0.05). HF diet reduced DHA in the brains of female offspring. The brain protein expression of ß-catenin and MFSD2a in both weaning and adult female offspring was lower in the HF + GDM group than in the CON group (P < 0.05). CONCLUSIONS: Maternal GDM increased the susceptibility of male offspring to HF diet-induced obesity. HF diet-induced adverse brain fatty acid profiles in both male and female offspring exposed to GDM.


Asunto(s)
Encéfalo , Diabetes Gestacional , Dieta Alta en Grasa , Ácidos Grasos , Efectos Tardíos de la Exposición Prenatal , Animales , Embarazo , Femenino , Diabetes Gestacional/metabolismo , Ratones , Dieta Alta en Grasa/efectos adversos , Encéfalo/metabolismo , Efectos Tardíos de la Exposición Prenatal/metabolismo , Masculino , Ácidos Grasos/metabolismo , Modelos Animales de Enfermedad , Fenómenos Fisiologicos Nutricionales Maternos
5.
Opt Express ; 32(11): 19088-19104, 2024 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-38859052

RESUMEN

Compared with traditional electrical logic gates, optical or terahertz (THz) computing logic gates have faster computing speeds and lower power consumption, and can better meet the huge data computing needs. However, there are limitations inherent in existing optical logic gates, such as single input/output channels and susceptibility to interference. Here, we proposed a new approach utilizing polarization-sensitive graphene-vanadium dioxide metasurface THz logic gates. Benefitting from two actively tunable materials, the proposed controlled-NOT logic gate(CNOT LG) enables versatile functionality through a dual-parameter control system. This system allows for the realization of multiple output states under diverse polarized illuminating conditions, aligning with the expected input-output logic relationship of the CNOT LG. Furthermore, to demonstrate the robustness of the designed THz CNOT LG metasurface, we designed an imaging array harnessing the dynamic control capabilities of tunable meta-atoms, facilitating clear near-field imaging. This research is promising for advancing CNOT LG applications in the THz spectrum. It has potential applications in telecommunications, sensing, and imaging.

6.
Opt Lett ; 49(8): 1927, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38621041

RESUMEN

This publisher's note contains a correction to Opt. Lett.48, 3977 (2023)10.1364/OL.495706.

7.
J Nutr ; 154(2): 590-599, 2024 02.
Artículo en Inglés | MEDLINE | ID: mdl-38159812

RESUMEN

BACKGROUND: Polyunsaturated fatty acids (PUFAs), especially docosahexaenoic acid (DHA), are critical for proper fetal brain growth and development. Gestational diabetes mellitus (GDM) could affect maternal-fetal fatty acid metabolism. OBJECTIVE: This study aimed to explore the effect of GDM and high-fat (HF) diet on the DHA transport signaling pathway in the placenta-brain axis and fatty acid concentrations in the fetal brain. METHODS: Insulin receptor antagonist (S961) and HF diet were used to establish an animal model of GDM. Eighty female C57BL/6J mice were randomly divided into control (CON), GDM, HF, and HF+GDM groups. The fatty acid profiles of the maternal liver and fetal brain were analyzed by gas chromatography. In addition, we analyzed the protein amounts of maternal liver fatty acid desaturase (FADS1/3), elongase (ELOVL2/5) and the regulatory factor sterol-regulatory element-binding protein (SREBP)-1c, and the DHA transport signaling pathway (Wnt3/ß-catenin/MFSD2a) of the placenta and fetal brain using western blotting. RESULTS: GDM promoted the decrease of maternal liver ELOVL2, ELOVL5, and SREBP-1c. Accordingly, we observed a significant decrease in the amount of maternal liver arachidonic acid (AA), DHA, and total n-3 PUFA and n-6 PUFA induced by GDM. GDM also significantly decreased the amount of DHA and n-3 PUFA in the fetal brain. GDM downregulated the Wnt3/ß-catenin/MFSD2a signaling pathway, which transfers n-3 PUFA in the placenta and fetal brain. The HF diet increased n-6 PUFA amounts in the maternal liver, correspondingly increasing linoleic acid, gamma-linolenic acid, AA, and total n-6 PUFA in the fetal brain, but decreased DHA amount in the fetal brain. However, HF diet only tended to decrease placental ß-catenin and MFSD2a amounts (P = 0.074 and P = 0.098, respectively). CONCLUSIONS: Maternal GDM could affect the fatty acid profile of the fetal brain both by downregulating the Wnt3/ß-catenin/MFSD2a pathway of the placental-fetal barrier and by affecting maternal fatty acid metabolism.


Asunto(s)
Diabetes Gestacional , Ácidos Grasos Omega-3 , Humanos , Animales , Ratones , Femenino , Embarazo , Diabetes Gestacional/metabolismo , Ácidos Grasos/metabolismo , Placenta/metabolismo , beta Catenina/metabolismo , Ratones Endogámicos C57BL , Ácidos Grasos Omega-3/metabolismo , Ácidos Grasos Insaturados/metabolismo , Ácidos Docosahexaenoicos/metabolismo , Ácido Araquidónico , Encéfalo/metabolismo
8.
Endocr J ; 2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38777757

RESUMEN

Acute sleep deprivation has aroused widespread concern and the relationship between acute sleep deprivation and cortisol levels is inconsistent. This study aimed to explore additional evidence and details. The PubMed, Web of Science, EMBASE, CLINAHL and Cochrane databases were searched for eligible studies published up to June 7, 2023. All analyses were performed using Review Manager 5.4 and Stata/SE 14.0. A total of 24 studies contributed to this meta-analysis. There was no significant difference in cortisol levels between participants with acute sleep deprivation and normal sleep in 21 crossover-designed studies (SMD = 0.18; 95% CI: -0.11, 0.45; p = 0.208) or 3 RCTs (SMD = 0.26; 95% CI: -0.22, 0.73; p = 0.286). Subgroup analysis revealed that the pooled effects were significant for studies using serum as the sample (SMD = 0.46; 95%CI: 0.11, 0.81; p = 0.011). Studies reporting cortisol levels in the morning, in the afternoon and in the evening did not show significant difference (p > 0.05). The pooled effects were statistically significant for studies with multiple measurements (SMD = 0.28; 95%CI: 0.03, 0.53; p = 0.027) but not for studies with single cortisol assessments (p = 0.777). When the serum was used as the test sample, the cortisol levels of individuals after acute sleep deprivation were higher than those with normal sleep.

9.
Aging Ment Health ; : 1-13, 2024 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-38946249

RESUMEN

OBJECTIVES: To systematically evaluate the effects of telehealth interventions on the caregiver burden and mental health of caregivers for people with dementia (PWD). METHOD: Relevant randomized controlled trials (RCTs) of telehealth interventions on caregivers were extracted from nine electronic databases (PubMed, The Cochrane Library, Web of Science, Embase, CINAHL, SinoMed, CNKI, WanFang, and VIP). The retrieval time was from inception to 26 July 2023. RESULTS: Twenty-two articles with 2132 subjects were included in the final analysis. The meta-analysis demonstrated that telehealth interventions exerted a significant effect in reducing caregiver burden (SMD: -0.14, 95 % CI: -0.25, -0.02, p = 0.02), depression (SMD = -0.17; 95%CI: -0.27, -0.07, p < 0.001) and stress (SMD = -0.20, 95%CI: -0.37, -0.04, p = 0.01). However, no statistically significant effect was observed on anxiety (SMD = -0.12, 95%CI: -0.27, 0.03, p = 0.12). Moreover, subgroup analysis showed that tailored interventions were associated with more evident reductions in depression (SMD = -0.26; 95%CI: -0.40, -0.13, p < 0.001) than standardized interventions (SMD = -0.08; 95%CI: -0.22, 0.06, p = 0.25). In addition, telehealth was effective in relieving depression in Internet-based (SMD = -0.17, 95%CI: -0.30, -0.03, p = 0.01) and Telephone-based group (SMD = -0.18, 95%CI: -0.34, -0.02, p = 0.03), while there was no significant difference in the Internet and Telephone-based group (SMD = -0.18, 95%CI: -0.54, 0.18, p = 0.32). CONCLUSION: Telehealth could effectively reduce the burden and relieve the depression and stress of caregivers of PWD, while its effect on anxiety requires further research. Overall, telehealth has potential benefits in dementia care.

10.
Anal Chem ; 95(23): 9043-9051, 2023 06 13.
Artículo en Inglés | MEDLINE | ID: mdl-37262441

RESUMEN

Smart materials can dynamically and reversibly change their structures and functions in response to external stimuli. In this study, we designed a smart magnetic composite (MNP-pSPA-b-pNIPAm) with a triple response to ultraviolet (UV) light, pH, and temperature. Relying on the response of spiropyranyl acrylate (SPA) and N-isopropylacrylamide (NIPAm) to external stimuli (light, pH, and temperature), MNP-pSPA-b-pNIPAm was used for the controlled capture and release of phosphopeptides. The established phosphopeptide enrichment platform exhibits high sensitivity (detection limit of 0.04 fmol), high selectivity (BSA/ß-casein, 1000:1), and good reusability (6 cycles). In addition, the method was also applied to the enrichment of phosphopeptides in real samples (skim milk, human saliva, and serum), demonstrating the feasibility of this method for phosphoproteomic analysis. After enriching from human nonsmall cell lung cancer cell (A549) lysates with MNP-pSPA-b-pNIPAm, 2595 phosphopeptides corresponding to 2281 phosphoproteins were identified. The novel responsive enrichment probe is highly specific for phosphoproteomic analysis and provides an effective method for studying the significance of protein phosphorylation in complex biological samples.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Humanos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Fosfopéptidos/análisis , Temperatura , Fenómenos Magnéticos , Concentración de Iones de Hidrógeno , Titanio/química
11.
Opt Lett ; 48(7): 1606-1609, 2023 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-37221721

RESUMEN

Vector vortex beams (VVBs) with non-uniform polarization states have a wide range of applications, from particle capture to quantum information. Here, we theoretically demonstrate a generic design for all-dielectric metasurfaces operating in the terahertz (THz) band, characterized as a longitudinal evolution from scalar vortices carrying homogeneous polarization states to inhomogeneous vector vortices with polarization singularities. The order of the converted VVBs can be arbitrarily tailored by manipulating the topological charge embedded in two orthogonal circular polarization channels. The introduction of the extended focal length and the initial phase difference effectively guarantees the smoothness of the longitudinal switchable behavior. A generic design approach based on vector-generated metasurfaces can assist in the exploration of new singular properties of THz optical fields.

12.
BMC Nurs ; 22(1): 29, 2023 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-36732804

RESUMEN

BACKGROUND: High turnover intention of nursing assistants was detrimental to the sustainability of long-term care. Career adaptability is an important determinant in reducing turnover intention, but little research has explored the mechanism from the perspective of psychological capital. The aim of this study was to analyze the association between career adaptability and turnover intention and to examine the mediating role of psychological capital between career adaptability and turnover intention among nursing assistants in mainland China. METHODS: A cross-sectional online study was conducted among 276 nursing assistants from eight nursing homes in Nanjing, China. The participants' career adaptability, psychological capital, and turnover intention were obtained. SPSS 26.0 and Amos 24.0 software were employed for statistical analysis. RESULTS: Career adaptability was positively related to psychological capital and negatively linked to turnover intention (P < 0.01). Psychological capital played a fully mediating role (ß = -0.085, P < 0.05) in the relationship between career adaptability and turnover intention, and the largest indirect effect was generated through the curiosity dimension. CONCLUSIONS: The management of long-term care facilities should focus on assessing the level of career adaptability of nursing assistants. The overall improvement of career adaptability and psychological capital is conducive in reducing turnover intention. Targeted interventions are recommended to improve career adaptability and reduce turnover intentions by increasing career curiosity. Online career adaptability programs can be developed for nursing assistant students to improve their psychological capital and facilitate career transitions.

13.
Biochem Biophys Res Commun ; 595: 7-13, 2022 03 05.
Artículo en Inglés | MEDLINE | ID: mdl-35091109

RESUMEN

The intestinal tract is an essential component of the body's immune system, and is extremely sensitive to exposure of ionizing radiation. While ionizing radiation can effectively induce multiple forms of cell death, whether it can also promote ferroptosis in intestinal cells and the possible interrelationship between ferroptosis and intestinal immune function has not been reported so far. Here, we found that radiation-induced major ultrastructural changes in mitochondria of small intestinal epithelial cells and the changes induced in iron content and MDA levels in the small intestine were consistent with that observed during cellular ferroptosis, thus suggesting occurrence of ferroptosis in radiation-induced intestinal damage. Moreover, radiation caused a substantial increase in the expression of ferroptosis-related factors such as LPCAT3 and ALOX15 mRNA, augmented the levels of immune-related factors INF-γ and TGF-ß mRNA, and decreased the levels of IL-17 mRNA thereby indicating that ionizing radiation induced ferroptosis and impairment of intestinal immune function. Liproxstatin-1 is a ferroptosis inhibitor that was found to ameliorate radiation-induced ferroptosis and promote the recovery from immune imbalances. These findings supported the role of ferroptosis in radiation-induced intestinal immune injury and provide novel strategies for protection against radiation injury through regulation of the ferroptosis pathway.


Asunto(s)
Ferroptosis/fisiología , Intestinos/patología , Quinoxalinas/farmacología , Traumatismos Experimentales por Radiación/prevención & control , Radiación Ionizante , Compuestos de Espiro/farmacología , 1-Acilglicerofosfocolina O-Aciltransferasa/genética , 1-Acilglicerofosfocolina O-Aciltransferasa/metabolismo , Animales , Araquidonato 12-Lipooxigenasa/genética , Araquidonato 12-Lipooxigenasa/metabolismo , Araquidonato 15-Lipooxigenasa/genética , Araquidonato 15-Lipooxigenasa/metabolismo , Ferroptosis/efectos de los fármacos , Ferroptosis/efectos de la radiación , Expresión Génica/efectos de los fármacos , Expresión Génica/efectos de la radiación , Glutatión/metabolismo , Intestino Delgado/efectos de los fármacos , Intestino Delgado/metabolismo , Intestino Delgado/efectos de la radiación , Intestinos/efectos de los fármacos , Intestinos/efectos de la radiación , Masculino , Malondialdehído/metabolismo , Ratones Endogámicos BALB C , Microscopía Electrónica de Transmisión , Mitocondrias/efectos de los fármacos , Mitocondrias/efectos de la radiación , Mitocondrias/ultraestructura , Traumatismos Experimentales por Radiación/patología , Traumatismos Experimentales por Radiación/fisiopatología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Superóxido Dismutasa/metabolismo
14.
Diabetes Metab Res Rev ; 38(4): e3522, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35080114

RESUMEN

BACKGROUND: The relationship between serum selenium level and gestational diabetes mellitus (GDM) is controversial. The purpose is to update and summarize previous studies to understand the relationship in more detail. METHODS: PubMed, The Cochrane Library, EMBASE, Web of science, CNKI, WANFANG DATA and Cqvip were searched for studies published up to 3 September 2021. The random-effects model was used to measure the combined estimation. The overall effect was reported in a standard mean difference (SMD) and 95% confidence interval (95% CI). All data were analysed by Review Manager 5.4. RESULTS: Twenty-seven studies involving 1588 patients with GDM and 2450 healthy pregnant women contributed to this meta-analysis. Selenium level was significantly lower in women with GDM than those without GDM (SMD = -1.29; 95% CI: -1.60 to -0.97, p < 0.00001). Subgroup analyses showed that such trend was consistent within the non-European population (Asia: SMD = -1.44; 95% CI: -1.79 to -1.08, p < 0.00001; Africa: SMD = -2.62; 95% CI: -4.50 to -0.74, p = 0.006) and in the second and third trimesters (the second trimester: SMD = -1.41; 95% CI: -1.82 to -0.99, p < 0.00001; the third trimester: SMD = -1.54; 95% CI: -2.09 to -0.98, p < 0.00001), but not within the European population (SMD = -0.47; 95% CI: -1.09 to 0.16, p = 0.14) or in the first trimester (SMD = -0.52; 95% CI: -1.13 to 0.10, p = 0.10). CONCLUSIONS: This meta-analysis showed that the serum selenium level of patients with GDM was lower than that in healthy pregnant women, especially within the non-European population and in the second and third trimesters.


Asunto(s)
Diabetes Gestacional , Selenio , Femenino , Humanos , Embarazo , Primer Trimestre del Embarazo , Segundo Trimestre del Embarazo , Tercer Trimestre del Embarazo
15.
Microsc Microanal ; : 1-11, 2022 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-35260221

RESUMEN

Accurate geometrical calibration between the scan coordinates and the camera coordinates is critical in four-dimensional scanning transmission electron microscopy (4D-STEM) for both quantitative imaging and ptychographic reconstructions. For atomic-resolved, in-focus 4D-STEM datasets, we propose a hybrid method incorporating two sub-routines, namely a J-matrix method and a Fourier method, which can calibrate the uniform affine transformation between the scan-camera coordinates using raw data, without a priori knowledge of the crystal structure of the specimen. The hybrid method is found robust against scan distortions and residual probe aberrations. It is also effective even when defects are present in the specimen, or the specimen becomes relatively thick. We will demonstrate that a successful geometrical calibration with the hybrid method will lead to a more reliable recovery of both the specimen and the electron probe in a ptychographic reconstruction. We will also show that, although the elimination of local scan position errors still requires an iterative approach, the rate of convergence can be improved, and the residual errors can be further reduced if the hybrid method can be firstly applied for initial calibration. The code is made available as a simple-to-use tool to correct affine transformations of the scan-camera coordinates in 4D-STEM experiments.

16.
Opt Express ; 29(24): 40652-40667, 2021 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-34809400

RESUMEN

High degree of coherence is essential in coherent diffraction imaging (CDI). The coherence requirement on the light source varies with the experimental configuration. As a scanning variant of CDI, ptychography has shown great potential for extensive applications. To determine the influence of partially temporal and spatial coherence on near- and far-field ptychography, we have performed a series of numerical simulations and visible light optical experiments. We demonstrated that the near-field is more robust to spatial and temporal decoherence than the far-field. In addition, the far-field is found to be more sensitive to spatial decoherence than to temporal decoherence. Our experiments also show that a known probe estimate with good spatial coherence enables the retrieval qualities to be enhanced dramatically and helps prevent falling into the local minimums in the reconstruction process. Our work would provide a valuable reference for implementing ptychography with sources of limited coherence.

17.
Opt Express ; 29(20): 31426-31442, 2021 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-34615235

RESUMEN

Reconstruction of a complex field from one single diffraction measurement remains a challenging task among the community of coherent diffraction imaging (CDI). Conventional iterative algorithms are time-consuming and struggle to converge to a feasible solution because of the inherent ambiguities. Recently, deep-learning-based methods have shown considerable success in computational imaging, but they require large amounts of training data that in many cases are difficult to obtain. Here, we introduce a physics-driven untrained learning method, termed Deep CDI, which addresses the above problem and can image a dynamic process with high confidence and fast reconstruction. Without any labeled data for pretraining, the Deep CDI can reconstruct a complex-valued object from a single diffraction pattern by combining a conventional artificial neural network with a real-world physical imaging model. To our knowledge, we are the first to demonstrate that the support region constraint, which is widely used in the iteration-algorithm-based method, can be utilized for loss calculation. The loss calculated from support constraint and free propagation constraint are summed up to optimize the network's weights. As a proof of principle, numerical simulations and optical experiments on a static sample are carried out to demonstrate the feasibility of our method. We then continuously collect 3600 diffraction patterns and demonstrate that our method can predict the dynamic process with an average reconstruction speed of 228 frames per second (FPS) using only a fraction of the diffraction data to train the weights.

18.
Br J Nutr ; 126(8): 1121-1129, 2021 10 28.
Artículo en Inglés | MEDLINE | ID: mdl-33331250

RESUMEN

In the present study, we analysed the effects of SNP rs174547 (T/C) in the fatty acid desaturase 1 (FADS1) gene on long-chain PUFA levels. Four databases were searched to retrieve related literature with keywords such as fatty acid (FA), SNP, FADS1 and rs174547. A meta-analysis of the data was performed using Stata12.0 software, including summary statistics, test for heterogeneity, evaluation of publication bias, subgroup analysis and sensitivity analysis. The associations between rs174547 in FADS1 and seven types of FA, and Δ-5 (D5D) and Δ-6 fatty acid desaturase (D6D) activity were assessed based on the pooled results from eleven papers. A total of 3713 individuals (1529 TT and 2184 TC + CC) were included. The results demonstrated that minor C allele carriers of rs174547 had higher linoleic acid (LA; P < 0·001) and α-linolenic acid (P = 0·020) levels, lower γ-linolenic acid (GLA; P = 0·001) and arachidonic acid (P = 0·024) levels, and lower D5D (P = 0·005) and D6D (P = 0·004) activities than the TT genotype group. Stratification analysis showed that minor C allele carriers of rs174547 had higher LA and lower GLA levels and lower D6D activities in plasma (LA, P < 0·001; GLA, P < 0·001; D6D activity, P < 0·001) samples and in Asian populations (LA, P < 0·001; GLA, P = 0·001; D6D activity, P = 0·001) than the TT genotype group. In conclusion, minor C allele carriers of the SNP rs174547 were associated with decreased activity of D5D and D6D.


Asunto(s)
delta-5 Desaturasa de Ácido Graso/genética , Ácidos Grasos Insaturados/sangre , Polimorfismo de Nucleótido Simple , Alelos , Ácido Araquidónico , Humanos , Ácido Linoleico , Ácido alfa-Linolénico , Ácido gammalinolénico
19.
Bioorg Med Chem ; 51: 116495, 2021 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-34781083

RESUMEN

Four new 19-nor-clerodane diterpenoids (1-4), one new 15,16-dinor-ent-pimarane diterpenoid (5) together with four known diterpenoids (6-9) were isolated from whole plants of Croton yunnanensis. The structures of these compounds were determined by extensive spectroscopic methods including 1D, 2D NMR, HR-ESI-MS, and by comparing their NMR data with those of previously reported compounds. The experimental and calculated electronic circular dichroism data were used to define their absolute configurations. The 1H and 13C NMR spectra of 6 were completely assigned for the first time. All isolated compounds (1-9) were evaluated for their cytotoxic activities against five human cancer cell lines (including SMMC-7721, HL-60, A-549, MCF-7, and SW-480), and anti-inflammatory activities in LPS-induced RAW264.7 macrophages. Crotonyunnan E (5) exhibited selective cytotoxicities against three tumor cell lines, SMMC-7721 (human hepatoma cells, IC50 4.47 ± 0.39 µM), HL-60 (human premyelocytic leukemia, IC50 14.38 ± 1.19 µM), and A-549 (human lung cancer cells, IC50 27.42 ± 0.48 µM), while none of the compounds showed obviously anti-inflammatory activities at 50 µM level.


Asunto(s)
Antiinflamatorios no Esteroideos/farmacología , Antineoplásicos Fitogénicos/farmacología , Croton/química , Diterpenos/farmacología , Extractos Vegetales/farmacología , Animales , Antiinflamatorios no Esteroideos/química , Antiinflamatorios no Esteroideos/aislamiento & purificación , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/aislamiento & purificación , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Teoría Funcional de la Densidad , Diterpenos/química , Diterpenos/aislamiento & purificación , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Lipopolisacáridos/antagonistas & inhibidores , Lipopolisacáridos/farmacología , Ratones , Estructura Molecular , Óxido Nítrico/antagonistas & inhibidores , Óxido Nítrico/biosíntesis , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación , Células RAW 264.7 , Relación Estructura-Actividad
20.
Opt Express ; 28(26): 40060-40074, 2020 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-33379540

RESUMEN

An actively reconfigurable broadband terahertz (THz) metamaterial functional device based on the phase-change material vanadium dioxide (VO2) and two-dimensional graphene material is theoretically proposed and demonstrated. The device has excellent tolerance under oblique incidence. When the VO2 is in the metallic state, and the Fermi energy of graphene is fixed at 0.1 eV, the designed device acts as a broadband THz absorber in the transverse magnetic (TM) polarization mode. The absorptance bandwidth exceeds 0.55 THz with a complete absorption intensity of more than 90%. In this state, the absorber operates as a broadband modulator with the total modulation depth exceeding 91.5% as the continually decreased conductivity of VO2 from 200000 S/m to 10 S/m. In the transverse electric (TE) polarization process, the structure behaves as a dual-band absorber with two perfect absorption peaks. When the conductivity of VO2 is changed, the tunable absorber can also be regarded as an absorptance modulator, with a maximum modulation intensity of 92.1%. Alternatively, when VO2 behaves as an insulator at room temperature in the TE polarization mode, a strong broadband electromagnetically induced transparency (EIT) window is obtained, with a bandwidth exceeding 0.42 THz in the transmittance spectrum. By varying the Fermi energy of graphene from 0 to 0.9 eV, the EIT-like window or broadband transmission spectrum (in TM mode) can be switched. The results indicate that the device can also be operated as a modulator in the transmission mode. The impedance matching theory is used, and electric field distributions are analyzed to quantify the physical mechanism. An advantage of the manipulation of the polarization angle is that the modulation performance of the proposed multi-functional THz device can be regulated after fabricated.

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