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1.
Nano Lett ; 24(3): 943-949, 2024 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-38198687

RESUMEN

Spatiotemporal optical vortices (STOVs) with swirling phase singularities in space and time hold great promise for a wide range of applications across diverse fields. However, current approaches to generate STOVs lack integrability and rely on bulky free-space optical components. Here, we demonstrate routine STOV generation by harnessing the topological darkness phenomenon of a photonic crystal slab. Complete polarization conversion enforced by symmetry enables topological darkness to arise from photonic bands of guided resonances, imprinting vortex singularities onto an ultrashort reflected pulse. Utilizing time-resolved spatial mapping, we provide the first observation of STOV generation using a photonic crystal slab, revealing the imprinted STOV structure manifested as a curved vortex line in the pulse profile in space and time. Our work establishes photonic crystal slabs as a versatile and accessible platform for engineering STOVs and harnessing the topological darkness in nanophotonics.

2.
Opt Lett ; 49(13): 3761-3764, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38950261

RESUMEN

We propose a new, to the best of our knowledge, rainbow technique called three-dimensional rainbow refractometry (TDRR), with a cylindrical lens in the signal collecting system. With a TDRR model based on the ray transfer matrix developed, it is proved that the tilt angle of the rainbow signal is related to the axial position of the droplet, which helps to obtain the 3D position. By converting rainbow scattering angle calibration into the system parameter calibration, a new rainbow data processing program is written in combination with the model to obtain the refractive index and the particle size. With TDRR, we measured a monodisperse droplet stream of deionized water at room temperature for experimental validation and obtained the refractive index with an absolute error of less than 0.0015, the droplet size with an error within ±5%, and the axial position with an error within ±3%, which demonstrated a high accuracy of TDRR.

3.
Environ Sci Technol ; 2024 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-38329941

RESUMEN

Perfluoroalkyl substances (PFAS) are a class of persistent organic pollutants known as "forever chemicals". Currently, the hydrated electron-based advanced reduction process (ARP) holds promise for the elimination of PFAS. However, the efficiency of ARP is often challenged by an oxygen-rich environment, resulting in the consumption of hydrated electron source materials in exchange for the high PFAS decomposition efficiency. Herein, we developed a ternary system constructed by indole and isopropyl alcohol (IPA), and the addition of IPA significantly enhanced the PFOA degradation and defluorination efficiency in the presence of low-concentration indole (<0.4 mM). Meanwhile, opposite results were obtained with a higher amount of indole (>0.4 mM). Further exploring the molecular mechanism of the reaction system, the addition of IPA played two roles. On one hand, IPA built an anaerobic reaction atmosphere and improved the yield and utilization efficiency of hydrated electrons with a low concentration of indole. On the other hand, IPA suppressed the attraction between indole and PFOA, thus reducing the hydrated electron transfer efficiency, especially with more indole. In general, the indole/PFAS/IPA system significantly improved the PFAS destruction efficiency with a small amount of hydrated electron donors, which provided new insights for development of simple and efficient techniques for the treatment of PFAS-contaminated wastewater.

4.
Sensors (Basel) ; 24(10)2024 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-38793959

RESUMEN

Thin copper plate is widely used in architecture, transportation, heavy equipment, and integrated circuit substrates due to its unique properties. However, it is challenging to identify surface defects in copper strips arising from various manufacturing stages without direct contact. A laser ultrasonic inspection system was developed based on the Lamb wave (LW) produced by a laser pulse. An all-fiber laser heterodyne interferometer is applied for measuring the ultrasonic signal in combination with an automatic scanning system, which makes the system flexible and compact. A 3-D model simulation of an H62 brass specimen was carried out to determine the LW spatial-temporal wavefield by using the COMSOL Multiphysics software. The characteristics of the ultrasonic wavefield were extracted through continuous wavelet transform analysis. This demonstrates that the A0 mode could be used in defect detection due to its slow speed and vibrational direction. Furthermore, an ultrasonic wave at the center frequency of 370 kHz with maximum energy is suitable for defect detection. In the experiment, the size and location of the defect are determined by the time difference of the transmitted wave and reflected wave, respectively. The relative error of the defect position is 0.14% by averaging six different receiving spots. The width of the defect is linear to the time difference of the transmitted wave. The goodness of fit can reach 0.989, and it is in good agreement with the simulated one. The experimental error is less than 0.395 mm for a 5 mm width of defect. Therefore, this validates that the technique can be potentially utilized in the remote defect detection of thin copper plates.

5.
Int J Mol Sci ; 25(7)2024 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-38612390

RESUMEN

Dormancy release and reactivation in temperate trees are mainly controlled by temperature and are affected by age, but the underlying molecular mechanisms are still unclear. In this study, we explored the effects of low temperatures in winter and warm temperatures in spring on dormancy release and reactivation in Larix kaempferi. Further, we established the relationships between cell-cycle genes and cambium cell division. The results showed that chilling accelerated L. kaempferi bud break overall, and the longer the duration of chilling is, the shorter the bud break time is. After dormancy release, warm temperatures induced cell-cycle gene expression; when the configuration value of the cell-cycle genes reached 4.97, the cambium cells divided and L. kaempferi reactivated. This study helps to predict the impact of climate change on wood production and provides technical support for seedling cultivation in greenhouses.


Asunto(s)
Larix , Larix/genética , Cámbium , Genes cdc , División Celular , Cambio Climático
6.
Water Sci Technol ; 89(11): 2936-2950, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38877623

RESUMEN

Increasingly frequent urban floods strain the traditional grey infrastructure, overwhelming the capacity of drainage networks and causing challenges in managing stormwater. The heavy precipitation leads to flooding and damage to drainage systems. Consequently, efficient mitigation strategies for flooding have been researched deeply. Green infrastructure (GI) has proved to be effective in responding the increasing risk of flood and alleviate pressure on drainage systems. However, as the primary infrastructure of stormwater management, there is still a lack of attention to the dynamic operation feature of urban sewer systems during precipitation events. To fill this gap, we proposed a novel approach that integrates hydraulic characteristics and the topological structure of a sewer network system. This approach aims to identify influential nodes, which contribute to the connectivity of the sewer network amidst dynamic changes in inflow during precipitation events. Furthermore, we adopted rain barrels to serve as exemplars of GI, and 14 GI layout schemes are produced based on the different ranks of influential nodes. Implementing GI measures on both poorly performing and well-performing nodes can yield distinct benefits in mitigating node flooding. This approach provides a new perspective for stormwater management, establishing effective synergy between GI and the drainage system.


Asunto(s)
Drenaje de Agua , Inundaciones , Lluvia
7.
Environ Sci Technol ; 57(28): 10438-10447, 2023 07 18.
Artículo en Inglés | MEDLINE | ID: mdl-37406161

RESUMEN

Perfluorochemicals (PFCs), especially perfluorooctanoic acid (PFOA), have contaminated the ground and surface waters throughout the world. Efficient removal of PFCs from contaminated waters has been a major challenge. This study developed a novel UV-based reaction system to achieve fast PFOA adsorption and decomposition without addition of sacrificial chemicals by using synthetic photocatalyst sphalerite (ZnS-[N]) with sufficient surface amination and defects. The obtained ZnS-[N] has the capability of both reduction and oxidation due to the suitable band gap and photo-generated hole-trapping properties created by surface defects. The cooperated organic amine functional groups on the surface of ZnS-[N] play a crucial role in the selective adsorption of PFOA, which guarantee the efficient destruction of PFOA subsequently, and 1 µg L-1 PFOA could be degraded to <70 ng L-1 after 3 h in the presence of 0.75 g L-1 ZnS-[N] under 500 W UV irradiation. In this process, the photogenerated electrons (reduction) and holes (oxidation) on the ZnS-[N] surface work in a synergistic manner to achieve complete defluorination of PFOA. This study not only provides promising green technology for PFC-pollution remediation but also highlights the significance of developing a target system capable of both reduction and oxidation for PFC degradation.


Asunto(s)
Aminas , Fluorocarburos , Hidrocarburos Fluorados , Caprilatos/química
8.
Environ Sci Technol ; 57(37): 14071-14081, 2023 09 19.
Artículo en Inglés | MEDLINE | ID: mdl-37681682

RESUMEN

Currently, the lack of model catalysts limits the understanding of the catalytic essence. Herein, we report the functional group modification of model single atom catalysts (SACs) with an accurately regulated electronic structure for accelerating the sluggish kinetics of the Fenton-like reaction. The amino-modified cobalt phthalocyanine anchored on graphene (CoPc/G-NH2) shows superior catalytic performance in the peroxymonosulfate (PMS) based Fenton-like reaction with Co mass-normalized pseudo-first-order reaction rate constants (kobs, 0.2935 min-1), which is increased by 4 and 163 times compared to those of CoPc/G (0.0737 min-1) and Co3O4/G (0.0018 min-1). Density functional theory (DFT) calculations demonstrate that the modification of the -NH2 group narrows the gap between the d-band center and the Fermi level of a single Co atom, which strengthens the charge transfer rate at the reaction interface and reduces the free energy barrier for the activation of PMS. Moreover, the scale-up experiment realizes 100% phenol removal at 7200-bed volumes during 240 h continuous operation without obvious decline in catalytic performance. This work provides in-depth insight into the catalytic mechanism of Fenton-like reactions and demonstrates the electronic engineering of SACs as an effective strategy for improving the Fenton-like activity to achieve the goal of practical application.


Asunto(s)
Electrónica , Contaminantes Ambientales , Catálisis , Cobalto
9.
Environ Sci Technol ; 57(50): 21416-21427, 2023 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-38064647

RESUMEN

Accurately controlling catalytic activity and mechanism as well as identifying structure-activity-selectivity correlations in Fenton-like chemistry is essential for designing high-performance catalysts for sustainable water decontamination. Herein, active center size-dependent catalysts with single cobalt atoms (CoSA), atomic clusters (CoAC), and nanoparticles (CoNP) were fabricated to realize the changeover of catalytic activity and mechanism in peroxymonosulfate (PMS)-based Fenton-like chemistry. Catalytic activity and durability vary with the change in metal active center sizes. Besides, reducing the metal size from nanoparticles to single atoms significantly modulates contributions of radical and nonradical mechanisms, thus achieving selective/nonselective degradation. Density functional theory calculations reveal evolutions in catalytic mechanisms of size-dependent catalytic systems over different Gibbs free energies for reactive oxygen species generation. Single-atom site contact with PMS is preferred to induce nonradical mechanisms, while PMS dissociates and generates radicals on clusters and nanoparticles. Differences originating from reaction mechanisms endow developed systems with size-dependent selectivity and mineralization for treating actual hospital wastewater in column reactors. This work brings an in-depth understanding of metal size effects in Fenton-like chemistry and guides the design of intelligent catalysts to fulfill the demand of specific scenes for water purification.


Asunto(s)
Cobalto , Descontaminación , Catálisis , Agua
10.
Environ Sci Technol ; 57(50): 21459-21469, 2023 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-38056012

RESUMEN

The hydrated electron (eaq-) system is typically suitable for degrading perfluoroalkyl substances (PFASs). To enhance eaq- utilization, we synthesized a new indole compound (DIHA) that forms stable nanospheres (100-200 nm) in water via a supramolecular assembly. Herein, the DIHA nanoemulsion system exhibits high degradation efficiencies toward a broad category of PFASs, regardless of the headgroup, chain length, and branching structure, under UV (254 nm) irradiation. The strong adsorption of PFAS on the DIHA surface ensures its effective degradation/defluorination. Quenching experiments further demonstrated that the reaction took place on the surface of DIHA nanospheres. This specific heterogeneous surface reaction unveiled novel PFAS degradation and defluorination mechanisms that differ from previously reported eaq- systems. First, the photogenerated surface electrons nonselectively attacked multiple C-F bonds of the -CF2- chain. This plays a dominant degrading/defluorinating role in the DIHA system. Second, abundant hydroxyl radicals (•OH) were also produced, leading to synergistic reduction (by surface electron) and oxidation (by surface •OH) in a single system. This facilitates faster and deeper defluorination of different structured PFASs through multiple pathways. The new mechanism inspires the design of innovative organo-heterogeneous eaq- systems possessing synergistic reduction and oxidation functions, thereby making them potentially effective for treating PFAS-contaminated water.


Asunto(s)
Fluorocarburos , Contaminantes Químicos del Agua , Fluorocarburos/análisis , Agua , Oxidación-Reducción , Electrones , Adsorción , Contaminantes Químicos del Agua/análisis
11.
Environ Sci Technol ; 57(41): 15667-15679, 2023 10 17.
Artículo en Inglés | MEDLINE | ID: mdl-37801403

RESUMEN

The nanoconfinement effect in Fenton-like reactions shows great potential in environmental remediation, but the construction of confinement structure and the corresponding mechanism are rarely elucidated systematically. Herein, we proposed a novel peroxymonosulfate (PMS) activation system employing the single Fe atom supported on mesoporous N-doped carbon (FeSA-MNC, specific surface area = 1520.9 m2/g), which could accelerate the catalytic oxidation process via the surface-confinement effect. The degradation activity of the confined system was remarkably increased by 34.6 times compared to its analogue unconfined system. The generation of almost 100% high-valent iron-oxo species was identified via 18O isotope-labeled experiments, quenching tests, and probe methods. The density functional theory illustrated that the surface-confinement effect narrows the gap between the d-band center and Fermi level of the single Fe atom, which strengthens the charge transfer rate at the reaction interface and reduces the free energy barrier for PMS activation. The surface-confinement system exhibited excellent pollutant degradation efficiency, robust resistance to coexisting matter, and adaptation of a wide pH range (3.0-11.0) and various temperature environments (5-40 °C). Finally, the FeSA-MNC/PMS system could achieve 100% sulfamethoxazole removal without significant performance decline after 10,000-bed volumes. This work provides novel and significant insights into the surface-confinement effect in Fenton-like chemistry and guides the design of superior oxidation systems for environmental remediation.


Asunto(s)
Hierro , Peróxidos , Hierro/química , Peróxidos/química , Oxidación-Reducción , Carbono
12.
Environ Sci Technol ; 57(37): 14046-14057, 2023 09 19.
Artículo en Inglés | MEDLINE | ID: mdl-37658810

RESUMEN

Precisely identifying the atomic structures in single-atom sites and establishing authentic structure-activity relationships for single-atom catalyst (SAC) coordination are significant challenges. Here, theoretical calculations first predicted the underlying catalytic activity of Fe-NxC4-x sites with diverse first-shell coordination environments. Substituting N with C to coordinate with the central Fe atom induces an inferior Fenton-like catalytic efficiency. Then, Fe-SACs carrying three configurations (Fe-N2C2, Fe-N3C1, and Fe-N4) fabricate facilely and demonstrate that optimized coordination environments of Fe-NxC4-x significantly promote the Fenton-like catalytic activity. Specifically, the reaction rate constant increases from 0.064 to 0.318 min-1 as the coordination number of Fe-N increases from 2 to 4, slightly influencing the nonradical reaction mechanism dominated by 1O2. In-depth theoretical calculations unveil that the modulated coordination environments of Fe-SACs from Fe-N2C2 to Fe-N4 optimize the d-band electronic structures and regulate the binding strength of peroxymonosulfate on Fe-NxC4-x sites, resulting in a reduced energy barrier and enhanced Fenton-like catalytic activity. The catalytic stability and the actual hospital sewage treatment capacity also showed strong coordination dependency. This strategy of local coordination engineering offers a vivid example of modulating SACs with well-regulated coordination environments, ultimately maximizing their catalytic efficiency.


Asunto(s)
Electrónica , Hospitales , Catálisis , Hierro , Aguas del Alcantarillado
13.
J Hand Ther ; 36(4): 786-795, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37598094

RESUMEN

BACKGROUND: Primary flexor tendon repairs of lacerations in zone II of the hand are fraught with problems. Traditionally, exercise (active and passive), orthoses, and physical agents are common interventions for the rehabilitation of patients experiencing these issues. One area of focus in this field is how to safely utilize tension to lengthen gliding distance following zone II injury. Finding effective solutions in this area is a key priority for improving patient outcomes and quality of life. PURPOSE: To identify the optimal immobilization position that meets safety standards for tension and is the most efficient, and consequently, to validate our clinical effectiveness. STUDY DESIGN: A cross-sectional study was adopted for the first part of the research (Research 1). A prospective, parallel, 2-group, randomized trial was conducted with concealed allocation and single blinding in the second part of the research (Research 2). METHODS: A total of 60 healthy adults were recruited to select the best-fit protective immobilization position in Research 1, which was confirmed by tendon tension (via Young's modulus) and excursion (via gliding distance). We then randomly assigned 45 patients after zone II flexor tendon repair into two groups in Research 2 to compare functional outcomes. The control group underwent the conventional modified Duran protocol with early passive motion, while the experimental group received the protocol (optimized by Research 1) with early active motion. Ultrasonography was used to measure the tension and excursion of the flexor tendons. The outcomes measured at 16 weeks post-repair included total active motion, strength, the Disabilities of the Arm, Shoulder and Hand, and Strickland scores. RESULTS: Three participants were unable to participate in Research 2 due to medical issues and poor attendance. The investigation found that the safe tendon threshold was 345.09 ± 87.74 kPa for partial active digital motion among the 60 participants. The optimal immobilization position requires the wrist to be neutral with a flexion angle of 30° at the metacarpophalangeal joint. The grip strengths (p = 0.012), ratio of grip strength (p = 0.015), the Disabilities of the Arm, Shoulder and Hand (p = 0.036), and total active motion (p = 0.023) differed significantly between the two groups. CONCLUSIONS: Protective immobilization of the wrist in a neutral flexion position and with the metacarpophalangeal joint flexed at 30° can secure the repaired flexor tendon safely and efficiently. The effects of an early active motion protocol may improve the grip strength and upper limb mobility of individuals after zone II flexor tendon repair. CLINICAL TRIAL REGISTRATION: ChiCTR2000030592.


Asunto(s)
Traumatismos de los Dedos , Traumatismos de los Tendones , Adulto , Humanos , Traumatismos de los Tendones/rehabilitación , Estudios Transversales , Estudios Prospectivos , Calidad de Vida , Tendones/cirugía , Traumatismos de los Dedos/cirugía , Ultrasonografía , Rango del Movimiento Articular
14.
Angew Chem Int Ed Engl ; 62(22): e202301719, 2023 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-36988141

RESUMEN

Dynamic materials undergoing adaptive solid-state transitions are attractive for soft mechanics and information technology. Here, we report a novel porous framework system based on macrocyclic trimers assembled from open-shell tetraarylethylene building blocks with aryldicyanomethyl radicals as coupling linkers. Under mechanical, thermal, or chemical stimuli, the framework showed adaptability by activating conformational dynamics and radical-based transformations, thus displaying macroscopic responsiveness in terms of light absorption, luminescence, and magnetism. We studied the dynamic processes by variable-temperature nuclear magnetic resonance (VT-NMR), variable-temperature electron spin resonance (VT-ESR), and superconducting quantum interference device (SQUID) measurement and further established a proof-of-concept application for multi-modal information encryption. The strategy may open avenues for rational design of solid-state photoelectromagnetic dynamic materials by merging dynamic covalent coupling chemistry and functional aggregation principles.

15.
J Neurochem ; 163(2): 133-148, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35892177

RESUMEN

Depression is a global health problem, and there is a pressing need for a better understanding of its pathogenesis. Semaphorin 3B (Sema 3B) is an important axon guidance molecule that is primarily expressed in neurons and contributes to synaptic plasticity. Our previous studies using a high-throughput microarray assay suggested that Sema 3B expression was tremendously decreased during the development of depression, but the specific role and mechanisms of Sema 3B in depression are still unknown. Herein, we report that levels of Sema 3B protein are decreased in the hippocampus and serum of chronic mild stress (CMS)-treated mice. Increasing the levels of Sema 3B, either by injecting AAV-Sema 3B into the hippocampus or by injecting recombinant Sema 3B protein into the lateral ventricles, alleviated CMS-induced depression-like behaviours and enhanced the resistance to acute stress by increasing dendritic spine density in hippocampal neurons. In contrast, interfering with the function of Sema 3B by injecting anti-Sema 3B antibody into the lateral ventricles decreased the resistance to acute stress. In vitro, corticosterone (CORT) treatment decreased the survival rate and protein levels of Sema 3B and synapse-associated proteins in HT22 cells. Overexpression of Sema 3B improved the decreased survival rate caused by CORT by inhibiting apoptosis and increasing levels of synaptic-associated proteins, and knockdown of Sema 3B reduces the cellular resistance to CORT and the levels of synapse-associated proteins. These findings represent the first evidence for the neuroprotective mechanism of Sema 3B against stresses, suggesting that Sema 3B could be a promising novel target for the prevention and treatment of depression.


Asunto(s)
Depresión , Semaforinas , Animales , Ratones , Apoptosis , Corticosterona , Depresión/tratamiento farmacológico , Hipocampo , Plasticidad Neuronal/fisiología , Proteínas , Semaforinas/fisiología , Conducta Animal
16.
Toxicol Appl Pharmacol ; 449: 116131, 2022 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-35718130

RESUMEN

We recently reported that exposure to triclosan (TCS), a broad-spectrum antibacterial agent, affects social behaviors in adult mice, however, the long-lasting effects of TCS exposure during early life on social behaviors are still elusive. The present study aimed to investigate the long-lasting impacts of adding TCS to the maternal drinking water during lactation on the social behaviors of adult mouse offspring and to explore the potential mechanism underlying these effects. The behavioral results showed that TCS exposure decreased body weight, increased depression-like behavior and decreased social dominance in both male and female offspring, as well as increased anxiety-like behavior and bedding preference in female offspring. In addition, enzyme-linked immunosorbent assay (ELISA) indicated that TCS exposure increased peripheral proinflammatory cytokine levels, altered serum oxytocin (OT) levels, and downregulated the expression of postsynaptic density protein 95 (PSD-95) in the hippocampus. Morphological analysis by transmission electron microscopy (TEM) demonstrated that exposure to TCS induced morphological changes to synapses and neurons in the hippocampus of offspring. These findings suggested that TCS exposure during lactation contributed to abnormal social behaviors accompanied by increased peripheral inflammation and altered hippocampal neuroplasticity, which provides a deeper understanding of the effects of TCS exposure during early life on brain function and behavioral phenotypes.


Asunto(s)
Efectos Tardíos de la Exposición Prenatal , Triclosán , Animales , Femenino , Hipocampo , Humanos , Lactancia , Masculino , Exposición Materna/efectos adversos , Ratones , Conducta Social , Triclosán/toxicidad
17.
Opt Lett ; 47(20): 5272-5275, 2022 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-36240340

RESUMEN

This work proposed a synthetic aperture rainbow refractometry (SARR) by synthesizing rainbow signals of the same droplet with dual-wavelength laser beams, in order to increase the aperture of rainbow refractometry. In this way, the SARR can apply to long distance and small droplets measurement. An achromatic imaging system, which simultaneously records while separating the two rainbow signals in two channels of a color image, is elaborately designed. A data processing algorithm is developed to retrieve the optimal droplet refractive index and size. Numerical simulations of different droplet sizes from 10 µm to 200 µm certify the viability of the SARR. Proof-of-concept experiments of micron-sized ethanol droplets are performed with 1650 mm measurement distance. Results show that the SARR can accurately measure droplet refractive index and size with uncertainties of 2.3 × 10-4 and 2µm, respectively. The feasibility and accuracy of the proposed SARR are successfully demonstrated, paving the way for rainbow refractometry applied to large-scale industrial applications.

18.
Langmuir ; 38(40): 12198-12206, 2022 10 11.
Artículo en Inglés | MEDLINE | ID: mdl-36170670

RESUMEN

We reported self-assembled core-shell nanoparticles (NPs) based on lipoprotein-like NPs and plasmid DNA (pDNA). Lipoprotein-like NPs were prepared using cholic acid (CA)-modified lipopeptides. We designed six different lipopeptides with different peptide segments to construct a series of NPs. It was proven that these NPs have different positive surface charges. These NPs could bind pDNA through electrostatic interaction to form core-shell complexes. The interactions between NPs and pDNA were systematically investigated. The number of NP charges determines the strength of the interaction between NPs and pDNA. Thus, various types of core-shell structures, such as loose and dense core-shell NPs, were found in this system. Cytotoxicity test confirmed that the carriers had no toxicity. We also proved that the core-shell structures have a good cell transfection effect. This study would expand the application of lipopeptide assemblies in the gene delivery field, which may lead to the development of peptide-based gene vectors for therapeutic application.


Asunto(s)
ADN , Nanopartículas , Ácido Cólico , ADN/química , ADN/genética , Lipopéptidos , Lipoproteínas , Nanopartículas/química , Nanopartículas/toxicidad , Plásmidos/genética , Transfección
19.
J Vis ; 22(11): 16, 2022 10 04.
Artículo en Inglés | MEDLINE | ID: mdl-36306146

RESUMEN

Sensory decision-making is frequently studied using categorical tasks, even though the feature space of most stimuli is continuous. Recently, it has become more common to measure feature perception in a gradual fashion, say when studying motion perception across the full space of directions. However, continuous reports can be contaminated by perceptual or motor biases. Here, we examined such biases on perceptual reports by comparing two response methods. With the first method, participants reported motion direction in a motor reference frame by moving a trackball. With the second method, participants used a perceptual frame of reference with a perceptual comparison stimulus. We tested biases using three different versions of random dot kinematograms. We found strong and systematic biases in responses when reporting the direction in a motor frame of reference. For the perceptual frame of reference, these systematic biases were not evident. Independent of the response method, we also detected a systematic misperception where subjects sometimes confuse the physical stimulus direction with its opposite direction. This was confirmed using a von Mises mixture model that estimated the contribution of veridical perception, misperception, and guessing. Importantly, the more sensitive perceptual reporting method revealed that, with increasing levels of sensory evidence, perceptual performance increases not only in the form of higher detection probability, but under certain conditions also in the form of increased precision.


Asunto(s)
Percepción de Movimiento , Humanos , Percepción de Movimiento/fisiología , Psicofísica , Simulación por Computador
20.
J Environ Manage ; 314: 115081, 2022 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-35460987

RESUMEN

Starting in 2013, China's key polluting firms have been required to install continuous emissions monitoring systems (CEMS) and to publish the data for real-time oversight and public scrutiny. However, the CEMS data has rarely been used in local environmental law enforcement because its quality is still of great concern. A lack of criteria to evaluate data quality is one of the causes. In this paper, we design a comprehensive analytical framework for evaluating the quality of CEMS data, which includes completeness, accuracy, and authenticity. To demonstrate the applicability of the framework, we build a CEMS dataset for key polluting firms in Henan province from 2017 to 2019 by scraping the CEMS data from a public platform. We then conduct a comprehensive evaluation using our proposed framework. Some data quality issues are identified. About one-third of the firms did not meet official guidelines for data completeness. When comparing the CEMS data with onsite measurement results, we observe statistically significant inconsistencies in about one-fifth of the firms. In addition, we find evidence that some firms might manipulate CEMS data by strategically turning down the CEMS when a pollutant's concentration is expected to exceed the limit. Our framework can be expanded by incorporating more evaluation methods and data. We suggest that government agencies should implement a comprehensive framework to enhance the quality of CEMS data, thereby facilitating its application in law enforcement.


Asunto(s)
Exactitud de los Datos , China
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