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1.
J Chem Phys ; 159(17)2023 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-37933785

RESUMEN

The formation of electron and hole traps in semiconductors via atomistic defects is the fundamental microscopic mechanism for tuning the electronic and photonic properties of these materials. Here we find in experiments that bismuth atoms doped into anatase TiO2 as substituents can appear as paired diatomic defects. Through first-principles density functional theory calculations, we reveal that the observed bismuth pair is separated by a medium distance of 6.37 Å through a delicate balance of Pauli repulsion and effective attractive interaction. We further clarify that the effective attractive interaction is related to the exchange coupling between the two bismuth defect states, which also leads to the formation of a spin singlet electronic state of the two unpaired electrons. Our study brings up a new type of defect state in TiO2, and motivates further experimental and theoretical studies of multi-electronic states in materials.

2.
Sensors (Basel) ; 23(2)2023 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-36679709

RESUMEN

Land surface temperatures (LST) are vital parameters in land surface-atmosphere interactions. Constrained by technology and atmospheric interferences, LST retrievals from various satellite sensors usually return missing data, thus negatively impacting analyses. Reconstructing missing data is important for acquiring gap-free datasets. However, the current reconstruction methods are limited for maintaining spatial details and high accuracies. We developed a new gap-free algorithm termed the spatial feature-considered random forest regression (SFRFR) model; it builds stable nonlinear relationships to connect the LST with related parameters, including terrain elements, land coverage types, spectral indexes, surface reflectance data, and the spatial feature of the LST, to reconstruct the missing LST data. The SFRFR model reconstructed gap-free LST data retrieved from the Landsat 8 satellite on 27 July 2017 in Wuhan. The results show that the SFRFR model exhibits the best performance according to the various evaluation metrics among the SFRFR, random forest regression and spline interpolation, with a coefficient of determination (R2) reaching 0.96, root-mean-square error (RMSE) of 0.55, and mean absolute error (MAE) of 0.55. Then, we reconstructed gap-free LST data gathered in Wuhan from 2016 to 2021 to analyze urban thermal environment changes and found that 2020 presented the coolest temperatures. The SFRFR model still displayed satisfactory results, with an average R2 of 0.91 and an MAE of 0.63. We further discuss and discover the factors affecting the visual performance of SFRFR and identify the research priority to circumvent these disadvantages. Overall, this study provides a simple, practical method for acquiring gap-free LST data to help us better understand the spatiotemporal LST variation process.


Asunto(s)
Algoritmos , Monitoreo del Ambiente , Temperatura , Monitoreo del Ambiente/métodos , Ciudades , China
3.
Phys Chem Chem Phys ; 24(25): 15330-15339, 2022 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-35703342

RESUMEN

The premelting layer plays an important role in ice growth, but there is a significant gap in our knowledge between the atomistic premelting surface structure and the macroscopic growth mechanism. In this work, using large-scale molecular dynamics simulation, we reveal the existence of clusters on the premelting surface, as an intermediate feature bridging the gap. We show the spontaneous formation and evolution of clusters, and they form a stable distribution determined by the growth rate. We demonstrate how this stable distribution is related to the growth mode of ice, connected by the growth of clusters. We come to a bilayer-by-bilayer growth mode at simulation-reachable high growth rates, but another mechanism, namely "cluster stacking", is speculated to exist at lower growth rates. This work builds a connection between the microscopic structure of the premelting layer and the macroscopic growth of ice, making a step forward toward the full understanding of premelting and ice growth.

4.
Can J Microbiol ; 68(3): 215-226, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34855458

RESUMEN

Vibrio harveyi can cause infections and diseases in a variety of marine vertebrates and invertebrates, which are harmful to the aquaculture industry. The LuxS quorum-sensing system regulates the expression of virulence factors in a wide variety of pathogenic bacteria. In this study, an in-frame deletion of the luxS gene was constructed to reveal the role of LuxS in the physiology and virulence of V. harveyi. Statistical analysis showed no significant differences in the growth ability, biofilm formation, antibiotic susceptibility, virulence by intraperitoneal injection, and ability of V. harveyi to colonize the spleen and liver of the pearl gentian grouper between the wild-type (WT) and luxS mutant. However, deletion of luxS decreased the secretion of extracellular protease, while increasing swimming and swarming abilities. Simultaneously, a luxS-deleted mutant showed overproduction of lateral flagella, and an intact luxS complemented this defect. Since motility is flagella dependent, 16 V. harveyi flagella biogenesis related genes were selected for further analysis. Based on quantitative real-time reverse transcription-PCR (qRT-PCR), the expression levels of these genes, including the polar flagella genes flaB, flhA, flhF, flhB, flhF, fliS, and flrA and the lateral flagella genes flgA, flgB, fliE, fliF, lafA, lafK, and motY, were significantly upregulated in the ΔluxS: pMMB207 (ΔluxS+) strain as compared with the V. harveyi 345: pMMB207 (WT+) and C-ΔluxS strains during the early, mid-exponential, and stationary growth phases. Our results indicate that LuxS plays an important role in controlling motility, flagella biogenesis, and extracellular protease secretion in V. harveyi.


Asunto(s)
Péptido Hidrolasas , Vibrio , Animales , Proteínas Bacterianas/metabolismo , Liasas de Carbono-Azufre/metabolismo , Regulación Bacteriana de la Expresión Génica , Péptido Hidrolasas/genética , Péptido Hidrolasas/metabolismo , Vibrio/genética
5.
Microb Pathog ; 157: 104965, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34015493

RESUMEN

Vibrio harveyi is a Gram-negative bacterium that occurs widely in the ocean and a kind of pathogenic bacteria associated with vibriosis in grouper. We investigated whether the VscCD protein of the type Ⅲ secretion system (T3SS) was important for pathogenicity of V. harveyi. Mutations to the vscC and vscD genes (ΔvscCD) and complementation of the ΔvscCD mutant (C-ΔvscCD) were created. Moreover, the biological characteristics of the wild-type (WT) and mutant strains of V. harveyi 345 were compared. The results showed that deletion of the vscCD genes had no effect on bacterial growth, swimming/swarming ability, secretion of extracellular protease, or biofilm formation. However, as compared with the V. harveyi 345: pMMB207 (WT+) and complementary (C-ΔvscCD) strains, the ΔvscCD: pMMB207 (ΔvscCD+) mutant displayed decreased resistance to acid stress, H2O2, and antibiotics. In addition, infection of the pearl gentian grouper (♀Epinephelus fuscoguttatus × â™‚Epinephelus lanceolatu) showed that as compared with the WT+ and C-ΔvscCD strains, the ΔvscCD+ strain significantly reduced cumulative mortality of the host. The colonization ability of the ΔvscCD+ mutant in the spleen and liver tissues of the pearl gentian grouper was significantly lower than that of the WT+ and C-ΔvscCD strains. In the early stage of infection with the ΔvscCD+ strain, the expression levels of IL-1ß, IL-16, TLR3, TNF-α, MHC-Iα, and CD8α were up-regulated to varying degrees. As compared with the WT+ and C-ΔvscCD strains, luxR expression was significantly up-regulated in the ΔvscCD+ strain, while the expression of vcrH and vp1668 was significantly down-regulated. As an important component of the T3SS, VscCD seemed to play a significant role in the pathogenesis of V. harveyi.


Asunto(s)
Enfermedades de los Peces , Vibriosis , Vibrio , Animales , Peróxido de Hidrógeno , Sistemas de Secreción Tipo III/genética , Vibrio/genética , Vibriosis/veterinaria
6.
BMC Musculoskelet Disord ; 22(1): 236, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33648479

RESUMEN

BACKGROUND: Recently, a percutaneous spinal endoscopy unilateral posterior interlaminar approach to perform bilateral decompression has been proposed for use in treatment of lumbar spinal stenosis, As a development and supplement to traditional surgery, its advantages regarding therapeutic effects and prognosis, such as minor soft tissue damage, little intraoperative blood loss, and a quick return to daily life. However, there are few analyses of this surgery with a follow-up of more than 1 year,we conducted this study in order to quantitatively investigate radiographic and clinical efficacies of this surgery for central lumbar spinal stenosis. MATERIALS AND METHODS: Forty-six patients with central lumbar spinal stenosis were enrolled from January 2017 to July 2018. The visual analog scale (VAS) for back pain and leg pain, Oswestry disability index (ODI), modified MacNab criteria were used to evaluate clinical efficiency at preoperative and postoperative time points. The intervertebral height index (IHI), cross-sectional area of the spinal canal (CSAC), calibrated disc signal (CDS) and spinal stability were examined to assess radiographic decompression efficiency via magnetic resonance imaging and X-ray at preoperative and postoperative time points. RESULTS: The VAS score for lower back pain and leg pain improved from 7.50 ± 0.78 to 1.70 ± 0.66 and from 7.30 ± 0.79 to 1.74 ± 0.68, respectively, and the ODI improved from 72.35 ± 8.15 to 16.15 ± 4.51. In terms of modified MacNab criteria, 91.3% of the patients achieved good or excellent outcomes. Furthermore, significant changes after surgery were observed for the percentage of CSAC, increasing from 125.3 ± 53.9 to 201.4 ± 78 mm2; however, no significant differences were observed for the remaining measurement indicators. CONCLUSIONS: The clinical and radiographic efficacies of this surgery for central lumbar spinal stenosis were good in short-term follow-up, and this surgery did not cause meaningful changes in IHI, CDS, and spine stability in short-term follow-up. The effect of long-term follow-up needs further investigation.


Asunto(s)
Estenosis Espinal , Descompresión Quirúrgica , Endoscopía , Humanos , Vértebras Lumbares/diagnóstico por imagen , Vértebras Lumbares/cirugía , Estenosis Espinal/diagnóstico por imagen , Estenosis Espinal/cirugía , Resultado del Tratamiento
7.
J Mater Sci Mater Med ; 33(1): 2, 2021 Dec 23.
Artículo en Inglés | MEDLINE | ID: mdl-34940930

RESUMEN

Anterior spine decompression and reconstruction with bone grafts and fusion is a routine spinal surgery. The intervertebral fusion cage can maintain intervertebral height and provide a bone graft window. Titanium fusion cages are the most widely used metal material in spinal clinical applications. However, there is a certain incidence of complications in clinical follow-ups, such as pseudoarticulation formation and implant displacement due to nonfusion of bone grafts in the cage. With the deepening research on metal materials, the properties of these materials have been developed from being biologically inert to having biological activity and biological functionalization, promoting adhesion, cell differentiation, and bone fusion. In addition, 3D printing, thin-film, active biological material, and 4D bioprinting technology are also being used in the biofunctionalization and intelligent advanced manufacturing processes of implant devices in the spine. This review focuses on the biofunctionalization of implant materials in 3D printed intervertebral fusion cages. The surface modifications of implant materials in metal endoscopy, material biocompatibility, and bioactive functionalizationare summarized. Furthermore, the prospects and challenges of the biofunctionalization of implant materials in spinal surgery are discussed. Fig.a.b.c.d.e.f.g As a pre-selected image for the cover, I really look forward to being selected. Special thanks to you for your comments.


Asunto(s)
Materiales Biocompatibles/síntesis química , Investigación Biomédica/tendencias , Impresión Tridimensional , Diseño de Prótesis/tendencias , Fusión Vertebral/instrumentación , Animales , Materiales Biocompatibles/química , Investigación Biomédica/métodos , Sustitutos de Huesos/síntesis química , Sustitutos de Huesos/química , Trasplante Óseo/instrumentación , Trasplante Óseo/métodos , Trasplante Óseo/tendencias , Humanos , Impresión Tridimensional/tendencias , Prótesis e Implantes , Diseño de Prótesis/métodos , Fusión Vertebral/métodos , Fusión Vertebral/tendencias
8.
Appl Microbiol Biotechnol ; 104(5): 2229-2241, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31915903

RESUMEN

The aquatic microbial community is sensitive to environmental change; however, the impacts of those changes combined with disease outbreaks affecting S. paramamosain are unknown. Thus, from March to October, we explored the interaction between aquacultural environmental conditions and microbial composition and function in open-air aquaculture ponds containing S. paramamosain in Southern China. The microbial community structure was significantly positively correlated with microbial community function. The environment variables such as temperature and salinity during May and June changed more quickly compared with other periods, resulting changes in the structure and function of the microbial community affected S. paramamosain survivability, with higher crab mortality observed from May to June compared with other periods. These included changes in the relative abundance of Microtrichales, Synechococcales, Rhodobacterales, Chitinophagales, and SAR11_clade, and corresponding functions associated with glycolysis and/or gluconeogenesis, porphyrin and chlorophyll metabolism, photosynthetic proteins, and transcription factors. These changes could impact S. paramamosain mortality and be used to evaluate the health status of the ponds. Though the environment variables during July~October changed slowly comparing to May and June, the ponds microflora changed which benefit S. paramamosain survivability with correspondingly low S. paramamosain mortality. Therefore, rapid environmental change alters the structure and function of the aquatic microflora, increasing S. paramamosain mortality.


Asunto(s)
Braquiuros/fisiología , Microbiota , Estanques/microbiología , Microbiología del Agua , Animales , Acuicultura , China , Monitoreo del Ambiente , Microbiota/genética , Nutrientes/análisis , Estanques/química , Salinidad , Estaciones del Año , Temperatura
9.
Appl Opt ; 59(9): 2754-2758, 2020 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-32225824

RESUMEN

Mode converters play an essential role in mode-division multiplexing systems. A reflective mode converter (RMC), which is utilized to accomplish the mode conversion in the contra-propagation process, can fold the optical path and realize the mode exchange in an optical network. In this paper, we propose and experimentally demonstrate an RMC based on a silicon subwavelength structure. It can convert the input fundamental mode (${\text{TE}_0}$TE0) into the first-order mode (${\text{TE}_1}$TE1) in a ${2.0}\;\unicode{x00B5} \text{m} \times {2.0}\;\unicode{x00B5} \text{m}$2.0µm×2.0µm footprint. The simulated insertion loss and cross talk are lower than 0.6 dB and $ - {20.3}\;\text{dB}$-20.3dB in 1525-1565 nm. Experimental results verify the functionality of the device. The measured insertion loss and cross talk are lower than 2.2 dB and $ - {16.2}\;\text{dB}$-16.2dB. To further prove the generality of the methodology, we design another two RMCs realizing the mode conversion functions of ${\text{TE}_0}$TE0 to ${\text{TE}_2}$TE2 and ${\text{TE}_0}$TE0 to ${\text{TE}_3}$TE3 modes. The simulated insertion losses are lower than 1.1 dB and 1.8 dB.

10.
Opt Lett ; 44(17): 4179-4182, 2019 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-31465357

RESUMEN

The mode-order converter is a building block in a multimode optical transmission and switching system. It can be used for switching signals carried on different mode channels. However, such devices constructed by conventional structures can commonly accomplish one mode-order conversion process. It is because the phase-matching condition, which is utilized by a majority of designs, can usually be fulfilled between only one mode pair for specific device geometry. In this Letter, we propose a dual-polarization mode-order converter referring to the concept of a silicon planar metasurface. It can realize mode-order conversions on transverse electrical and transverse magnetic polarizations in parallel. In order to verify our concept, we design and experimentally demonstrate a prototype that can realize conversions from TE0 to TE1 and from TM0 to TM1 simultaneously. The footprint is 4 µm×1.6 µm. The measured insertion losses for both polarizations are smaller than 2.3 dB, and the crosstalk is lower than -11.5 dB within the wavelength range of 1525-1565 nm. We envision that the device can be a building block in polarization and mode multiplexed optical switching systems and endow the systems with simpler structure and a more compact footprint.

11.
Pharm Res ; 36(12): 182, 2019 Nov 18.
Artículo en Inglés | MEDLINE | ID: mdl-31741089

RESUMEN

PURPOSE: Combination chemotherapy is gradually receiving more attention because of its potential synergistic effect and reduced drug doses in clinical application. However, how to precisely control drug release dose and time using vehicles remains a challenge. This work developed an efficient drug delivery system to combat breast cancer, which can enhance drug effects despite reducing its concentration. METHODS: Controlled-release poly-lactic-co-glycolic acid (PLGA) scaffolds were fabricated by E-jet 3D printing to deliver doxorubicin (DOX) and cisplatin (CDDP) simultaneously. RESULTS: This drug delivery system allowed the use of a reduced drug dosage resulting in a better effect on the human breast cancer cell apoptosis and inhibiting tumor growth, compared with the effect of each drug and the two drugs administrated without PLGA scaffolds. Our study suggested that DOX-CDDP-PLGA scaffolds could efficiently destroy MDA-MB-231 cells and restrain tumor growth. CONCLUSIONS: The 3D printed PLGA scaffolds with their time-programmed drug release might be useful as a new multi-drug delivery vehicle in cancer therapy, which has a potential advantage in a long term tumor cure and prevention of tumor recurrence.


Asunto(s)
Antineoplásicos/química , Cisplatino/química , Doxorrubicina/química , Portadores de Fármacos/química , Copolímero de Ácido Poliláctico-Ácido Poliglicólico/química , Animales , Antineoplásicos/administración & dosificación , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Neoplasias de la Mama/tratamiento farmacológico , Línea Celular Tumoral , Permeabilidad de la Membrana Celular , Supervivencia Celular/efectos de los fármacos , Cisplatino/administración & dosificación , Cisplatino/farmacología , Doxorrubicina/administración & dosificación , Doxorrubicina/farmacología , Liberación de Fármacos , Quimioterapia Combinada/métodos , Excipientes/química , Femenino , Humanos , Ratones , Ratones Endogámicos BALB C , Impresión Tridimensional
12.
Sensors (Basel) ; 19(3)2019 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-30759733

RESUMEN

This paper considers a reconnaissance task assignment problem for multiple unmanned aerial vehicles (UAVs) with different sensor capacities. A modified Multi-Objective Symbiotic Organisms Search algorithm (MOSOS) is adopted to optimize UAVs' task sequence. A time-window based task model is built for heterogeneous targets. Then, the basic task assignment problem is formulated as a Multiple Time-Window based Dubins Travelling Salesmen Problem (MTWDTSP). Double-chain encoding rules and several criteria are established for the task assignment problem under logical and physical constraints. Pareto dominance determination and global adaptive scaling factors is introduced to improve the performance of original MOSOS. Numerical simulation and Monte-Carlo simulation results for the task assignment problem are also presented in this paper, whereas comparisons with non-dominated sorting genetic algorithm (NSGA-II) and original MOSOS are made to verify the superiority of the proposed method. The simulation results demonstrate that modified SOS outperforms the original MOSOS and NSGA-II in terms of optimality and efficiency of the assignment results in MTWDTSP.


Asunto(s)
Aeronaves/instrumentación , Algoritmos , Inteligencia Artificial , Método de Montecarlo
13.
Sensors (Basel) ; 18(10)2018 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-30322108

RESUMEN

In this paper, we study the influence of multipath magnitude, bandwidth, and communication link number on the performance of the existing time-reversal (TR) based fingerprinting localization approach and find that the localization accuracy deteriorates with a limited bandwidth. To improve the localization performance, by exploiting two unique location-specified signatures extracted from Channel State Information (CSI), we propose a high accuracy TR fingerprint localization approach, HATRFLA. Furthermore, we employ a density-based spatial clustering algorithm to minimize the storage space of the fingerprint database by adaptively selecting the optimal number of fingerprints for each location. Experimental results confirm that the proposed approach can efficiently mitigate accuracy deterioration caused by a limited bandwidth and consequently, achieve higher accuracy compared with the existing TR localization approach.

14.
Artículo en Inglés | MEDLINE | ID: mdl-39012751

RESUMEN

Neural radiance fields (NeRF) have achieved great success in novel view synthesis and 3D representation for static scenarios. Existing dynamic NeRFs usually exploit a locally dense grid to fit the deformation fields; however, they fail to capture the global dynamics and concomitantly yield models of heavy parameters. We observe that the 4D space is inherently sparse. Firstly, the deformation fields are sparse in spatial but dense in temporal due to the continuity of motion. Secondly, the radiance fields are only valid on the surface of the underlying scene, usually occupying a small fraction of the whole space. We thus represent the 4D scene using a learnable sparse latent space, a.k.a. SLS4D. Specifically, SLS4D first uses dense learnable time slot features to depict the temporal space, from which the deformation fields are fitted with linear multi-layer perceptions (MLP) to predict the displacement of a 3D position at any time. It then learns the spatial features of a 3D position using another sparse latent space. This is achieved by learning the adaptive weights of each latent feature with the attention mechanism. Extensive experiments demonstrate the effectiveness of our SLS4D: It achieves the best 4D novel view synthesis using only about 6% parameters of the most recent work.

15.
Environ Pollut ; 349: 123917, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38583794

RESUMEN

Phthalate esters (PAEs) are plasticizers widely used in the industry and easily released into the environment, posing a serious threat to human health. Molecularly imprinted polymers (MIPs) are important as selective adsorbents for the removal of PAEs. In this study, three kinds of mussel-inspired MIPs for the removal of PAEs were first prepared with gallic acid (GA), hexanediamine (HD), tannic acid (TA), and dopamine (DA) under mild conditions. The adsorption results showed that the MIP with low cost derived from GA and HD (GAHD-MIP) obtained the highest adsorption capacity among these materials. Furthermore, 97.43% of equilibrium capacity could be reached within the first 5 min of adsorption. Especially, the dummy template of diallyl phthalate (DAP) with low toxicity was observed to be more suitable to prepare MIPs than dibutyl phthalate (DBP), although DBP was the target of adsorption. The adsorption process was in accordance with the pseudo-second-order kinetics model. In the isotherm analysis, the adsorption behavior agreed with the Freundlich model. Additionally, the material maintained high adsorption performance after 7 cycles of regeneration tests. The GAHD-MIP adsorbents in this study, with low cost, rapid adsorption equilibrium, green raw materials, and low toxicity dummy template, provide a valuable reference for the design and development of new MIPs.


Asunto(s)
Dibutil Ftalato , Ácido Gálico , Polímeros Impresos Molecularmente , Contaminantes Químicos del Agua , Adsorción , Dibutil Ftalato/química , Contaminantes Químicos del Agua/química , Ácido Gálico/química , Polímeros Impresos Molecularmente/química , Ácidos Ftálicos/química , Cinética , Purificación del Agua/métodos
16.
Vet Sci ; 11(7)2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-39057977

RESUMEN

The spleen is the largest peripheral immune organ of the organism, accounting for 25% of the total lymphoid tissue of the body. During HS, the spleen is damaged due to the elevated environment, which seriously affects life performance and broilers' health. This study aimed to investigate the mechanism of chronic HS damage to broiler spleen tissues. The broilers were typically raised until they reached 21 days of age, after which they were arbitrarily allocated into two groups: an HS group and a cntrol group. The HS group was subjected to a temperature of 35 °C for 10 h each day, starting at 21 days of age. At 35 and 42 days of age, spleen and serum samples were obtained from the broilers. The results showed that after HS, a significant decrease in productive performance was observed at 42 days of age (p < 0.01), and the spleen index, and bursa index were significantly decreased (p < 0.01). T-AOC of the organism was significantly decreased (p < 0.05), GSH-PX, SOD, and CAT antioxidant factors were significantly decreased (p < 0.01), and MDA was significantly elevated (p < 0.01). HS also led to a significant increase in cytokines IL-6, TNF-α, and INF-γ and a significant decrease in IL-4 in the spleen. The histopathologic results showed that the spleen's red-white medulla was poorly demarcated. The cells were sparsely arranged after HS. After HS, the expression of TLRs, MYD88, and NF-κB genes increased significantly. The expression of HSP70 increased significantly, suggesting that HS may induces an inflammatory response in broiler spleens through this signaling pathway, which may cause pathological damage to broiler spleens, leading to a decrease in immune function and progressively aggravating HS-induced damage with the prolongation of HS.

17.
J Funct Biomater ; 14(2)2023 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-36826896

RESUMEN

Rapid, accurate, and portable on-site detection is critical in the face of public health emergencies. Infectious disease control and public health emergency policymaking can both be aided by effective and trustworthy point of care tests (POCT). A very promising POCT method appears to be the clustered regularly interspaced short palindromic repeats and associated protein (CRISPR/Cas)-based molecular diagnosis. For on-site detection, CRISPR/Cas-based detection can be combined with multiple signal sensing methods and integrated into smart devices. In this review, sensing methods for CRISPR/Cas-based diagnostics are introduced and the advanced strategies and recent advances in CRISPR/Cas-based POCT are reviewed. Finally, the future perspectives of CRISPR and POCT are summarized and prospected.

18.
IEEE Trans Vis Comput Graph ; 29(4): 1977-1991, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-34941511

RESUMEN

Maintaining global consistency continues to be critical for online 3D indoor scene reconstruction. However, it is still challenging to generate satisfactory 3D reconstruction in terms of global consistency for previous approaches using purely geometric analysis, even with bundle adjustment or loop closure techniques. In this article, we propose a novel real-time 3D reconstruction approach which effectively integrates both semantic and geometric cues. The key challenge is how to map this indicative information, i.e., semantic priors, into a metric space as measurable information, thus enabling more accurate semantic fusion leveraging both the geometric and semantic cues. To this end, we introduce a semantic space with a continuous metric function measuring the distance between discrete semantic observations. Within the semantic space, we present an accurate frame-to-model semantic tracker for camera pose estimation, and semantic pose graph equipped with semantic links between submaps for globally consistent 3D scene reconstruction. With extensive evaluation on public synthetic and real-world 3D indoor scene RGB-D datasets, we show that our approach outperforms the previous approaches for 3D scene reconstruction both quantitatively and qualitatively, especially in terms of global consistency.

19.
IEEE Trans Image Process ; 32: 6401-6412, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37976196

RESUMEN

This paper presents a Semantic Positioning System (SPS) to enhance the accuracy of mobile device geo-localization in outdoor urban environments. Although the traditional Global Positioning System (GPS) can offer a rough localization, it lacks the necessary accuracy for applications such as Augmented Reality (AR). Our SPS integrates Geographic Information System (GIS) data, GPS signals, and visual image information to estimate the 6 Degree-of-Freedom (DoF) pose through cross-view semantic matching. This approach has excellent scalability to support GIS context with Levels of Detail (LOD). The map data representation is Digital Elevation Model (DEM), a cost-effective aerial map that allows for fast deployment for large-scale areas. However, the DEM lacks geometric and texture details, making it challenging for traditional visual feature extraction to establish pixel/voxel level cross-view correspondences. To address this, we sample observation pixels from the query ground-view image using predicted semantic labels. We then propose an iterative homography estimation method with semantic correspondences. To improve the efficiency of the overall system, we further employ a heuristic search to speedup the matching process. The proposed method is robust, real-time, and automatic. Quantitative experiments on the challenging Bund dataset show that we achieve a positioning accuracy of 73.24%, surpassing the baseline skyline-based method by 20%. Compared with the state-of-the-art semantic-based approach on the Kitti dataset, we improve the positioning accuracy by an average of 5%.

20.
Anal Chim Acta ; 1251: 341014, 2023 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-36925313

RESUMEN

The accumulation and spread of antibiotic resistance bacteria (ARB) in the environment may accelerate the formation of superbugs and seriously threaten the health of all living beings. The timeliness and accurate diagnosing of antibiotic resistance is essential to controlling the propagation of superbugs in the environment and formulating effective public health management programs. Herein, we developed a speedy, sensitive, accurate, and user-friendly colorimetric assay for antibiotic resistance, via a synergistic combination of the peroxidase-like property of the Au-Fe3O4 nanozyme and the specific gene identification capability of the CRISPR-Cas12a. Once the CRISPR-Cas12a system recognizes a target resistance gene, it activates its trans-cleavage activity and subsequently releases the Au-Fe3O4 nanozymes, which oxidizes the 3,3,5,5-tetramethylbenzidine (TMB) with color change from transparent to blue. The diagnosing signals could be captured and analyzed by a smartphone. This method detected kanamycin-resistance genes, ampicillin-resistance genes, and chloramphenicol-resistance genes by simple operation steps with high sensitivity (<0.1 CFU µL-1) and speediness (<1 h). This approach may prove easy for the accurate and sensitive diagnosis of the ARGs or ARB in the field, thus surveilling and controlling the microbial water quality flexibly and efficiently.


Asunto(s)
Antagonistas de Receptores de Angiotensina , Inhibidores de la Enzima Convertidora de Angiotensina , Sistemas CRISPR-Cas , Ampicilina , Farmacorresistencia Microbiana/genética
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