Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 72
Filtrar
1.
Anal Chem ; 96(19): 7687-7696, 2024 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-38693877

RESUMEN

Smart theranostic nanoprobes with the integration of multiple therapeutic modalities are preferred for precise diagnosis and efficient therapy of tumors. However, it remains a big challenge to arrange the imaging and two or more kinds of therapeutic agents without weakening the intended performances. In addition, most existing fluorescence (FL) imaging agents suffer from low spatiotemporal resolution due to the short emission wavelength (<900 nm). Here, novel three-in-one Ag2S quantum dot (QD)-based smart theranostic nanoprobes were proposed for in situ ratiometric NIR-II FL imaging-guided ion/gas combination therapy of tumors. Under the acidic tumor microenvironment, three-in-one Ag2S QDs underwent destructive degradation, generating toxic Ag+ and H2S. Meanwhile, their FL emission at 1270 nm was weakened. Upon introduction of a downconversion nanoparticle (DCNP) as the delivery carrier and NIR-II FL reference signal unit, the formed Ag2S QD-based theranostic nanoprobes could achieve precise diagnosis of tumors through ratiometric NIR-II FL signals. Also, the generated Ag+ and H2S enabled specific ion/gas combination therapy toward tumors. By combining the imaging and therapeutic functions, three-in-one Ag2S QDs may open a simple yet reliable avenue to design theranostic nanoprobes.


Asunto(s)
Imagen Óptica , Puntos Cuánticos , Compuestos de Plata , Puntos Cuánticos/química , Compuestos de Plata/química , Humanos , Animales , Ratones , Rayos Infrarrojos , Nanomedicina Teranóstica , Sulfuro de Hidrógeno/análisis , Sulfuro de Hidrógeno/química , Concentración de Iones de Hidrógeno
2.
Ambio ; 2024 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-38653867

RESUMEN

Protected areas (PAs) are effective in mitigating human pressures, yet their future pressure alleviating effects remain unclear. In this study, we employed the ConvLSTM model to forecast the future human footprint and analyzed human pressure trends using Theil-Sen median and Mann-Kendall tests. We further evaluated the mitigating effects of PAs within their buffer zones (1-10 km) and the contributions of different IUCN categories of PAs to mitigating human pressure using linear regression models. The results indicate that by 2035, the average human pressure value is expected to increase by 11%, with trends exhibiting a polarized pattern. Furthermore, PAs also effectively mitigate human pressure within their 1 km buffer zones. Different categories of PAs vary in their effectiveness in mitigating human pressure, and stricter conservation areas are not always the most effective. This study can offer insights for evaluating the effectiveness of PAs in reducing human pressure and advocate for their targeted management in urban areas.

3.
Curr Eye Res ; : 1-8, 2024 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-38679893

RESUMEN

PURPOSE: To investigate the effects of resveratrol (Res) on human fetal scleral fibroblasts (HFSFs) and its potential mechanism. METHODS: HFSFs were randomly divided into the Res-treated group and the control group. Following, HFSFs were treated with or without a concentration of 10 µM Res for 48 h. To detect the expression of related genes, reverse transcription quantitative PCR (RT-qPCR) and western blotting were used. The apoptosis rate of different groups was determined using flow cytometry. RESULTS: The mRNA expression of matrix metalloproteinase 2 (MMP-2), Collagen, Type I, Alpha 1 (COL1A1), Janus Kinase 2 (JAK2), and Signal Transducer and Activator of Transcription 3 (STAT3)" was downregulated in the Res-treatment group compared to the control group, according to RT-qPCR. Western blotting revealed that Res therapy reduced the expression of MMP-2, JAK2, P-JAK2, STAT3, P-STAT3, and Bcl-2 associated protein X (Bax) while increasing the expression of COL1A1 and B-cell lymphoma-2 (Bcl-2). Flow cytometry showed that the cell apoptosis rate was significantly lower in HFSFs treated with Res. CONCLUSIONS: In conclusion, these findings suggest that Res increases COL1A1 expression while inhibiting MMP-2 and cell apoptosis in HFSFs, possibly through modulation of the JAK2/STAT3 signaling pathway.

4.
Sci Rep ; 14(1): 6126, 2024 03 13.
Artículo en Inglés | MEDLINE | ID: mdl-38480842

RESUMEN

We demonstrate an adaptation of deep learning for label-free imaging of the micro-scale lymphatic vessels and aqueous veins in the eye using optical coherence tomography (OCT). The proposed deep learning-based OCT lymphangiography (DL-OCTL) method was trained, validated and tested, using OCT scans (23 volumetric scans comprising 19,736 B-scans) from 11 fresh ex vivo porcine eyes with the corresponding vessel labels generated by a conventional OCT lymphangiography (OCTL) method based on thresholding with attenuation compensation. Compared to conventional OCTL, the DL-OCTL method demonstrates comparable results for imaging lymphatics and aqueous veins in the eye, with an Intersection over Union value of 0.79 ± 0.071 (mean ± standard deviation). In addition, DL-OCTL mitigates the imaging artifacts in conventional OCTL where the OCT signal modelling was corrupted by the tissue heterogeneity, provides ~ 10 times faster processing based on a rough comparison and does not require OCT-related knowledge for correct implementation as in conventional OCTL. With these favorable features, DL-OCTL promises to improve the practicality of OCTL for label-free imaging of lymphatics and aqueous veins for preclinical and clinical imaging applications.


Asunto(s)
Aprendizaje Profundo , Vasos Linfáticos , Animales , Porcinos , Tomografía de Coherencia Óptica/métodos , Ojo , Vasos Linfáticos/diagnóstico por imagen , Linfografía/métodos
5.
J Biomech ; 166: 112047, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38484653

RESUMEN

To maintain the physiological dynamics of the mitral annulus, mitral annuloplasty rings (MAR) must be flexible. Enhanced flexibility implies decreased resistance to fatigue and potential for fatigue fracture. This study established new methods to test the flexible fatigue life of MAR in-vitro using numerical analysis; the purpose is that the fatigue test could reflect the real stress distribution in-vivo. Based on the conventional test methods (C1, D1), this paper presents a novel test method (C2, D2). Four testing methods for open-end annuloplasty rings (C1, C2) and closed-end annuloplasty rings (D1, D2) were modelled and their stress distribution calculated by finite element analysis. The mean absolute error (Χ) and the Pearson correlation coefficient (Φ) were used to quantify the difference in stress distribution between the loading modes in-vivo and in-vitro. For closed-end annuloplasty rings, the novel test method (D2) is not obvious better than conventional test methods(D1) in duplicating the stress distribution (ΦD1 = 0.88 vs ΦD2 = 0.92). However, the maximum values of stress in the novel test method are closer to the maximum value of stress under in-vivo loading (ΧD1 = 5.2Mpa vs ΧD2 = 4.4Mpa). For open-end annuloplasty rings, the novel test method(C2) is obviously superior to the conventional test method(C1) in duplicating both the stress distribution and the stress peak values of the in-vivo loading (ΦC1 = 0.22 vs ΦC2 = 0.98; ΧC1 = 59.1Mpa vs ΧC2 = 11.0Mpa). The in-vitro loading methods described in this article more closely approximated in-vivo conditions compared to traditional methods. They are simpler to operate, more efficient and can help manufacturers expedite new product development, assist regulatory agencies with product quality oversight.


Asunto(s)
Implantación de Prótesis de Válvulas Cardíacas , Prótesis Valvulares Cardíacas , Anuloplastia de la Válvula Mitral , Insuficiencia de la Válvula Mitral , Humanos , Diseño de Prótesis , Anuloplastia de la Válvula Mitral/métodos , Válvula Mitral/cirugía , Válvula Mitral/fisiología , Ensayo de Materiales , Insuficiencia de la Válvula Mitral/cirugía
6.
J Infect Dev Ctries ; 17(11): 1574-1580, 2023 11 30.
Artículo en Inglés | MEDLINE | ID: mdl-38064395

RESUMEN

INTRODUCTION: Biosafety research requires a wide range of microorganisms and thorough disinfection to prevent laboratory infection is often required. Ultraviolet-C (UV-C) exposure reduces bacterial and viral concentrations. Therefore, in this study, we aimed to evaluate the efficacy of a mobile UV-C device as a non-contact disinfection strategy. METHODOLOGY: The bactericidal efficacy of the UV-C device was determined based on log10 decreases in the relative abundances of bacterial indicators, including Escherichia coli, Staphylococcus aureus, Staphylococcus albus, and Pseudomonas aeruginosa at 0.5 and 1.0 m after irradiation for 30, 60, and 90 min. Next, the reduction of natural bacteria in air and on surface as a result of the UV-C device exposure in the laboratory were determined. RESULTS: Exposure to the UV-C disinfection device resulted in mean log10 decreases in microbial contamination of 3.55 and 5.85 following irradiation for 30 and 90 min, respectively, at a distance of 0.5 m. Further, P. aeruginosa and E. coli were the most and least sensitive to UV-C exposure, respectively. The bacterial load in air decreased by 65.53% after 60 min of irradiation, while those on surfaces decreased by 44.19% and 78.23% after 30 and 60 min of irradiation, respectively. CONCLUSIONS: The UV-C device effectively reduced bacterial load after irradiation for over 60 min. Further studies are encouraged to determine the effectiveness of the UV-C disinfection device in frequently occupied institutions, such as primary medical, health, and nursery, and its efficiency in infection control.


Asunto(s)
Escherichia coli , Laboratorios , Desinfección/métodos , Contención de Riesgos Biológicos , Bacterias , Pseudomonas aeruginosa , Rayos Ultravioleta
7.
Case Rep Gastrointest Med ; 2023: 4966879, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37849821

RESUMEN

Aeromonas species are capable of inducing severe infections in both immunocompetent and immunocompromised individuals. Gastroenteritis is the most common infection associated with Aeromonas species in humans. We report a rare case of Aeromonas caviae severe gastroenteritis and bloody diarrhea that led to the development of sepsis in a 45-year-old female with no history of immunocompromising conditions. This patient required extensive medical support which included blood transfusions and antibiotics. Fortunately, with appropriate diagnostic measures and targeted antibiotic therapy, her symptoms resolved. Aeromonas species are becoming increasingly frequent among the pathogens isolated from patients suffering from gastroenteritis. As such, it is becoming increasingly important for clinicians to consider this pathogen when working up their patients for diarrhea.

8.
J R Coll Physicians Edinb ; 53(4): 265-268, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37905373

RESUMEN

Cytomegalovirus (CMV) usually causes infections with mild symptoms in immunocompetent individuals. However, in immunocompromised patients, these infections can be serious or life-threatening. Following initial infection, CMV typically becomes dormant but remains lifelong in the host. Reactivation of the latent virus can occur in many organ systems, including the gastrointestinal (GI) tract. Radiation proctitis is a known risk factor associated with prostate radiation, with complicating ulceration and GI bleeding. We present the first case report of an immunocompetent 81-year-old male with multiple episodes of life-threatening GI bleeding, secondary to a non-healing CMV-positive rectal ulcer and CMV colitis following radiation for prostate cancer. Multiple insults including prostate radiation, repeated blood transfusions and CMV infection likely contributed to the recurrent bleeding episodes.


Asunto(s)
Infecciones por Citomegalovirus , Proctitis , Masculino , Humanos , Anciano de 80 o más Años , Citomegalovirus , Hemorragia Gastrointestinal/etiología , Infecciones por Citomegalovirus/complicaciones , Infecciones por Citomegalovirus/diagnóstico , Proctitis/complicaciones , Factores de Riesgo , Úlcera/complicaciones
9.
Chem Sci ; 14(11): 3070-3075, 2023 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-36937597

RESUMEN

Upconversion nanoparticles enable indirect activation of photodynamic therapy (PDT) using near-infrared (NIR) light, providing an excellent alternative for treating deep tumors. However, conventional NIR light-triggered PDT systems suffered from low spatiotemporal accuracy and restricted therapeutic efficiency in vivo. In this work, DNA logic circuits were functionally modified on down/upconversion nanoparticles (D/UCNPs) to construct smart down/upconversion nanomachines (D/UCNMs) for NIR light-triggered PDT toward target tumors. Upon dual inputs of tumor-associated GSH and TK1 mRNA, DNA logic circuits perform "AND" logic computation and initiate the toehold-mediated strand displacement reaction. Meanwhile, the quenched upconversion fluorescence was recovered and then the approaching photosensitizers were activated, leading to in situ output of singlet oxygen (1O2) for precise and enhanced PDT. Importantly, the biodistribution of the D/UCNMs in vivo could be visualized by second near-infrared (NIR-II) fluorescence imaging via the downconversion luminance of D/UCNPs, which further contributed to performing precise PDT. This work provides new insights into the development of precise and highly efficient PDT systems.

10.
Anal Chem ; 94(50): 17645-17652, 2022 12 20.
Artículo en Inglés | MEDLINE | ID: mdl-36475450

RESUMEN

Slow intermolecular collisions and "always active" responses compromise the amplification efficiency and response accuracy of nonenzymatic hybridization chain reaction (HCR). In this study, a photoactivatable membrane-oriented HCR (MOHCR) system was rationally designed by binding a photocleavable initiator probe onto a target protein and then anchoring cholesterol-modified hairpin-structure fuel probes. When irradiated, the bound initiator probe was photoactivated and initiated self-assembly to generate activatable and amplified imaging. In a proof-of-concept assay, breast-cancer-derived exosomes were imaged based on the surface protein epithelial cell adhesion molecule (EpCAM). Photoactivatable responses provided precise spatiotemporal control of the MOHCR, and fluidic membranes enabled accelerated reaction kinetics. Our MOHCR system demonstrated high efficiency and accuracy in differentiating between plasma samples from breast cancer patients and healthy donors.


Asunto(s)
Técnicas Biosensibles , Exosomas , Neoplasias , Humanos , Exosomas/química , Cinética , Hibridación de Ácido Nucleico , Proteínas/análisis , Técnicas Biosensibles/métodos
11.
Disaster Med Public Health Prep ; 17: e302, 2022 11 03.
Artículo en Inglés | MEDLINE | ID: mdl-36325834

RESUMEN

OBJECTIVE: This study aimed to investigate the nurse-patient trust among in-patients in the context of the coronavirus disease (COVID-19) epidemic; it further analyzed the related influencing factors, which will provide a theoretical basis for developing corresponding measures. METHODS: This study employed a mixed-method design and analyzed 149 patients at the Hongqi Hospital, affiliated with Mudanjiang Medical University, from December 2020 to February 2021. Quantitative analysis was carried out using the "Nurse Patient Trust Scale," and qualitative analysis was performed using a semi-structured interview with in-patients. RESULTS: The average score on the scale was 46.65 ± 2.83, and the scores of the 2 dimensions were: 23.24 ± 1.51 for ability and peace of mind, and 23.32 ± 1.53 for attitude and care. According to the interview data, the factors included 3 aspects: a comfortable hospital environment and humane management measures; the nurse's own competence; and effective communication with patients. CONCLUSION: During the COVID-19 epidemic, there are still many factors affecting patients' trust in nurses that can be addressed by taking different measures. All these factors must be considered by the relevant managers and clinical nursing staff to maintain a better nurse-patient trust relationship.


Asunto(s)
COVID-19 , Enfermeras y Enfermeros , Personal de Enfermería en Hospital , Humanos , Confianza , Pandemias , COVID-19/epidemiología , Pacientes
12.
Exp Eye Res ; 225: 109275, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36206860

RESUMEN

Members of the microRNA-29 (miR-29) gene family have been implicated as suppressors of collagen in several human diseases. The present study aimed to explore the function of miR-29a in human fetal scleral fibroblasts (HFSFs) and to investigate potential mechanisms by which the molecule regulates cellular functioning. First, HFSFs were transfected with miR-29a mimic, miR-29a inhibitor, or their corresponding controls. Then, cell proliferation and apoptosis were assessed using a CCK-8 assay and flow cytometry, respectively. Further, using real-time PCR, western blotting, and immunofluorescence staining, levels of miR-29a, heat shock protein 47 (Hsp47), COL1A1, Smad3, P-Smad3, Bax, and Bcl-2 were investigated. Next, empty vectors and SERPINH1-overexpressing vectors were used to transfect HFSFs. Western blotting and flow cytometry were performed to assess changes in levels of HFSF protein expression and apoptosis, respectively. Results indicated that the miR-29a mimic significantly inhibited Hsp47, Smad3, P-Smad3, and COL1A1 expression. Conversely, the miR-29a inhibitor enhanced the expression of the same genes. Furthermore, miR-29a overexpression inhibited HFSFs proliferation and enhanced the rate of HFSFs apoptosis. Consistent with this finding, miR-29a overexpression led to the downregulation of Bcl-2 and upregulation of Bax. In contrast, miR-29a suppression led to the upregulation of Bcl-2 and downregulation of Bax expression and reduced the rate of apoptosis. Additional research revealed that overexpression of Hsp47 prevented HFSFs apoptosis and enhanced collagen production. Findings that miR-29a overexpression reduces collagen expression levels, slows proliferation, and promotes apoptosis in HFSFs highlight the key role of miR-29a in scleral remodeling. The effects of miR-29a on scleral remodeling might mediate by targeting Hsp47 and repressing the Smad3 pathway.


Asunto(s)
Proteínas del Choque Térmico HSP47 , MicroARNs , Humanos , Proteínas del Choque Térmico HSP47/genética , Proteínas del Choque Térmico HSP47/metabolismo , Proteína X Asociada a bcl-2/metabolismo , MicroARNs/metabolismo , Apoptosis/genética , Fibroblastos/metabolismo , Proliferación Celular , Transducción de Señal , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Colágeno/metabolismo , Proteína smad3/genética , Proteína smad3/metabolismo
13.
Cureus ; 14(4): e24494, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35651393

RESUMEN

Meckel's diverticulum (MD) is a well-known gastrointestinal (GI) congenital anomaly that is generally considered a disorder in neonates or a "clinically silent" disorder in adults. While prevalent in children, MD is not often considered as a differential in the etiology of GI bleeding in the adult population. We describe a case of MD presenting as a copious GI bleed in a 65-year-old male, which was found after numerous diagnostic studies. Our case report aims to challenge the idea that Meckel's diverticulum is solely a neonatal disorder, identify this vitelline duct remnant as a potential cause of GI pathology in the adult population, and discuss the detection and management of this congenital abnormality when found in the older population.

14.
Case Rep Gastroenterol ; 16(3): 675-679, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36605729

RESUMEN

Our patient is a 47-year-old African American female with a past medical history of recurrent episodes of small bowel obstruction. She presented to the emergency department with symptoms of nausea, vomiting, and abdominal pain. Upon further evaluation, imaging showed obstruction at the terminal ileum. Based on the holistic clinical presentation, we initially thought that this patient was experiencing symptoms of early onset Crohn's disease. Gastroenterology evaluated the patient and was uncertain of the formal diagnosis. Colonoscopy and biopsy were not pathognomonic for Crohn's disease, suggesting that there may be a component of terminal ileitis or another inflammatory bowel disease process. This case exemplifies the degree to which these inflammatory bowel disease processes frequently overlap.

15.
Wound Repair Regen ; 30(1): 34-44, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34826355

RESUMEN

Wound healing may be disrupted by lipopolysaccharide (LPS)-induced mitochondrial dysfunction, inflammation, and excessive oxidative stress, which can lead to undesirable consequences. The haematopoietic cell-specific protein 1-associated protein X-1 (HAX-1) is a mitochondrial matrix protein that regulates mitochondrial function. This study aimed to comprehensively identify the role of HAX-1 in the inhibition of LPS-induced mitochondrial dysfunction and apoptosis in human dermal fibroblasts (HDFs). HAX-1 expression was assessed in the HDF-a cell line using real-time polymerase chain reaction, western blotting, and immunohistochemical staining. The viability, migration, and apoptosis of HDF-a cells were evaluated using the water-soluble tetrazolium-1 assay, transwell assay, and flow cytometry analysis, respectively. Mitochondrial function was evaluated based on reactive oxygen species (ROS) generation and mitochondrial membrane potential (ΔΨm). Our results demonstrated that LPS stimulation markedly repressed HAX-1 expression in HDFs and silencing of HAX-1 led to mitochondrial ROS accumulation, ΔΨm disruption, and abnormal mitochondrial morphology. Accordingly, overexpression of HAX-1 or administration of metformin enhanced mitochondrial fusion and normalized mitochondrial dynamics, thereby reversing LPS-induced mitochondrial dysfunction, fibroblast apoptosis, and viability and migration inhibition in HDF-a cells. These data support a mechanism wherein HAX-1 plays a crucial role in LPS-induced fibroblast apoptosis in a mitochondria-dependent manner.


Asunto(s)
Lipopolisacáridos , Cicatrización de Heridas , Apoptosis , Fibroblastos , Humanos , Lipopolisacáridos/farmacología , Especies Reactivas de Oxígeno
16.
Cureus ; 14(12): e32293, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36628017

RESUMEN

The presentation of Burkitt lymphoma (BL) is variable and highly dependent on its subtype. It often presents with non-specific symptoms and may appear in the jaw, bone marrow, liver, spleen, kidneys, ovaries, and gastrointestinal tract. This case describes a 50-year-old male who presented with abdominal pain and was eventually found to have Burkitt lymphoma, diagnosed by biopsy of a cecal polyp. Herein, we explore the diagnostic journey to BL and review the literature regarding its unique manifestations and thus the diagnostic challenge it can present.

17.
Appl Radiat Isot ; 168: 109530, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33285464

RESUMEN

N-(2-18F-fluoropropionyl)-l-glutamate (18F-FPGLU), a new N-substituted 18F-labeling l-glutamate, is a potential amino acid tracer for oncology PET imaging with good tumor-to-background contrast in several tumor-bearing mice. Herein, we evaluated the potential value of 18F-FPGLU for PET imaging of glioma in orthotopic glioma-bearing SD rats. A series of competitive inhibition experiments with various types of inhibitors were conducted with C6 cells to investigate the transport mechanism of 18F-FPGLU in glioma. Establishment of orthotopic rat C6 glioma-bearing SD rats models was confirmed by MRI. Then PET imaging of 18F-FPGLU was performed on the orthotopic C6 glioma-bearing SD rats and compared with that of 18F-FDG. After the rats sacrificed, the whole brain was collected and immunofluorescence staining of glial fibrillary acidic protein (GFAP) and matrix metalloproteinase 2 (MMP2) were processed. Na+-dependent system XAG- and Na+-independent system XC- are the mainly transporters of 18F-FPGLU in C6 cells. N-methyl-d-aspartate (NMDA) receptor, which is associated with the invasiveness and proliferation of glioma cells, is also involved in the uptake of 18F-FPGLU. High uptake and retention of 18F-FPGLU was observerd in orthotopic glioma with good visualization and the tumor/background ratio reached 2.35 at 60 min post-injection, which was significantly higher than that of 18F-FDG (1.72) in small-animal PET images. High expression of MMP-2 and GFAP was observed in the immunofluorescence staining of glioma xerography slices. 18F-FPGLU seems to be a better potential PET tracer than 18F-FDG for brain glioma imaging with good visualization and ability to assess the tumor activity.


Asunto(s)
Encéfalo/diagnóstico por imagen , Radioisótopos de Flúor/química , Glioma/diagnóstico por imagen , Glutamatos/química , Tomografía de Emisión de Positrones/métodos , Radiofármacos/química , Animales , Línea Celular Tumoral , Técnica del Anticuerpo Fluorescente , Glutamatos/farmacocinética , Xenoinjertos , Imagen por Resonancia Magnética/métodos , Ratas , Ratas Sprague-Dawley
18.
Transl Vis Sci Technol ; 9(13): 18, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-33344062

RESUMEN

Purpose: To investigate the roles of motion perception and visual acuity in driving hazard detection. Methods: Detection of driving hazard was tested based on video and still-frames of real-world road scenes. In the experiment using videos, 20 normally sighted participants were tested under four conditions: with or without motion interruption by interframe mask, and with or without simulated low visual acuity (20/120 on average) by using a diffusing filter. Videos were down-sampled to 2.5 Hz, to allow the addition of motion interrupting masks between the frames to maintain video durations. In addition, single still frames extracted from the videos were shown in random order to eight normally sighted participants, who judged whether the frames were during ongoing hazards, with or without the diffuser. Sensitivity index d-prime (d') was compared between unmasked motion (n = 20) and still frame conditions (n = 8). Results: In the experiment using videos, there was a significant reduction in a combined performance score (taking account of reaction time and detection rate) when the motion was disrupted (P = 0.016). The diffuser did not affect the scores (P = 0.419). The score reduction was mostly due to a decrease in the detection rate (P = 0.002), not the response time (P = 0.148). The d' of participants significantly decreased (P < 0.001) from 2.24 with unmasked videos to 0.68 with still frames. Low visual acuity also had a significant effect on the d' (P = 0.004), but the change was relatively small, from 2.03 without to 1.56 with the diffuser. Conclusions: Motion perception plays a more important role than visual acuity for detecting driving hazards. Translational Relevance: Motion perception may be a relevant criterion for fitness to drive.


Asunto(s)
Conducción de Automóvil , Percepción de Movimiento , Humanos , Tiempo de Reacción , Visión Ocular , Agudeza Visual
19.
Transl Vis Sci Technol ; 9(4): 26, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-32818113

RESUMEN

Purpose: In most states, people with reduced visual acuity may legally drive with the aid of a bioptic telescope. However, concerns have been raised that the ring scotoma may impair detection of peripheral hazards. Using a driving simulator, we tested the hypothesis that the fellow eye would be able to compensate for the ring scotoma when using a monocular telescope. Methods: Sixteen bioptic users completed three drives with binocular viewing interleaved between three drives with monocular viewing. Forty pedestrians appeared and ran on the road for 1 second, including 26 within the ring scotoma, while participants were reading road signs through their own monocular telescopes. Head movements were analyzed to determine whether the pedestrian appeared before or only while using the telescope. Results: For pedestrians that appeared only during bioptic use and were likely in the area of the ring scotoma, detection rates were significantly higher in binocular (fellow eye can compensate) than monocular (fellow eye patched) viewing (69% vs. 32%; P < 0.001); this was true for both current and noncurrent drivers. For pedestrians appearing before or after bioptic use, detection rates did not differ in binocular and monocular viewing. However, detection rates were even higher and reaction times shorter when the telescope was not being used. Conclusions: Both current and noncurrent drivers'  fellow eyes were able to compensate, at least in part, for the ring scotoma. Translational Relevance: When using monocular telescopes, the fellow eye reduces the impact of the ring scotoma on hazard detection in binocular viewing.


Asunto(s)
Conducción de Automóvil , Telescopios , Baja Visión , Anteojos , Humanos , Escotoma
20.
RSC Adv ; 10(38): 22606-22615, 2020 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-35514601

RESUMEN

Hierarchical Co(OH)2@NiMoS4 nanocomposites were successfully prepared on a carbon cloth by using a simple two-step hydrothermal method coupled with a room-temperature vulcanization method. The resulting nanocomposites were composed of large-scale uniform Co(OH)2 nanowires fully covered with ultrathin vertical NiMoS4 nanoflakes. Because of the synergetic effect between Co(OH)2 and NiMoS4, the nanocomposites exhibited good electrochemical performance as a supercapacitor electrode. In particular, a specific capacity of 2229 F g-1 was achieved at a current density of 1 A g-1. In addition, an asymmetrical supercapacitor fabricated using activated carbon as the negative electrode and the as-synthesised nanocomposite as the positive electrode exhibited a maximum energy density of 59.5 W h kg-1 at a power density of 1 kW h kg-1 and excellent cycling stability (100% capacitance retention after 5000 cycles). These results indicate that the hierarchical Co(OH)2@NiMoS4 nanocomposite has great potential for practical application in high-performance energy storage devices.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...