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1.
Marit Policy Manag ; 51(3): 484-502, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38832094

RESUMEN

Recent maritime cybersecurity accidents reveal that shipping is facing increased exposure to cyber threats, especially due to the fast-growing digitalisation of the sector, leaving vessels and their onboard systems vulnerable to cyberattacks. This research aims at evaluating the relationship among the critical dimensions influencing cybersecurity performance in the maritime industry. To achieve this, six critical dimensions related to cybersecurity preparedness are first identified through literature review, namely 'regulations', 'company procedures' from a managerial perspective and 'shipboard systems readiness', 'training and awareness', 'human factor' and 'compliance monitoring' at an operation level. A Likert-scale questionnaire is designed and used to collect empirical data from 133 seafarers and shore-based staff. Structural Equation Modelling (SEM) is applied to examine the causal relationships between the six dimensions and shipboard cybersecurity performance. The results show that 'regulations' positively influence shipping companies' cybersecurity-related 'procedures', which in turn positively affects 'shipboard systems readiness', 'training and awareness', and 'monitoring'. Further, 'training and awareness' positively influences the cybersecurity performance of ships. The results have profound implications for the shipping industry on how to strengthen their cyber practices in order to improve their cybersecurity performance. Recommendations for future academic research related to maritime cybersecurity are also provided.

2.
Nano Lett ; 24(5): 1808-1815, 2024 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-38198566

RESUMEN

The novel depth-sensing system presented here revolutionizes structured light (SL) technology by employing metasurfaces and photonic crystal surface-emitting lasers (PCSELs) for efficient facial recognition in monocular depth-sensing. Unlike conventional dot projectors relying on diffractive optical elements (DOEs) and collimators, our system projects approximately 45,700 infrared dots from a compact 297-µm-dimention metasurface, drastically more spots (1.43 times) and smaller (233 times) than the DOE-based dot projector in an iPhone. With a measured field-of-view (FOV) of 158° and a 0.611° dot sampling angle, the system is lens-free and lightweight and boasts lower power consumption than vertical-cavity surface-emitting laser (VCSEL) arrays, resulting in a 5-10 times reduction in power. Utilizing a GaAs-based metasurface and a simplified optical architecture, this innovation not only addresses the drawbacks of traditional SL depth-sensing but also opens avenues for compact integration into wearable devices, offering remarkable advantages in size, power efficiency, and potential for widespread adoption.

3.
Discov Nano ; 18(1): 149, 2023 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-38062340

RESUMEN

Free-space optical communications hold promising advantages, including a large bandwidth, access to license-free spectrum, high data rates, quick and simple deployment, low power consumption, and relaxed quality requirements. Nevertheless, key technical challenges remain, such as a higher transmission efficiency, a lower transmission loss, and a smaller form factor of optical systems. Here, we demonstrate the viability of circular-polarization-multiplexed multi-channel optical communication using metasurfaces alongside a photonic-crystal surface-emitting laser (PCSEL) light source at wavelength of 940 nm. Through the light manipulation with metasurface, we split the linearly polarized incidence into left and right circular polarizations with desired diffraction angles. Such orthogonal polarization states provide a paradigm of polarization division multiplexing technique for light communication. The PCSEL light source maintains a low divergence angle of about 0.373 degrees after passing through an ultra-thin metasurface without further bulky collimator or light guide, making end-to-end (E2E) and device-to-device (D2D) communications available in a compact form. Both light source and modulated polarized light exhibit a - 3 dB bandwidth over 500 MHz, with successful 1 Gbit/s transmission demonstrated in eye diagrams. Our results affirm that metasurface effectively boosts transmission capacity without compromising the light source's inherent properties. Future metasurface designs could expand channel capacity, and its integration with PCSEL monolithically holds promise for reducing interface losses, thereby enhancing efficiency.

4.
Discov Nano ; 18(1): 87, 2023 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-37382858

RESUMEN

Metasurfaces, a catalog of optical components, offer numerous novel functions on demand. They have been integrated with vertical cavity surface-emitting lasers (VCSELs) in previous studies. However, the performance has been limited by the features of the VCSELs such as low output power and large divergence angle. Although the solution of the module of VCSEL array could solve these issues, the practical application is limited by extra lens and large size. In this study, we experimentally demonstrate reconstruction of a holographic images using a compact integration of a photonic crystal surface-emitting laser and metasurface holograms designed for structured light generation. This research showcases the flexible design capabilities of metasurfaces, high output power (on the order of milliwatts), and the ability to produce well-uniformed images with a wide field of view without the need for a collection lens, making it suitable for 3D imaging and sensing.

5.
Clin Toxicol (Phila) ; 60(4): 446-450, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-34543159

RESUMEN

CONTEXT: Mortality prediction in paraquat poisoning is a major issue since most prediction rules are inapplicable if the exact ingestion time cannot be determined and/or the serum paraquat concentration is not readily available, as in most countries. Therefore, we aimed to develop and validate a new prediction rule not requiring these two parameters. METHODS: We designed a 10-year observational cohort study including all consecutive paraquat-poisoned patients managed in two Taiwanese hospitals. We built one cohort to define and one cohort to validate this prediction rule. Parameters independently related to mortality determined using a multivariate analysis were used to formulate the Acute Paraquat Poisoning Mortality (APPM) score. RESULTS: Overall, 321 paraquat-poisoned patients were included, 156 in the derivation and 165 in the validation cohort. Mortality rates in the derivation and validation cohorts were 73% and 81%, respectively (p = 0.20). The three parameters chosen of 28-day mortality at presentation were urine paraquat level >10 ppm (using a colorimetric sodium dithionite-based test; odds ratio (OR), 12.70; 95% confidence interval (CI), 2.64-61.24), white blood cells >13.0 G/L (OR, 5.50; CI, 1.41-21.48) and blood glucose >140 mg/dL [7.8 mmol/L] (OR, 7.45; CI, 1.70-32.86). In the derivation cohort, the area under the ROC curve (AUC-ROC) of the APPM score did not significantly differ from AUC-ROCs of serum paraquat (0.95, p = 0.25) and the Severity Index of Paraquat Poisoning (0.95, p = 0.33). AUC-ROCs of the APPM score in the derivation and validation cohorts were 0.91 and 0.94, respectively. CONCLUSION: We built and validated a reliable score to predict 28-day mortality in paraquat-poisoned patients at presentation, independently from the ingestion time and serum paraquat measurement.


Asunto(s)
Intoxicación , Venenos , Área Bajo la Curva , Humanos , Paraquat , Intoxicación/diagnóstico , Pronóstico , Estudios Retrospectivos
6.
Basic Clin Pharmacol Toxicol ; 129(6): 496-503, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34478614

RESUMEN

Paraquat is responsible for an extremely high case-fatality rate poisoning. Mortality prediction remains a major issue since evidence to support benefits of routinely used treatments is lacking. We aimed to develop an easy-to-use prediction flowchart not requiring the ingestion time, for which accuracy is frequently questionable, and to evaluate the effectiveness of routinely used pharmacological therapies on mortality. We designed a two-centre cohort study including consecutive paraquat-poisoned adults with confirmed diagnosis based on serum/urine paraquat measurement. We built a flowchart using a multivariate analysis of death predictors and analysed the outcome according to the administered therapies. Overall, 256 patients were enrolled. Mortality rate was 75%. Independent death predictors on admission were serum creatinine (odds ratio [OR], 5.07; 95% confidence interval [CI], 1.97-13.05) and serum paraquat concentration (OR, 2.26; CI, 1.66-3.09). The area-under-the flowchart curve was 0.91. Overall sensitivity and specificity were 81.5% and 94.8%, respectively. More survivors than non-survivors of severe poisoning received methylprednisolone (P = 0.04). While not significantly differing in severity, methylprednisolone-treated patients had better survival (P = 0.04). To conclude, we defined an efficient flowchart to predict mortality in paraquat poisoning at presentation, even if ingestion time is undetermined. Methylprednisolone seems effective to improve the outcome, especially in the most severe cases.


Asunto(s)
Metilprednisolona/administración & dosificación , Paraquat/envenenamiento , Intoxicación/mortalidad , Diseño de Software , Adulto , Anciano , Estudios de Cohortes , Femenino , Glucocorticoides/administración & dosificación , Herbicidas/envenenamiento , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Intoxicación/tratamiento farmacológico , Estudios Retrospectivos , Sensibilidad y Especificidad , Índice de Severidad de la Enfermedad , Tasa de Supervivencia
7.
Artículo en Inglés | MEDLINE | ID: mdl-33540581

RESUMEN

This study aimed to determine whether daily physical activity in young and older adults with T2DM is associated with diabetes control. A prospective correlational study involving 206 young (≤65 years) and older (>65 years) adults was conducted. The International Physical Activity Questionnaire was used to assess their daily physical activity levels. Patients' mean HbA1c level was 7.8% (±1.4), and 95.9% of patients had unsatisfactory diabetes control. Performing more minutes per week of moderate-intensity daily physical activity was associated with a lower risk of glycemia in both young and older adults. Furthermore, moderate daily physical activity significantly lowered the risk of glycemia. Health personnel must encourage patients to engage in moderate daily physical activities to improve diabetes control.


Asunto(s)
Diabetes Mellitus Tipo 2 , Anciano , Glucemia , Diabetes Mellitus Tipo 2/epidemiología , Diabetes Mellitus Tipo 2/prevención & control , Ejercicio Físico , Humanos , Estudios Longitudinales , Estudios Prospectivos
8.
J Acute Med ; 10(1): 27-39, 2020 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-32995152

RESUMEN

BACKGROUND: Epistaxis is the most common cause of otorhinolaryngologic emergencies. There is a longstanding controversy regarding the relationship between epistaxis and hypertension (HTN), in terms of blood pressure (BP) control in the emergency department (ED) setting. The objective of this study is to evaluate the association between HTN, BP control, and recurrent epistaxis among patients initially admitted to the ED for epistaxis. METHODS: This retrospective cohort study was conducted in the EDs of three different hospitals in Taiwan and included a total of 739 patients admitted for epistaxis. RESULTS: Among ED patients with epistaxis, older age was significantly associated with a history of HTN, and a statistically significant difference in age was noted between groups classified according to the systolic BP/diastolic BP (SBP/DBP) at triage. Patients with a history of HTN had higher BP values at triage than did patients without a history of HTN (SBP: 175.68 ± 32.30 mmHg vs. 148.00 ± 26.26 mmHg, DBP: 95.04 ± 20.98 mmHg vs. 83.30 ± 16.65 mmHg; p < 0.0001). Antihypertensive medications were more commonly administered to patients with a history of HTN (p < 0.0001) and in those patients with SBP/DBP: ≥ 140/≥ 90 mmHg at triage (p < 0.0001). Among patients receiving antihypertensive medications, reductions in SBP by the time of discharge were significantly greater in patients with a history of HTN and in patients with SBP/DBP: ≥ 160/≥ 100 mmHg at triage. ED revisits due to recurrent epistaxis within 72 hours were significantly associated with male sex, a positive history of HTN, level of GOT, observation for recurrent epistaxis at ED, and duration of recurrent bleeding. CONCLUSIONS: A positive history of HTN is related to recurrent epistaxis among ED patients. The effectiveness of administering antihypertensive agents before achieving hemostasis in patients admitted to the ED for epistaxis warrants further study.

9.
Biomed Res Int ; 2016: 2414809, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27366739

RESUMEN

Modification of the physiochemical properties of titanium surfaces using glow discharge plasma (GDP) and fibronectin coating has been shown to enhance the surface hydrophilicity, surface roughness, cell adhesion, migration, and proliferation. This in vivo study aimed to evaluate the bone integration efficacy of a biologically modified implant surface. Two different surface-modified implants (Ar-GDP and GDP-fib) were placed in the mandibular premolar area of six beagle dogs for 2-8 weeks. Three techniques [histologic evaluation, resonance frequency analysis (RFA), and microcomputed tomography (micro-CT) evaluation] were used to detect the implant stability and bone-implant contact. The implant stability quotient values of GDP-fib implants were significantly greater than the Ar-GDP implants at 2 and 4 weeks (P < 0.01). The bone volume/total volume ratio of GDP-fib implants was greater than the Ar-GDP implants in micro-CT evaluation. A high positive correlation was observed between RFA and micro-CT measurements. At 2 weeks, osteoblasts were seen to line the implant surface, and multinuclear osteoclasts could be seen on the surface of old parent bone. After 8 weeks, a majority of the space in the wound chamber appeared to be replaced by bone. Enhancement of the stability of biologically modified implants was proved by the results of RFA, micro-CT, and histological analysis. This enhanced stability may help fasten treatment and be clinically beneficial.


Asunto(s)
Interfase Hueso-Implante/diagnóstico por imagen , Materiales Biocompatibles Revestidos/química , Implantes Dentales , Fibronectinas/química , Titanio/química , Microtomografía por Rayos X , Animales , Perros
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