Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
1.
Ergonomics ; : 1-14, 2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-38037382

RESUMEN

This study analyzes 4,095 proactive safety inspection records obtained from a large dispatching centre by utilising the HFACS framework. These proactive safety inspection records offer comprehensive documentation of incidents, capturing major accidents and numerous minor discrepancies and lapses that often go unnoticed in accident reports. The analysis revealed that most incidents were attributed to unsafe actions, primarily skill-based errors and poor decision-making. Additionally, contributing factors such as adverse mental states, personal readiness, and crew resource management were found to play a significant role as preconditions for unsafe acts. Path analyses further established a significant correlation between factors such as unsafe supervision, preconditions for unsafe acts, and the occurrence of unsafe acts. In our discussion, we critically evaluate the strengths and limitations of proactive safety inspection records in safety research. Moreover, we emphasise these findings' potential to enhance safety within the railway industry.


Based on a substantial dataset comprising proactive safety inspection records of railway dispatchers rather than the incident reports utilised in prior studies, this paper presents a causal model of human error among railway dispatchers in combination with HFACS and critically evaluates the strengths and limitations of active safety inspection records.

2.
J Org Chem ; 86(6): 4763-4778, 2021 03 19.
Artículo en Inglés | MEDLINE | ID: mdl-33689328

RESUMEN

Glycosidation plays a pivotal role in the synthesis of O-glycosides and nucleosides that mediate a diverse range of biological processes. However, efficient glycosidation approach for the synthesis of both O-glycosides and nucleosides remains challenging in terms of glycosidation yields, mild reaction conditions, readily available glycosyl donors, and cheap promoters. Here, we report a versatile N-iodosuccinimide/trimethylsilyl triflate (NIS/TMSOTf)-promoted glycosidation approach with glycosyl ortho-hexynylbenzoates as donors for the highly efficient synthesis of O-glycosides and nucleosides. The glycosidation approach highlights the merits of mild reaction conditions, cheap promoters, extremely wide substrate scope, and good to excellent yields. Notably, the glycosidation approach performs very well in the construction of a series of challenging O- and N-glycosidic linkages. The glycosidation approach is then applied to the efficient synthesis of oligosaccharides via the one-pot strategy and the stepwise strategy. On the basis of the isolation and characterization of the departure species derived from the leaving group, a plausible mechanism of NIS/TMSOTf-promoted glycosidation of glycosyl ortho-hexynylbenzoates is proposed.


Asunto(s)
Glicósidos , Nucleósidos , Glicosilación , Oligosacáridos , Succinimidas
3.
J Org Chem ; 84(21): 14141-14150, 2019 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-31565928

RESUMEN

A new gold(I)-catalyzed rearrangement reaction with glycosyl alkynoic ß-ketoesters as substrates is developed. The rearrangement reactions under the catalysis of PPh3AuOTf proceeded smoothly to afford a range of 4-O-glycosylated 2-pyrones. Based on the isolation of the 4-hydroxy-2-pyrone derivative generated from the departure of the leaving group and the competitive reaction, a plausible mechanism of the gold(I)-catalyzed intermolecular rearrangement reactions is proposed.

4.
Org Biomol Chem ; 17(27): 6580-6584, 2019 07 21.
Artículo en Inglés | MEDLINE | ID: mdl-31241111

RESUMEN

A gold(i)-promoted α-selective sialylation approach with 5-N,4-O-oxazolidinone-protected sialyl ortho-hexynylbenzoates as donors is described for the stereoselective synthesis of α-sialosides. Iterative couplings of the 'active' sialyl ortho-hexynylbenzoates and the 'latent' sialyl ortho-iodobenzoates provide a new approach for the 'latent-active' synthesis of α-(2 → 9)-linked oligosialic acids that are relevant to N. meningitidis serogroup C capsular polysaccharide.

5.
Artículo en Inglés | MEDLINE | ID: mdl-38551829

RESUMEN

The advances in AI-enabled techniques have accelerated the creation and automation of visualizations in the past decade. However, presenting visualizations in a descriptive and generative format remains a challenge. Moreover, current visualization embedding methods focus on standalone visualizations, neglecting the importance of contextual information for multi-view visualizations. To address this issue, we propose a new representation model, Chart2Vec, to learn a universal embedding of visualizations with context-aware information. Chart2Vec aims to support a wide range of downstream visualization tasks such as recommendation and storytelling. Our model considers both structural and semantic information of visualizations in declarative specifications. To enhance the context-aware capability, Chart2Vec employs multi-task learning on both supervised and unsupervised tasks concerning the cooccurrence of visualizations. We evaluate our method through an ablation study, a user study, and a quantitative comparison. The results verified the consistency of our embedding method with human cognition and showed its advantages over existing methods.

6.
Artículo en Inglés | MEDLINE | ID: mdl-37030780

RESUMEN

In recent years, narrative visualization has gained much attention. Researchers have proposed different design spaces for various narrative visualization genres and scenarios to facilitate the creation process. As users' needs grow and automation technologies advance, increasingly more tools have been designed and developed. In this study, we summarized six genres of narrative visualization (annotated charts, infographics, timelines & storylines, data comics, scrollytelling & slideshow, and data videos) based on previous research and four types of tools (design spaces, authoring tools, ML/AI-supported tools and ML/AI-generator tools) based on the intelligence and automation level of the tools. We surveyed 105 papers and tools to study how automation can progressively engage in visualization design and narrative processes to help users easily create narrative visualizations. This research aims to provide an overview of current research and development in the automation involvement of narrative visualization tools. We discuss key research problems in each category and suggest new opportunities to encourage further research in the related domain.

7.
Biomed Pharmacother ; 163: 114859, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37167722

RESUMEN

Uropathogenic Escherichia coli (UPEC) is the main pathogen of recurrent urinary tract infections (RUTIs). Urinary tract infection is a complicated interaction between UPEC and the host. During infection, UPEC can evade the host's immune response and retain in bladder epithelial cells, which requires adequate nutritional support. Iron is the first necessary trace element in life and a key nutritional factor, making it an important part of the competition between UPEC and the host. On the one hand, UPEC grabs iron to satisfy its reproduction, on the other hand, the host relies on iron to build nutritional immunity defenses against UPEC. Ferritinophagy is a selective autophagy of ferritin mediated by nuclear receptor coactivator 4, which is not only a way for the host to regulate iron metabolism to maintain iron homeostasis, but also a key point of competition between the host and UPEC. Although recent studies have confirmed the role of ferritinophagy in the progression of many diseases, the mechanism of potential interactions between ferritinophagy in UPEC and the host is poorly understood. In this paper, we reviewed the potential mechanisms of ferritinophagy-mediated iron competition in the UPEC-host interactions. This competitive relationship, like a tug-of-war, is a confrontation between the capability of UPEC to capture iron and the host's nutritional immunity defense, which could be the trigger for RUTIs. Therefore, understanding ferritinophagy-mediated iron competition may provide new strategies for exploring effective antibiotic alternative therapies to prevent and treat RUTIs.


Asunto(s)
Infecciones por Escherichia coli , Infecciones Urinarias , Escherichia coli Uropatógena , Humanos , Hierro/metabolismo , Escherichia coli Uropatógena/metabolismo , Infecciones por Escherichia coli/tratamiento farmacológico
8.
IEEE Trans Vis Comput Graph ; 28(1): 206-216, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34587044

RESUMEN

Despite the rising popularity of automated visualization tools, existing systems tend to provide direct results which do not always fit the input data or meet visualization requirements. Therefore, additional specification adjustments are still required in real-world use cases. However, manual adjustments are difficult since most users do not necessarily possess adequate skills or visualization knowledge. Even experienced users might create imperfect visualizations that involve chart construction errors. We present a framework, VizLinter, to help users detect flaws and rectify already-built but defective visualizations. The framework consists of two components, (1) a visualization linter, which applies well-recognized principles to inspect the legitimacy of rendered visualizations, and (2) a visualization fixer, which automatically corrects the detected violations according to the linter. We implement the framework into an online editor prototype based on Vega-Lite specifications. To further evaluate the system, we conduct an in-lab user study. The results prove its effectiveness and efficiency in identifying and fixing errors for data visualizations.

9.
Bioresour Technol ; 319: 124110, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32977091

RESUMEN

To overcome the high biotoxicity and poor biodegradability of pyridine and its derivatives, a pre-electrochemical treatment combined with fixed bed biofilm reactor (EC-FBBR) was designed for multi-component stream including pyridine (Pyr), 3-cyanopyridine (3-CNPyr), and 3-chloropyridine (3-ClPyr). The EC-FBBR system could simultaneously degrade these pollutants with a mineralization efficiency of 90%, especially for the persistent 3-ClPyr. Specifically, the EC could partially degrade all pollutants, and allow them to be completely destructed in FBBR. With EC off, Rhodococcus (35.5%) became the most abundant genus in biofilm, probably due to its high tolerance to 3-ClPyr. With EC on, 3-ClPyr was reduced to an acceptable level, thus Paracoccus (21.1%) outcompeted among interspecies competition with Rhodococcus and became the dominant genus. Paracoccus was considered to participate in the subsequent degradation for the residual 3-ClPyr, and led to the complete destruction for all pollutants. This study proposed promising combination for effective treatment of multi-component pyridine wastewater.


Asunto(s)
Microbiota , Aguas Residuales , Biopelículas , Reactores Biológicos , Piridinas , Eliminación de Residuos Líquidos
10.
Org Lett ; 21(23): 9693-9698, 2019 12 06.
Artículo en Inglés | MEDLINE | ID: mdl-31746617

RESUMEN

A simple and versatile glycosylation method with both armed and disarmed glycosyl ynenoates as donors is developed. Employing a gold(I) complex as catalyst with or without the assistance of TfOH, the scope of the present glycosylation protocol is very wide. The utility of the present ynenoate donors is demonstrated in the efficient synthesis of oligosaccharides via the latent-active strategy and the multiple orthogonal one-pot strategy. Finally, this approach enables the formal synthesis of the tetrasaccharide hapten of Streptococcus pneumoniae serotype 3 and the highly convergent synthesis of the 32mer polymannoside.

11.
J Biomol Struct Dyn ; 36(14): 3819-3828, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29182104

RESUMEN

Ecdysone receptor (EcR) is an important target for pesticide design. Ligand binding regulates EcR transcriptional activity similar to other nuclear receptors; however, the pathways by which ligands enter and leave the EcR remain poorly understood. Here, we performed computational studies to identify unbinding pathways of an ecdysone agonist [the selective ecdysone agonist, BYI06830] from the EcR ligand binding domain (EcR LBD). BYI06830 can dissociate from EcR LBD via four different pathways with little effect on receptor structure. By comparing the potential of mean force (PMF) of four pathways, path 2 was considered to be the most likely exit path for BYI06830, which was located in the cleft formed by the H3-H4 loop, H6-H7 loop, and the H11 C-terminus. Furthermore, structural features along path 2 were analyzed and the structural snapshots of the metastable and transition states were isolated to illustrate the unbinding mechanism of ecdysone agonist from EcR LBD.


Asunto(s)
Ligandos , Conformación Molecular , Simulación de Dinámica Molecular , Receptores de Esteroides/química , Aminoácidos , Sitios de Unión , Unión Proteica , Receptores de Esteroides/metabolismo , Relación Estructura-Actividad
12.
Exp Ther Med ; 12(4): 2527-2530, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27698753

RESUMEN

The clinical effects of local application of low-dose insulin in improving wound healing after deep burn self-skin transplantation surgery were examined. Fifty-eight patients with deep burns were selected and randomly divided into 3 groups. In the blank control group, normal saline was injected to the subcutaneous tissue of wounds; in large dose insulin group, 1.0 µ long-term suspended zinc insulin was locally injected; and in the low-dose insulin group, 0.1 µ long-term suspended zinc insulin was locally injected. The healing effects were compared. After 7 and 14 days of treatments, wound surface area in the low-dose group was significantly smaller than in the other groups, and differences were statistically significant (P<0.05); wound healing duration and infection rate for patients in the low-dose group were significantly lower, class A healing rate was significantly improved, and the differences were statistically significant (P<0.05). Insulin resistance index (HOMA-IR) in the low-dose group was significantly lower, insulin secretion index (HOMA-ß) and the insulin sensitivity index (HOMA-ISI) significantly increased. The expression levels of vascular endothelial growth factor and tumor necrosis factor-α in local tissue for the low-dose group were significantly higher than those in the other two groups. Differences were statistically significant (P<0.05). In conclusion, local application of low-dose insulin can effectively improve wound healing after deep burn surgeries.

13.
Org Lett ; 17(9): 2214-7, 2015 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-25879686

RESUMEN

Vinylpyridines have been developed in aza-Morita-Baylis-Hillman (MBH) reaction to construct triarylsubstituted 3-pyrrolines. The first electron-deficient aromatic ring is marked as an activating mode for the vinyl group in the MBH reaction. This method provides efficient and rapid access to a range of triarylpyrrolines in good yields and at an excellent level of diastereoselectivity. Moreover, the synthetic potential of this protocol is further enhanced by the straightforward synthesis of unsymmetrical tri- and polyarylsubstituted pyrroles.


Asunto(s)
Fosfinas/química , Pirroles/síntesis química , Compuestos de Vinilo/química , Catálisis , Estructura Molecular , Pirroles/química , Estereoisomerismo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA