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1.
Pharmacol Res ; 187: 106632, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36572134

RESUMO

With the development of nano drug delivery system, the treatment mode that can overcome the shortcomings of chemotherapy drugs and integrate combined therapy remains to be explored. Herein, a nano drug system was designed to achieve the combined effect of chemo/chemodynamic/photodynamic therapy on cancer. Specifically, copper clusters (CuNCs) were used as the carrier, hyaluronic acid (HA) and doxorubicin (DOX) were coupled on CuNCs and then and chlorin e6 (Ce6) was introduced to form the self-assembled HA-CuNCs@DC nanoparticles. In this system, the HA-CuNCs@DC was involved in the reaction to the acidic tumor microenvironment (TME)-release of DOX, which could not only inhibit tumor growth through chemotherapy, but enhance the generation of hydrogen peroxide. CuNCs carriers had the properties of Fenton-like activity to realize chemodynamic therapy (CDT) and oxidase-like activity to deplete intracellular glutathione (GSH). Additionally, the chemotherapy drug susceptibility increased owing to the GSH depletion and the outbreak of reactive oxygen species, indicating the enhanced CDT efficacy and amplified chemotherapy efficacy. It was also noteworthy that Ce6 could be activated by 660 nm light to produce abundant singlet oxygen for photodynamic therapy. Overall, our platform demonstrated excellent biosafety and tumor suppression capabilities. This multimodal theranostic strategy provided new insights into cancer therapy.


Assuntos
Neoplasias da Mama , Fotoquimioterapia , Humanos , Feminino , Neoplasias da Mama/patologia , Cobre , Fármacos Fotossensibilizantes/uso terapêutico , Fármacos Fotossensibilizantes/farmacologia , Terapia Combinada , Doxorrubicina/farmacologia , Doxorrubicina/uso terapêutico , Microambiente Tumoral
2.
FASEB J ; 35(1): e21138, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33184932

RESUMO

Appropriate migration of cytotoxic T effector cells into the tumors is crucial for their antitumor function. Despite the controversial role of PI3K-Akt in CD8+ T cell mTORC1 activation, a link between Akt-mTORC1 signaling and CD8+ trafficking has been demonstrated. We have recently discovered that TCR-induced calcineurin activates DAPK1, which interacts with TSC2 via its death domain and phosphorylates TSC2 via its kinase domain to mediate mTORC1 activation in CD8+ T cells. However, whether DAPK1 regulates CD8+ trafficking into tumors remains unclear. Here, using pharmacological inhibitor and genetic approaches, we found that like rapamycin, inhibition of DAPK1 activity led to enhanced expression of the homing receptors CD62L and CCR7. Deletion of either kinase domain or death domain in the T cell compartment reduced the T cell activation and maintained the expression of CD62L and CCR7. DAPK1-DD-deficient mice were more susceptible to tumor growth and deficiency of DAPK1 activity significantly reduced the migratory ability of CD8+ into the tumors. These data revealed a crucial role of DAPK1-mTORC1 in mediating CD8+ trafficking and antitumor function.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Movimento Celular/imunologia , Proteínas Quinases Associadas com Morte Celular/imunologia , Imunidade Celular , Ativação Linfocitária , Neoplasias Experimentais/imunologia , Animais , Linfócitos T CD8-Positivos/patologia , Linhagem Celular Tumoral , Proteínas Quinases Associadas com Morte Celular/genética , Camundongos , Camundongos Knockout , Neoplasias Experimentais/genética , Neoplasias Experimentais/patologia
3.
AAPS PharmSciTech ; 22(1): 37, 2021 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-33409925

RESUMO

In 2017, there are 451 million people with diabetes worldwide. These figures were expected to increase to 693 million by 2045. The research and development of hypoglycemic drugs has become a top priority. Among them, sulfonylurea hypoglycemic drugs such as glipizide are commonly used in non-insulin-dependent type II diabetes. In order to adapt to the wide range of hypoglycemic drugs and the different individual needs of patients, this topic used glipizide as a model drug, and prepared glipizide preparations with 3D printing technology. The purpose of this study was to investigate the prescription applicability and control-release behavior of structure and explore the application prospects of 3D printing personalized drug delivery formulations. This article aims to establish a production process for personalized preparations based on 3D printing technology. The process is easy to obtain excipients, universal prescriptions, flexible dosages, exclusive customization, and integrated automation. In this paper, the UV method was used to determine the in vitro release and content analysis method of glipizide; the physical and chemical properties of the glipizide were investigated. The established analysis method was inspected and evaluated, and the experimental results met the methodological requirements. Glipizide controlled-release tablets were prepared by the semisolid extrusion (SSE) method using traditional pharmaceutical excipients combined with 3D printing technology. The formulation composition, in vitro release, and printing process parameters of the preparation were investigated, and the final prescription and process parameters (traveling speed 6.0-7.7 mm/s and extruding speed 0.0060-0.0077 mm/s) were selected through comprehensive analysis. The routine analysis results of the preparation showed that the performance of the preparation meets the requirements. In order for 3D printing technology to play a better role in community medicine and telemedicine, this article further explored the universality of the above prescription and determined the scope of application of prescription drugs and dosages. Glipizide, gliclazide, lornoxicam, puerarin, and theophylline were used as model drugs, and the range of drug loading percentage was investigated. The results showed when the solubility of the drug is 9.45 -8.34 mg/mL, and the drug loading is 3-43%; the release behavior is similar.


Assuntos
Formas de Dosagem , Medicina de Precisão , Impressão Tridimensional , Tecnologia Farmacêutica/métodos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Excipientes/química , Glipizida/química , Glipizida/uso terapêutico , Humanos , Hipoglicemiantes/química , Hipoglicemiantes/uso terapêutico , Solubilidade , Compostos de Sulfonilureia/química , Compostos de Sulfonilureia/uso terapêutico , Comprimidos
4.
AAPS PharmSciTech ; 21(1): 20, 2019 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-31820224

RESUMO

Thermal extrusion (TE) 3D printing is a thermoplastic semisolid-based rapid prototyping process, which is capable of building complex structures. The aim of this study was to manufacture rapid-release puerarin tablets without solvent through TE 3D printing. Novel rapid-release tablets were fabricated with polyethylene glycol (PEG 4000) as the carrier at appropriate puerarin/PEG 4000 ratios, assessed through differential scanning calorimetry (DSC), solubility, and dissolution tests. The novel structures of 3D-printed tablets with five different values were formed by printing paths, which established a flexible way of adjusting in vitro drug release. An obvious acceleration (85% of cumulative release about 7.5 min at the soonest) was observed for the tablets with internal structural design. It was inferred that puerarin formed simple eutectic mixtures with PEG 4000 and that puerarin dispersed into the carrier based on DSC and X-Ray powder diffraction (XRD). This highlights the combined advantage of PEG as a soluble polymer with TE 3D printing and provides a suitable system for rapid puerarin release.


Assuntos
Isoflavonas/química , Impressão Tridimensional , Tecnologia Farmacêutica , Liberação Controlada de Fármacos , Polietilenoglicóis/química , Solubilidade , Comprimidos/química
5.
AAPS PharmSciTech ; 20(2): 68, 2019 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-30627938

RESUMO

In the present contribution, the aim is to explore and establish a way in which 3D printing and gastro-retentive drug delivery systems (GRDDSs) are combined (focusing on inner structure innovation) to achieve extended and stable gastro-retention and controlled-release of drug. Three digital models diverse in construction were designed and substantialized by a pressure-assisted microsyringe (PAM) 3D printer. Preparations were characterized by means of DSC, XRD, FTIR, and SEM. In vitro buoyancy study and in vivo gamma scintigraphy method were conducted to validate gastro-retention property of these innovative preparations in vitro/in vivo respectively. Release kinetic model was established and release mechanism was discussed. Tablets manufactured under certain range of parameters (intersecting angle, full filling gap) were tight and accurate in shape. Tablets printed with specific parameters (full filling gap, 50%; nozzle extrusion speed, 0.006 mm/s; layer height, 0.4 mm; compensation value, 0.25; quantity of layers, 15; outline printing value, 2) exhibited satisfactory in vitro (10-12 h)/in vivo (8-10 h) retention ability and possessed stable 10-12 h controlled-release quality. In general, 3D printing has tremendous advantage over conventional fabrication technique in intricate drug delivery systems and will be widely employed in pharmacy.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Liberação Controlada de Fármacos , Derivados da Hipromelose/administração & dosagem , Impressão Tridimensional , Estômago/efeitos dos fármacos , Estômago/diagnóstico por imagem , Preparações de Ação Retardada/química , Preparações de Ação Retardada/farmacocinética , Ginkgo biloba , Humanos , Derivados da Hipromelose/química , Derivados da Hipromelose/metabolismo , Comprimidos/química , Tecnologia Farmacêutica/métodos , Tomografia Computadorizada de Emissão de Fóton Único/métodos
6.
AAPS PharmSciTech ; 20(6): 236, 2019 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-31236762

RESUMO

The objective of this study was to investigate the development of a novel puerarin gastric floating system with a concentric annular internal pattern by a 3D extrusion-based printing technique and to explore the flexibility of turning the release behavior through the design of the internal structure. The composition consisted of the conventional sustained-release pharmaceutical excipients without addition of foaming agent or light materials. First, the proper alcohol/water proportion was selected for the binding agent. The desired drug release behaviors and good floating properties were obtained either through modification of the formulation composition or adjustment of the internal structure. In vitro, the printed tablets were evaluated for drug release, mechanical properties, lag time, and floating duration time. The in vivo behaviors of the formulations were noted at certain time intervals through assessment of the radiographic pictures of healthy volunteers. The gastric retention time in the 3D-printed tablet was approximately 6 h in vivo. Results indicated these puerarin gastric floating 3D-printed tablets had great potential to achieve good gastric residence time and controlled release. Therefore, 3D extrusion-based printing appears to be appropriate for the production of oral administration systems, owing to its flexibility and the great floating ability and controlled-release capacity of its products.


Assuntos
Preparações de Ação Retardada/química , Isoflavonas/administração & dosagem , Impressão Tridimensional , Estômago , Comprimidos/administração & dosagem , Preparações de Ação Retardada/farmacocinética , Liberação Controlada de Fármacos , Excipientes/química , Humanos , Isoflavonas/farmacocinética
7.
Clin Immunol ; 192: 78-84, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29689313

RESUMO

In sepsis, the liver plays a crucial role in regulating immune responses and is also a target organ for immune-related injury. Despite the critical function of CD8+ T cells against opportunistic viral infections, the CD8 immune response in the liver during sepsis remains elusive. Here we found that Tim-3 is highly up-regulated in liver CD8+ T cells in a mouse cecal ligation and puncture model and in peripheral blood CD8+ T cells of human patients with sepsis. The expression of Tim-3 in liver CD8+ T cells displayed a bi-phasic pattern and deletion of Tim-3 led to reduction of CD8+ T cell apoptosis. Administration of α-lactose, a molecule with a similar structure to galactin-9, reduced Tim-3 expression and liver injury in sepsis. Our results demonstrate that targeting Tim-3 to boost CD8+ T cell immune response may offer an improved outcome in patients with sepsis.


Assuntos
Apoptose/efeitos dos fármacos , Linfócitos T CD8-Positivos/efeitos dos fármacos , Receptor Celular 2 do Vírus da Hepatite A/antagonistas & inibidores , Lactose/farmacologia , Fígado/efeitos dos fármacos , Sepse/imunologia , Animais , Apoptose/genética , Apoptose/imunologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Células Cultivadas , Citocinas/genética , Citocinas/imunologia , Citocinas/metabolismo , Expressão Gênica/efeitos dos fármacos , Expressão Gênica/imunologia , Hepatite/genética , Hepatite/imunologia , Hepatite/prevenção & controle , Receptor Celular 2 do Vírus da Hepatite A/genética , Receptor Celular 2 do Vírus da Hepatite A/imunologia , Humanos , Lactose/administração & dosagem , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Fígado/metabolismo , Fígado/patologia , Camundongos Endogâmicos C57BL , Sepse/genética , Sepse/metabolismo
8.
Drug Dev Ind Pharm ; 44(1): 116-124, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28956647

RESUMO

Dipyridamole (DIP), having a short biological half-life, has a narrow absorption window and is primarily absorbed in the stomach. So, the purpose of this study was to prepare controlled-release floating (CRF) tablets of dipyridamole by the dry-coated method. The influence of agents with different viscosity, hydroxypropylmethylcellulose (HPMC) and polyvinylpyrollidon K30 (PVP K30) in the core tablet and low-viscosity HPMC and PVP K30 in the coating layer on drug release, were investigated. Then, a study with a three-factor, three-level orthogonal experimental design was used to optimize the formulation of the CRF tablets. After data processing, the optimized formulation was found to be: 80 mg HPMC K4M in the core tablet, 80 mg HPMC E15 in core tablet and 40 mg PVP K30 in the coating layer. Moreover, an in vitro buoyancy study showed that the optimized formulation had an excellent floating ability and could immediately float without a lag time and this lasted more than 12 h. Furthermore, an in vivo gamma scintigraphic study showed that the gastric residence time of the CRF tablet was about 8 h.


Assuntos
Química Farmacêutica/métodos , Dipiridamol/química , Excipientes/química , Derivados da Hipromelose/química , Povidona/análogos & derivados , Povidona/química , Comprimidos/química , Preparações de Ação Retardada , Dipiridamol/farmacocinética , Meia-Vida , Comprimidos/farmacocinética , Viscosidade
9.
Drug Dev Ind Pharm ; 44(5): 829-836, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29212376

RESUMO

The aim of this study was to prepare and evaluate ion-activated in situ gel ophthalmic drug delivery system based on κ-carrageenan (KC), using acyclovir as a model drug, hydroxypropyl methylcellulose (HPMC) as the viscosity agent and hydroxypropyl-ß-cyclodextrin (HP-ß-CD) as the penetration enhancer. The two ternary phase diagrams exhibited the effect of K+ and Ca2+ on the sol-to-gel transition, which turned out that KC was more sensitive to K+. The optimal ophthalmic matrix (prepared from KC and HPMC) was optimized with in vitro drug release test. The apparent permeability coefficient of acyclovir under 2% HP-ß-CD was found to have dramatically increased (2.16-ploid) than that of conventional eye drops (p < .05). The ion-activated in situ gel based on KC significantly delayed drug release and its bioavailability could be improved in comparison with the conventional eye drops. Hence, it has the potential to be a novel kind of ocular drug delivery system.


Assuntos
2-Hidroxipropil-beta-Ciclodextrina/química , Aciclovir/química , Carragenina/química , Sistemas de Liberação de Medicamentos/métodos , Géis/química , Ácido Glucurônico/química , Soluções Oftálmicas/administração & dosagem , Disponibilidade Biológica , Córnea , Liberação Controlada de Fármacos , Derivados da Hipromelose , Soluções Oftálmicas/química , Viscosidade
10.
Adv Exp Med Biol ; 1011: 131-152, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28875488

RESUMO

T cell activation, differentiation, and function are tightly regulated by a complex network of transcription factors, epigenetic modifications, and signaling pathways of both TCR and cytokines. Over the past decade, it is increasingly clear that T cell immune responses are also regulated by their associated metabolic reprograming. Compared with relatively well-understood transcriptional regulation of T cell activation, differentiation, and function, less is known about the transcriptional regulation of T cell metabolic reprograming during T cell immune responses. In this review, we first describe how signaling pathways of TCR and cytokines regulate metabolic reprograming and then focus on transcription factors that control metabolic pathways and outcomes of T cell immune responses. A better understanding of T cell metabolic regulation will provide new strategies and targets for the treatment of T cell-related diseases.


Assuntos
Regulação da Expressão Gênica , Ativação Linfocitária , Transdução de Sinais , Linfócitos T/metabolismo , Diferenciação Celular , Reprogramação Celular , Humanos
11.
Fish Shellfish Immunol ; 54: 333-41, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27109200

RESUMO

As a member of animal lectin family, galectin has the functions of pathogen recognition, anti-bacteria and anti-virus. In the present study, a galectin-1 homolog (EcGel-1) from grouper (Epinephelus coioides) was cloned and its possible role in fish immunity was analyzed. The full length cDNA of EcGel-1 is 504 bp, including a 408 bp open reading frame (ORF) which encodes 135 amino acids with a molecular mass of 15.19 kDa. Quantitative real-time PCR analysis indicated that EcGel-1 was constitutively expressed in all analyzed tissues of healthy grouper. The expression of EcGel-1 in the spleen of grouper was differentially up-regulated challenged with Singapore grouper iridovirus (SGIV), poly (I:C), and LPS. EcGel-1 was abundantly distributed in the cytoplasm in GS cells. Recombinant EcGel-1(rEcGel-1) protein can make chicken erythrocyte aggregation, and combine with gram negative bacteria and gram positive bacteria in the presence of 2-Mercaptoethanol (ß-ME). Taken together, the results showed that EcGel-1 may be an important molecule involved in pathogen recognition and pathogen elimination in the innate immunity of grouper.


Assuntos
Bass , Infecções por Vírus de DNA/veterinária , Doenças dos Peixes/genética , Proteínas de Peixes/genética , Galectina 1/genética , Imunidade Inata , Sequência de Aminoácidos , Animais , Clonagem Molecular , Infecções por Vírus de DNA/genética , Infecções por Vírus de DNA/imunologia , Infecções por Vírus de DNA/virologia , DNA Complementar/genética , DNA Complementar/metabolismo , Doenças dos Peixes/imunologia , Doenças dos Peixes/virologia , Proteínas de Peixes/química , Proteínas de Peixes/metabolismo , Galectina 1/química , Galectina 1/metabolismo , Lipopolissacarídeos/farmacologia , Filogenia , Poli I-C/farmacologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ranavirus/fisiologia , Alinhamento de Sequência/veterinária
12.
Fish Shellfish Immunol ; 47(2): 807-16, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26476109

RESUMO

Toll-interacting protein (Tollip) is one of the important regulatory proteins of Toll-like receptor (TLR) signaling pathways. In previous studies, a Tollip sequence of grouper (Epinephelus coioides) was identified and the signal transduction functions of Tollip were studied. However, the response of Tollip to virus infection has not been characterized from grouper. In the present paper, the Tollip homolog (EtTollip) from grouper (Epinephelus tauvina) was cloned and its immune response to Singapore grouper iridovirus (SGIV) was investigated. EtTollip shares significant similarities to other mammalian Tollips, which contain a centrally localized protein kinase C conserved region 2 (C2) domain and a C-terminal CUE domain. After challenging with SGIV, the expression levels of EtTollip were altered in the spleen and head kidney of grouper. EtTollip mainly aggregated in the cytoplasm in a condensed state and was also distributed on the membranes of GS cells. EtTollip significantly inhibited the activities of NF-κB and IFN-ß luciferase reporter when transfected into grouper spleen (GS) cells. SGIV can increase the activities of NF-κB and IFN-ß luciferase reporter, especially to IFN-ß. When transfected EtTollip with EcMyd88, the activity of NF-κB was increased, while transfected EtTollip with EcIRF3, the activity of IFN-ß was significantly increased. Over-expressed EtTollip inhibited the transcription of SGIV genes significantly in GS cells, and silencing of EtTollip with siRNA led to increase of SGIV genes loads. Taken together, the results provide new insights in to the importance of Tollip as evolutionarily conserved molecule for grouper innate immunity against virus infection.


Assuntos
Bass , Infecções por Vírus de DNA/imunologia , Doenças dos Peixes/imunologia , Proteínas de Peixes/genética , Imunidade Inata , Peptídeos e Proteínas de Sinalização Intracelular/genética , Ranavirus/fisiologia , Sequência de Aminoácidos , Animais , Clonagem Molecular , Infecções por Vírus de DNA/genética , Infecções por Vírus de DNA/virologia , DNA Complementar/genética , DNA Complementar/metabolismo , Doenças dos Peixes/genética , Doenças dos Peixes/virologia , Proteínas de Peixes/química , Proteínas de Peixes/metabolismo , Regulação da Expressão Gênica , Peptídeos e Proteínas de Sinalização Intracelular/química , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Alinhamento de Sequência/veterinária
13.
Sci Rep ; 14(1): 14304, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38906989

RESUMO

Purchasing energy-saving products is key for public participation in energy conservation and sustainable development. However, the sale of fraudulent energy-saving products has boomed through online shopping, with little research on these products and consumer demands. This study explored the underlying factors driving consumer purchases of fraudulent energy-saving products and measured their impact on environmental awareness. Sales data for such products from four major online shopping platforms were collected. Results suggested unique demand characteristics from consumers who unknowingly purchase fraudulent energy-saving products, referred to as "hidden energy savers", including a preference for moderately priced products, a desire for straightforward energy-saving explanations, and a tendency to seek multiple additional features, even if they conflict with the core functionality. Perceived installation and usage difficulty significantly influences purchasing behavior. A practical survey of freight companies and individual transporters' demand for freight energy-saving products was conducted as a case study to validate the practical application of this research. This study presents a novel perspective on public energy-saving behavior, aiding in creating true energy-saving products, boosting public energy conservation interest, and reducing the negative impact of fraudulent products on environmental awareness. It also sheds light on hidden consumer needs, guiding the development of authentic energy-saving products.

14.
Heliyon ; 10(11): e32013, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38867994

RESUMO

The aim of this study was to investigate the effects of temporal instability and possible heterogeneity on pedestrian accident severity, 48786 accident data from 2018 to 2021 in the UK STATS database were used as the study object, and accident severity was used as the dependent variable, and 49 accident characteristics were selected as independent variables from 6 characteristics of accident pedestrian, driver, vehicle, road, environment and time to construct the pedestrian accident mean heterogeneity random-parameter logit model and examined its temporal stability. The results of model estimation and likelihood ratio tests indicate that the variables affecting pedestrian injury severity are highly variable and not stable over the years. And further demonstrates the potential of models that address unobserved heterogeneity for significant relationships in pedestrian accident severity analyses.

15.
Sci Rep ; 14(1): 17664, 2024 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-39085290

RESUMO

The utilization of high-risk test cases constitutes an effective approach to enhance the safety testing of autonomous vehicles (AVs) and enhance their efficiency. This research paper presents a derivation of 2052 high-hazard pre-crash scenarios for testing autonomous driving, which were based on 23 high-hazard cut-in accident scenarios from the National Automobile Accident In-Depth Investigation System (NAIS) through combining importance sampling and combined testing methods. Compared to the direct combination of the original distribution after sampling, the proposed method has a 2.92 times higher crash rate of 69.32% for the test case set in this paper. It also has a 5.8 times higher rate of triggering Automatic Emergency Braking (AEB), improving hazardous scenario coverage. Using the proposed method, the generated parameters of the cut-in accident scenario test set were compared with those of the cut-in test scenarios included in existing Chinese autonomous driving test protocols and standards. The velocity of the ego-vehicle obtained using the proposed method matched those in the existing protocols, whereas the velocity, time gap, and time to collision of the target vehicle were significantly lower than those existing protocols indicating scenarios obtained from accident data can enrich the selection of testing scenarios for autonomous driving.

16.
Sci Rep ; 13(1): 22621, 2023 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-38114656

RESUMO

The safety of vehicle occupants in oblique collision scenarios continues to pose challenges, even with the implementation of Automatic Emergency Braking (AEB) systems. While AEB reduces collision risks, studies indicate it may heighten injury risks for out-of-position (OOP) occupants. To counteract this issue, the integration of active seat belts in vehicles equipped with AEB systems is recommended. Firstly, this study established an oblique angle collision scenario post-AEB activation using data from the Chinese National Automobile Accident In-depth Investigation System (NAIS) database, analyzed through Prescan software. The dynamic response of the vehicle was examined. Following this, finite element (FE) models were validated to assess the effects of collision overlap rate, AEB braking strategy, and active seat belt pre-tensioning on occupant injuries and kinematics. Under specific collision conditions, the impact of the timing and amount of seat belt pre-tensioning, as well as airbag deployment timing on occupant injuries, was also explored. Findings revealed that a 75% collision overlap rate significantly increases driver injury risk. Active seat belts effectively mitigate injuries caused by OOP statuses during AEB interventions, with the lowest Weighted Injury Criterion (WIC) observed at a pre-tensioning time of 200 ms for active seat belts. The study further suggests that optimal results in reducing occupant injuries are achieved when active pre-tensioning seat belts are complemented by appropriately timed airbag deployment.


Assuntos
Cintos de Segurança , Ferimentos e Lesões , Humanos , Acidentes de Trânsito/prevenção & controle , Automóveis , Fenômenos Biomecânicos , Bases de Dados Factuais , Ferimentos e Lesões/epidemiologia , Ferimentos e Lesões/etiologia , Ferimentos e Lesões/prevenção & controle
17.
PLoS One ; 18(3): e0282779, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36888638

RESUMO

The aim of this study was to investigate the influence of road factors on the safety speed threshold of a lorry turning right around a corner at a the bottom of a long downhill T-junction. Trucksim simulation software was chosen to construct a model for investigating the turning instability mechanism. A three-axle truck was chosen as the simulation vehicle and road adhesion coefficients of 0.2-0.75, road super-elevations of -2-8%, turning radii of 20-100 m, and vehicle overcharge of 0-100% selected for tuning. Simulation experiments were carried out for different bending conditions, investigating the effects of each influencing factor on the destabilization speed threshold using the control variable method. The vehicle's lateral load transfer rate and lateral acceleration were indicators for determining whether a truck was unstable. The results showed that: a) the turning radius had the most significant influence on the speed threshold for cornering instability; b) the road surface adhesion coefficient and vehicle overweight had secondary effects; and c) the road height had a general influence.

18.
Accid Anal Prev ; 173: 106709, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35597224

RESUMO

The statistical analysis was conducted on data of accident scenarios between cars and two-wheelers from National Automobile Accident In-depth Investigation System (NAIS) database in order to study safety of intended functionality of Autonomous emergency braking (AEB) perception system in typical dangerous scenarios of cars and two-wheelers. 11 scenario-related variables were selected, and 6 types of typical scenarios were obtained through cluster analysis and manual classification. The 6 types of typical scenarios were built by the automatic driving simulation software PreScan, and the AEB longitudinal control algorithm was built in Matlab/Simulink. Batch simulation script files were written, and the relative location distribution of car and two-wheeler with different time to collision (TTC) was obtained by batch simulation. Furthermore, the effects of car velocity, two-wheeler velocity and cyclist casualties on the parameter configuration of the perception system were analyzed. Under the premise of satisfying safety of intended functionality of the perception system, the optimal sensor detection scheme at different TTCs was obtained by comprehensively considering the death accident detection rate, detection area, and standard deviation. The results show that when the detection rate is 90%, the AEB system can adopt the detection scheme of long-range radar and short-range radar. The field of view (FOV) and detection range of the short range radar are 133.6° and 38.1 m, and those of the long range radar are 84.5° and 74.3 m. And when the detection rate was close to 100%, a single sensor can be used, and the detection parameters are 150° and 77.6 m. It provides reference for parameter optimization of AEB perception system.


Assuntos
Condução de Veículo , Automóveis , Acidentes de Trânsito/prevenção & controle , Desaceleração , Humanos , Percepção , Equipamentos de Proteção
19.
J Pharm Sci ; 111(5): 1391-1400, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34563534

RESUMO

We developed a composite system combining self-targeted carbon dots and thermosensitive in situ hydrogels for ocular drug delivery of diclofenac sodium (DS). DS-CDC-HP nanoparticles were prepared by loading DS on the surface of CDC-HP via electrostatic interactions. An orthogonal experimental design was selected to screen the optimal thermosensitive hydrogel matrices and then DS-CDC-HP nanoparticles were embedded to form the composite system. The physicochemical properties and release behavior of this system were characterized, and in vivo fluorescence imaging was carried out. Corneal penetrability and in vitro cellular studies (cytotoxicity, cell imaging and cell uptake) were performed to test the feasibility and potential of this ocular delivery system. Finally, the optimal gel matrix consisting of Poloxamer 407: Poloxamer 188: HPMC E50 was 21:1:1 (w/v %), and the gelation temperature before adding artificial tear fluid was 26.67°C and 34.29°C, respectively. This system has the characteristics of biphasic drug release. In addition, the corneal penetrability and in vivo fluorescence study indicated that corneal transmittance was enhanced and drug retention time was extended. Cellular studies revealed that the DS-CDC-HP-Gel has good cytocompatibility and CD44 targeting. In summary, this composite system combines carbon dots with hydrogels, offering new potential for ocular drug delivery.


Assuntos
Carbono , Hidrogéis , Diclofenaco , Sistemas de Liberação de Medicamentos/métodos , Olho , Hidrogéis/química , Poloxâmero/química , Temperatura
20.
Accid Anal Prev ; 150: 105857, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33285448

RESUMO

Road safety remains a challenge with numerous Vulnerable Road Users (VRUs) suffering from injuries and death every year. Pedestrian protection using active safety systems, such as Automated Emergency Braking (AEB), is an effective measure to combat the situation. Furthermore, the perception of precrash scenarios plays an important role in active safety research. It is essential to understand and define precrash scenarios. This study aimed to apply the obtained typical car-to-pedestrian precrash scenarios from Chinese severely injured pedestrian traffic accidents to develop and test active safety systems. The National Automobile Accident In-Depth Investigation System (NAIS) recorded 467 cases from 2011 to 2018 in China, and 12 items were selected from the NAIS database as description variables for the precrash scenario. The items were divided into four categories: car, pedestrian, road, and environment. Group decision theory was applied to evaluate the importance of each variable in its category. A total of 34 basic scenarios were defined and obtained according to the extracted significant variables. These basic scenarios represented diverse fatal scenarios in China which are crucial for autonomous driving. The frequency distribution of the scenarios demonstrated that the top five scenarios covered 85.3 % of the total. Five scenarios were identified to have the common characteristic of cars going straight. Additionally, 13 detailed scenarios were obtained from the five basic scenarios by using cluster and frequency analyses. In contrast to the New Car Assessment Program (NCAP) test scenarios, weather and lighting conditions were considered in these 13 scenarios, and the driving speed before the crash were mostly distributed in the range of 40-80 km/h (20-60 km/h in the NCAP). Meanwhile, both walking and running were commonly recorded for pedestrians to cross the street from the nearside, compared with records of walking only to cross from the nearside in the NCAP. These results contribute to a reference for test scenarios of pedestrian AEB or Forward Collision Warning (FCW) in China.


Assuntos
Condução de Veículo , Pedestres , Ferimentos e Lesões , Acidentes de Trânsito/prevenção & controle , Automóveis , China , Humanos , Ferimentos e Lesões/prevenção & controle
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