Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 129
Filter
1.
Future Med Chem ; 16(12): 1239-1254, 2024.
Article in English | MEDLINE | ID: mdl-38989990

ABSTRACT

Aim: Chemoresistance in cancer challenges the classical therapeutic strategy of 'one molecule-one target'. To combat this, multi-target therapies that inhibit various cancer-relevant targets simultaneously are proposed. Methods & results: We introduce 5-hydroxybenzothiophene derivatives as effective multi-target kinase inhibitors, showing notable growth inhibitory activity across different cancer cell lines. Specifically, compound 16b, featuring a 5-hydroxybenzothiophene hydrazide scaffold, emerged as a potent inhibitor, displaying low IC50 values against key kinases and demonstrating significant anti-cancer effects, particularly against U87MG glioblastoma cells. It induced G2/M cell cycle arrest, apoptosis and inhibited cell migration by modulating apoptotic markers. Conclusion: 16b represents a promising lead for developing new anti-cancer agents targeting multiple kinases with affinity to the hydroxybenzothiophene core.


[Box: see text].


Subject(s)
Antineoplastic Agents , Apoptosis , Cell Proliferation , Drug Screening Assays, Antitumor , Protein Kinase Inhibitors , Thiophenes , Humans , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemistry , Antineoplastic Agents/chemical synthesis , Thiophenes/pharmacology , Thiophenes/chemistry , Thiophenes/chemical synthesis , Protein Kinase Inhibitors/pharmacology , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/chemical synthesis , Apoptosis/drug effects , Cell Proliferation/drug effects , Structure-Activity Relationship , Cell Line, Tumor , Cell Movement/drug effects , Molecular Structure
2.
J Adv Res ; 2024 Mar 27.
Article in English | MEDLINE | ID: mdl-38548264

ABSTRACT

INTRODUCTION: Overwhelming neutrophil activation and oxidative stress significantly contribute to acute respiratory distress syndrome (ARDS) pathogenesis. However, the potential of repurposing ribociclib, a cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitor used clinically in cancer treatment, for treating neutrophilic ARDS remains uncertain. This study illustrated the ability and underlying mechanism of ribociclib for treating ARDS and neutrophilic inflammation. METHODS: Primary human neutrophils were used to determine the therapeutic effects of ribociclib on respiratory bursts, chemotactic responses, and inflammatory signaling. In vitro and silico analyses were performed to determine the underlying molecular mechanisms. The potential of ribociclib repurposing was evaluated using an in vivo ARDS model in lipopolysaccharide (LPS)-primed mice. RESULTS: We found that treatment using ribociclib markedly limited overabundant oxidative stress (reactive oxygen species [ROS]) production and chemotactic responses (integrin levels and adhesion) in activated human neutrophils. Ribociclib was also shown to act as a selective inhibitor of phosphodiesterase 4 (PDE4), thereby promoting the cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) pathway, leading to the inhibition of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) phosphorylation, and calcium influx. Notably, prophylactic administration and post-treatment with ribociclib ameliorated neutrophil infiltration, lung inflammation, accumulation of oxidative stress, pulmonary destruction, and mortality in mice with LPS-induced ARDS. CONCLUSION: We demonstrated for the first time that ribociclib serves as a novel PDE4 inhibitor for treating neutrophilic inflammation and ARDS. The repurposing ribociclib and targeting neutrophilic PDE4 offer a potential off-label alternative for treating lung lesions and other inflammatory conditions.

3.
Antiviral Res ; 223: 105824, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38309307

ABSTRACT

Coxsackievirus B3 (CVB3), one serotype of enteroviruses, can induce fatal myocarditis and hepatitis in neonates, but both treatment and vaccine are unavailable. Few reports tested antivirals to reduce CVB3. Several antivirals were developed against other enterovirus serotypes, but these antivirals failed in clinical trials due to side effects and drug resistance. Repurposing of clinical drugs targeting cellular factors, which enhance viral replication, may be another option. Parasite and cancer studies showed that the cellular protein kinase B (Akt) decreases interferon (IFN), apoptosis, and interleukin (IL)-6-induced STAT3 responses, which suppress CVB3 replication. Furthermore, miltefosine, the Akt inhibitor used in the clinic for parasite infections, enhances IL-6, IFN, and apoptosis responses in treated patients, suggesting that miltefosine could be the potential antiviral for CVB3. This study was therefore designated to test the antiviral effects of miltefosine against CVB3 in vitro and especially, in mice, as few studies test miltefosine in vitro, but not in vivo. In vitro results showed that miltefosine inhibited viral replication with enhanced activation of the cellular transcription factor, STAT3, which is reported to reduce CVB3 both in vitro and in mice. Notably, STAT3 knockdown abolished the anti-CVB3 activity of miltefosine in vitro. Mouse studies demonstrated that miltefosine pretreatment reduced CVB3 lethality of mice with decreased virus loads, organ damage, and apoptosis, but enhanced STAT3 activation. Miltefosine could be prophylaxis for CVB3 by targeting Akt to enhance STAT3 activation in the mechanism, which is independent of IFN responses and hardly reported in pathogen infections.


Subject(s)
Enterovirus Infections , Phosphorylcholine/analogs & derivatives , STAT3 Transcription Factor , Humans , Animals , Mice , Proto-Oncogene Proteins c-akt , Apoptosis , Antigens, Viral , Enterovirus Infections/drug therapy , Interleukin-6 , Antiviral Agents/pharmacology
4.
J Virol ; 98(1): e0155823, 2024 Jan 23.
Article in English | MEDLINE | ID: mdl-38174926

ABSTRACT

Enterovirus A71 (EV-A71) can induce severe neurological complications and even fatal encephalitis in children, and it has caused several large outbreaks in Taiwan since 1998. We previously generated VP1 codon-deoptimized (VP1-CD) reverse genetics (rg) EV-A71 viruses (rgEV-A71s) that harbor a high-fidelity (HF) 3D polymerase. These VP1-CD-HF rgEV-A71s showed lower replication kinetics in vitro and decreased virulence in an Institute of Cancer Research (ICR) mouse model of EV-A71 infection, while still retaining their antigenicity in comparison to the wild-type virus. In this study, we aimed to further investigate the humoral and cellular immune responses elicited by VP1-CD-HF rgEV-A71s to assess the potential efficacy of these EV-A71 vaccine candidates. Following intraperitoneal (i.p.) injection of VP1-CD-HF rgEV-A71s in mice, we observed a robust induction of EV-A71-specific neutralizing IgG antibodies in the antisera after 21 days. Splenocytes isolated from VP1-CD-HF rgEV-A71s-immunized mice exhibited enhanced proliferative activities and cytokine production (IL-2, IFN-γ, IL-4, IL-6, and TNF-α) upon re-stimulation with VP1-CD-HF rgEV-A71, as compared to control mice treated with adjuvant only. Importantly, administration of antisera from VP1-CD-HF rgEV-A71s-immunized mice protected against lethal EV-A71 challenge in neonatal mice. These findings highlight that our generated VP1-CD-HF rgEV-A71 viruses are capable of inducing both cellular and humoral immune responses, supporting their potential as next-generation EV-A71 vaccines for combating EV-A71 infection.IMPORTANCEEV-A71 can cause severe neurological diseases and cause death in young children. Here, we report the development of synthetic rgEV-A71s with the combination of codon deoptimization and high-fidelity (HF) substitutions that generate genetically stable reverse genetics (rg) viruses as potential attenuated vaccine candidates. Our work provides insight into the development of low-virulence candidate vaccines through a series of viral genetic editing for maintaining antigenicity and genome stability and suggests a strategy for the development of an innovative next-generation vaccine against EV-A71.


Subject(s)
Capsid Proteins , Enterovirus A, Human , Enterovirus Infections , RNA-Dependent RNA Polymerase , Animals , Mice , Antibodies, Viral/immunology , Codon , Enterovirus A, Human/genetics , Enterovirus Infections/immunology , Vaccines, Attenuated , Capsid Proteins/genetics , Immunity, Humoral , Immunity, Cellular , Antibodies, Neutralizing/immunology , Viral Vaccines , Mice, Inbred ICR , Mice, Inbred BALB C , RNA-Dependent RNA Polymerase/genetics
5.
J Am Chem Soc ; 146(1): 263-273, 2024 Jan 10.
Article in English | MEDLINE | ID: mdl-38109718

ABSTRACT

Dual-atom catalysts (DACs) with paired active sites can provide unique intrinsic properties for heterogeneous catalysis, but the synergy of the active centers remains to be elucidated. Here, we develop a high-performance DAC with Zn1Co1 species anchored on nitrogen-doped carbon (Zn1Co1/NC) as the dominant active site for the propane dehydrogenation (PDH) reaction. It exhibits several times higher turnover frequency (TOF) of C3H8 conversion and enhanced C3H6 selectivity compared to Zn1/NC or Co1/NC with only a single-atom site. Various experimental and theoretical studies suggest that the enhanced PDH performance stems from the promoted activation of the C-H bond of C3H8 triggered by the electronic interaction between Zn1 and Co1 colligated by N species. Moreover, the dynamic sinking of the Zn1 site and rising of the Co1 site, together with the steric effect of the dissociated H species at the bridged N during the PDH reaction, provides a feasible channel for C3H6 desorption through the more exposed Co1 site, thereby boosting the selectivity. This work provides a promising strategy for designing robust hetero DACs to simultaneously increase activity and selectivity in the PDH reaction.

7.
Virus Res ; 336: 199203, 2023 Oct 15.
Article in English | MEDLINE | ID: mdl-37625648

ABSTRACT

Fulminant hepatitis is a life-threatening complication of coxsackievirus B (CVB) 3 infections. The condition may deteriorate to disseminated intravascular coagulopathy with markedly increased liver enzymes, inflammatory cytokines, and chemokines, which significantly induce local and systemic inflammation. Curcumin exhibits anti-inflammatory and antiviral characteristics in inflammatory and infectious diseases. Here we determined effects of curcumin on viral replications, cytokine and chemokine expressions, and liver damage in CVB3-infected Huh-7 cells. The mouse-adapted CVB3 strain was used to investigate the antiviral and anti-inflammatory effects of curcumin on CVB3-induced hepatitis in a mouse model. In vitro studies showed that curcumin reduced viral protein and titer levels and increased cell viability. Curcumin enhanced the heme oxygenase-1 (HO-1) protein level and decreased the levels of cleaved caspase-3 protein and mRNA of gene encoding C-X-C motif chemokine 10 in infected cells. In vivo studies showed that curcumin improved the survival rate and clinical scores in mice and reduced the viral titer in the liver during CVB3 infection. Moreover, the HO-1 levels were increased, and the cleaved caspase-3 levels were diminished in the CVB3-infected liver. Curcumin reduced the levels of interferon (IFN)-γ and monokine induced by IFN-γ in liver and levels of interleukin (IL)-8 in serum, but increased levels of regulated activation, normal T cell expression in liver and levels of IL-10 in serum of CVB3-infected mice. In summary, curcumin presents antiviral and anti-inflammation efficacies in CVB3 infection in vitro and in vivo; these results provide potential evidence on the feasibility of curcumin for clinical treatment.

8.
Psychol Res Behav Manag ; 16: 3035-3044, 2023.
Article in English | MEDLINE | ID: mdl-37576445

ABSTRACT

Purpose: Resilience continues to be an important concept in the nursing profession due to its significant role in personal healthcare, patients' healthcare, and leadership. The present study examined the mediating role of perceived stress in the association between mindfulness and resilience among registered nurses in order to understand their importance among those in the Taiwanese nursing profession. Materials and Methods: Between October and November 2021, a total of 816 registered nurses participated in a cross-sectional survey including psychometric measures assessing perceived stress (Chinese Perceived Stress Scale-10), mindfulness (Chinese Mindful Attention Awareness Scale), and resilience (Chinese Questionnaire of Resilience). Results: Results indicated that perceived stress mediated the association between mindfulness and resilience (standardized coefficient = 0.251, p<0.001), although there was no significant association between mindfulness and resilience (standardized coefficient = 0.042, p=0.16). This suggests that perceived stress may function as both distress and eustress because mindfulness was not directly associated with resilience but indirectly via perceived stress. Conclusion: Nurses and their administrators should focus on different ways of coping with stress so that they become more resilient in facing other stressors. Future studies may be conducted to examine the mediating role of perceived stress in the association between other coping strategies and resilience among registered nurses.

9.
Angew Chem Int Ed Engl ; 62(38): e202307470, 2023 Sep 18.
Article in English | MEDLINE | ID: mdl-37523147

ABSTRACT

Borocarbonitride (BCN) materials are newly developed oxidative dehydrogenation catalysts that can efficiently convert alkanes to alkenes. However, BCN materials tend to form bulky B2 O3 due to over-oxidation at the high reaction temperature, resulting in significant deactivation. Here, we report a series of super stable BCN nanosheets for the oxidative dehydrogenation of propane (ODHP) reaction. The catalytic performance of the BCN nanosheets can be easily regulated by changing the guanine dosage. The control experiment and structural characterization indicate that the introduction of a suitable amount of carbon could prevent the formation of excessive B2 O3 from BCN materials and maintain the 2D skeleton at a high temperature of 520 °C. The best-performing catalyst BCN exhibits 81.9 % selectivity towards olefins with a stable propane conversion of 35.8 %, and the propene productivity reaches 16.2 mmol h-1 g-1 , which is much better than hexagonal BN (h-BN) catalysts. Density functional theory calculation results show that the presence of dispersed rather than aggregated carbon atoms can significantly affect the electronic microenvironment of h-BN, thereby boosting the catalytic activity of BCN.

10.
J Med Virol ; 95(8): e28985, 2023 08.
Article in English | MEDLINE | ID: mdl-37505438

ABSTRACT

Herpes simplex virus type 1 (HSV-1) can establish latency in humans and easily relapse in immunocompromised patients, with significant mortality. Treatment with acyclovir (ACV) can result in the emergence of HSV resistance. A total of 440 frozen HSV-1 isolates collected from 318 patients from January 2014 to July 2019 were obtained from National Cheng Kung University Hospital in southern Taiwan. These 440 isolates were subjected to phenotypic studies for ACV-resistance by initial screening with the plaque reduction assay (PRA) and further validation by the DNA reduction assay (DRA). The ACV-resistant strains were further investigated by Sanger sequencing for the full-length UL23 and UL30 genes, which encode thymidine kinase and DNA polymerase, respectively. Hematological malignancies or hematopoietic stem-cell transplantation patients accounted for 56.9% (124/218) among the immunocompromised patients (218/318) in this study. Repeated sampling for HSV testing was 50% (109/218) in immunocompromised patients. Only 1.38% (3/218) of immunocompromised patients and 0.9% (3/318) of all patients developed ACV-resistant HSV-1 as measured by phenotypic screening assays. It is noteworthy that a novel Y248D mutation in the UL23 gene from an immunocompromised patient was found by both PRA and DRA. In 3D protein predicting analysis, uncharged Y248 was located at an alpha-helix and substituted by negative-charged D248, which may alter the function of viral thymidine kinase. Besides, three unreported mutations related to natural polymorphism were found in virus isolates from two immunocompetent patients, including 683-688 deletion, R227H, and A351D in the UL30 gene. These data show that the prevalence of ACV-resistant HSV-1 among immunocompromised patients in southern Taiwan is low. These results will be helpful for the clinical management and treatment of HSV infections.


Subject(s)
Herpes Simplex , Herpesvirus 1, Human , Humans , Acyclovir/pharmacology , Acyclovir/therapeutic use , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , Prevalence , Thymidine Kinase/genetics , Thymidine Kinase/therapeutic use , Taiwan/epidemiology , Neoplasm Recurrence, Local , Herpes Simplex/drug therapy , Herpes Simplex/epidemiology , Mutation , Drug Resistance, Viral/genetics , Immunocompromised Host
11.
J Immunol ; 211(4): 576-590, 2023 08 15.
Article in English | MEDLINE | ID: mdl-37427982

ABSTRACT

TLR signaling in B cells triggers their activation and differentiation independent of help from T cells. Plasmacytoid dendritic cells (pDCs) cooperate with B cells to boost TLR-stimulated T-independent humoral immunity; however, the molecular mechanisms remain elusive. In this study, we demonstrate that in the mouse system, the adjuvant effects of pDCs also occurred following challenge with pathogens and that follicular (FO) B cells were more sensitive to pDC-induced enhancement than were marginal zone (MZ) B cells. Moreover, pDCs migrated to the FO zones and interacted with FO B cells upon stimulation in vivo. CXCL10, a ligand for CXCR3 expressed on pDCs, was superinduced in the coculture system and facilitated the cooperative activation of B cells. Moreover, pDCs also promoted TLR-stimulated autoantibody production in FO B and MZ B cells. Ingenuity Pathway Analysis and gene set enrichment analysis revealed that type I IFN (IFN-I)-mediated JAK-STAT and Ras-MAPK pathways were highly enriched in R848-stimulated B cells cocultured with pDCs compared with B cells alone. Whereas IFN-I receptor 1 deficiency reduced pDC-enhanced B cell responses, STAT1 deficiency displayed a more pronounced defect. One of the STAT1-dependent but IFN-I-independent mechanisms was TLR-induced STAT1-S727 phosphorylation by p38 MAPK. Serine 727 to alanine mutation attenuated the synergism between pDCs and B cells. In conclusion, we uncover a molecular mechanism for pDC-enhanced B cell response and define a crucial role of the IFN-I/TLR-mediated signaling pathway through a p38 MAPK-STAT1 axis in controlling T-independent humoral immunity and providing a novel therapeutic target for treating autoimmune diseases.


Subject(s)
Interferon Type I , p38 Mitogen-Activated Protein Kinases , Mice , Animals , p38 Mitogen-Activated Protein Kinases/metabolism , Signal Transduction , Interferon Type I/metabolism , Phosphorylation , Dendritic Cells
12.
J Microbiol Immunol Infect ; 56(4): 766-771, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37330377

ABSTRACT

BACKGROUND: Maternal transplacental antibody is an important origins of passive immunity against neonatal enterovirus infection. Echovirus 11 (E11) and coxsackievirus B3 (CVB3) are important types causing neonatal infections. There were few investigations of enterovirus D68 (EVD68) infection in neonates. We aimed to investigate the serostatus of cord blood for these three enteroviruses and evaluate the factors associated with seropositivity. METHODS: We enrolled 222 parturient (gestational age 34-42 weeks) women aged 20-46 years old between January and October 2021. All participants underwent questionnaire investigation and we collected the cord blood to measure the neutralization antibodies against E11, CVB3 and EVD68. RESULTS: The cord blood seropositive rates were 18% (41/222), 60% (134/232) and 95% (211/222) for E11, CVB3 and EVD68, respectively (p < 0.001). Geometric mean titers were 3.3 (95% CI 2.9-3.8) for E11, 15.9 (95% CI 12.5-20.3) for CVB3 and 109.9 (95% CI 92.4-131.6) for EVD68. Younger parturient age (33.8 ± 3.6 versus 35.2 ± 4.4, p = 0.04) was related to E11 seropositivity. Neonatal sex, gestational age and birth body weight were not significantly different between the seropositive group and the seronegative group. CONCLUSION: Cord blood seropositive rate and geometric mean titer of E11 were very low, so a large proportion of newborns are susceptible to E11. The circulation of E11 was low after 2019 in Taiwan. A large cohort of immune naïve newborns existed currently due to lack of protective maternal antibodies. It is imminent to monitor the epidemiology of neonates with enterovirus infections and strengthen the relevant preventive policies.


Subject(s)
Communicable Diseases , Enterovirus D, Human , Enterovirus Infections , Enterovirus , Humans , Infant, Newborn , Female , Young Adult , Adult , Middle Aged , Infant , Fetal Blood , Enterovirus B, Human , Antibodies
13.
Eur Radiol ; 33(9): 6290-6298, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37133520

ABSTRACT

OBJECTIVES: The current guidelines contain substantial inconsistency regarding the use of metformin concomitantly with contrast media. The objective of this study is to appraise the guidelines and summarize the agreements and differences among recommendations. METHODS: Our search focused on English language guidelines published between 2018 and 2021. Guidelines for the management of contrast media in patients with continuous metformin were included. Guidelines were assessed using the Appraisal of Guidelines for Research and Evaluation II instrument. RESULTS: Six guidelines out of 1134 fulfilled the inclusion criteria with an AGREE II score of 79.2% (IQR 72.7 to 85.1%). There was good overall quality of the guidelines, with six considered "strongly recommended." CPGs scored poorly in "Clarity of Presentation" and "Applicability," with scores of 75.9% and 76.4%, respectively. The intraclass correlation coefficients were excellent in each domain. There are some guidelines (33.3%) that recommend discontinuation of metformin in patients with an eGFR of < 30 mL/min/1.73 m2, while some guidelines (16.7%) suggest the threshold of renal function should be eGFR < 40 mL/min/1.73 m2. CONCLUSIONS: Most guidelines recommend withdrawing metformin before using contrast agents in diabetic patients with severely impaired kidney function but disagree on the renal function thresholds. Furthermore, the gaps regarding discontinuing metformin with moderate renal impairment (30 mL/min/1.73 m2 < eGFR < 60 mL/min/1.73 m2) must be considered in future studies. KEY POINTS: • Guidelines involving metformin and contrast agents are reliable and optimal. • Most guidelines advocate discontinuing metformin before using contrast agents in diabetic patients with advanced renal failure, but there are controversial suggestions regarding kidney function thresholds. • The gaps regarding the time of discontinuation of the metformin with moderate renal impairment (30 mL/min/1.73 m2 < eGFR < 60 mL/min/1.73 m2) must be considered in the extensive RCT studies.


Subject(s)
Diabetes Mellitus , Metformin , Renal Insufficiency , Humans , Metformin/therapeutic use , Contrast Media , Consensus
14.
Br J Pharmacol ; 180(16): 2172-2188, 2023 08.
Article in English | MEDLINE | ID: mdl-36967633

ABSTRACT

BACKGROUND AND PURPOSE: Neutrophilic inflammation is a critical pathogenic factor in psoriasis. The therapeutic applicability of palbociclib, a cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitor clinically used to treat cancer, in the treatment of neutrophil-associated psoriasis remains undefined. In this study, we evaluated the therapeutic potential and pharmacological effect of palbociclib on neutrophil-associated psoriasiform dermatitis. EXPERIMENTAL APPROACH: The anti-inflammatory effects of palbociclib were determined in activated human neutrophils. The therapeutic feasibility of palbociclib in psoriasis was demonstrated in a mouse model of imiquimod-induced psoriasiform dermatitis. The in vitro enzymatic assays and in silico analyses were used to identify the underlying pharmacological mechanisms. KEY RESULTS: This study found that palbociclib inhibited neutrophilic inflammation, including superoxide anion generation, reactive oxygen species (ROS) formation, elastase degranulation and chemotactic responses. The mechanistic studies identified that the anti-inflammatory effects of palbociclib involved the targeting of phosphatidylinositol 3-kinase (PI3K) but not CDK4/6 in human neutrophils. Palbociclib preferentially targeted the p110δ catalytic subunit of PI3K and thereby blocked signalling via the PI3K/protein kinase B (Akt) pathway. Furthermore, topical application of palbociclib significantly ameliorated imiquimod-induced psoriasiform dermatitis in mice, including psoriatic symptoms, neutrophil infiltration, Akt activation and cytokine up-regulation. CONCLUSIONS AND IMPLICATIONS: This is the first study to demonstrate that palbociclib can potentially be used to treat neutrophil-associated psoriasiform dermatitis through the targeting of neutrophilic PI3K activity. Our findings prompt further research to explore the potential of palbociclib and PI3K in psoriasis and other inflammatory diseases.


Subject(s)
Dermatitis , Psoriasis , Humans , Animals , Mice , Proto-Oncogene Proteins c-akt/metabolism , Imiquimod/adverse effects , Phosphatidylinositol 3-Kinases , Psoriasis/chemically induced , Psoriasis/drug therapy , Psoriasis/metabolism , Inflammation/drug therapy , Anti-Inflammatory Agents/adverse effects , Disease Models, Animal
15.
Polymers (Basel) ; 15(3)2023 Jan 31.
Article in English | MEDLINE | ID: mdl-36772038

ABSTRACT

Interlaminar failure caused by scratches is a common damage mode in automotive coatings and is considered the potential trigger for irreversible destruction, i.e., plowing. This work strives to numerically investigate the mechanisms responsible for the complex scratch behavior of an automotive coating system, considering the interfacial failure. A finite element model is developed by incorporating a large deformation cohesive zone model for scratch-induced debonding simulation, where the mass scaling technique is utilized to minimize computational burden while ensuring accuracy. The delamination phenomenon of the automotive coating is reproduced, and its effects on scratch damage behavior are analyzed. Accordingly, it is revealed that the interlaminar delamination would produce significant stress redistribution, which leads to brittle and ductile damage of the coating and consequently affects the formation of plowing. Eventually, parametric studies on the effects of interfacial properties are performed. They demonstrate that the shear strength and shear fracture energy dominate scratch-induced delamination.

16.
Entropy (Basel) ; 24(12)2022 Dec 08.
Article in English | MEDLINE | ID: mdl-36554201

ABSTRACT

As a potential candidate for the next generation of high-temperature alloys, refractory high entropy alloys (RHEAs) have excellent mechanical properties and thermal stability, especially for high-temperature applications, where the processing of RHEAs plays a critical role in engineering applications. In this work, the wire electrical discharge machining (WEDM) performance of WNbMoTaZrx (x = 0.5, 1) RHEAs was investigated, as compared with tungsten, cemented carbide and industrial pure Zr. The cutting efficiency (CE) of the five materials was significantly dependent on the melting points, while the surface roughness (Ra) was not. For the RHEAs, the CE was significantly affected by the pulse-on time (ON), pulse-off time (OFF) and peak current (IP), while the surface roughness was mainly dependent on the ON and IP. The statistical analyses have shown that the CE data of RHEAs have relatively-smaller Weibull moduli than those for the Ra data, which suggests that the CE of RHEAs can be tuned by optimizing the processing parameters. However, it is challenging to tune the surface roughness of RHEAs by tailoring the processing parameters. Differing from the comparative materials, the WEDMed surfaces of the RHEAs showed dense spherical re-solidified particles at upper recast layers, resulting in larger Ra values. The proportion of the upper recast layers can be estimated by the specific discharge energy (SDE). Following the WEDM, the RHEAs maintained the main BCC1 phase, enriched with the W and Ta elements, while the second BCC2 phase in the Zr1.0 RHEA disappeared. Strategies for achieving a better WEDMed surface quality of RHEAs were also proposed and discussed.

17.
Front Pharmacol ; 13: 1014823, 2022.
Article in English | MEDLINE | ID: mdl-36339581

ABSTRACT

Neonatal infection with nonpolio enteroviruses (EVs) causes nonspecific febrile illnesses and even life-threatening multiorgan failure. Hepatitis, which often results in hepatic necrosis followed by disseminated intravascular coagulopathy, is one of the most severe and frequent fatal neonatal EV infection complications. Coxsackievirus B (CVB) 1-5 and many echoviruses have been most commonly identified. Neonatal EV infection treatment has usually involved initial supportive care. Studies for CVB and echovirus infection treatments were developed for more than thirty years. Intravenous immunoglobulin and pleconaril therapy was performed in some clinical trials. Additionally, other studies demonstrated antiviral and/or anti-inflammatory pathogenesis mechanisms of neonatal EV hepatitis in in vitro or in vivo models. These treatments represented promising options for the clinical practice of neonatal EV hepatitis. However, further investigation is needed to elucidate the whole therapeutic potential and safety problems.

18.
Entropy (Basel) ; 24(11)2022 Oct 28.
Article in English | MEDLINE | ID: mdl-36359643

ABSTRACT

During the past decade, refractory high-entropy alloys (RHEA) have attracted great attention of scientists, engineers and scholars due to their excellent mechanical and functional properties. The W-containing RHEAs are favored by researchers because of their great application potential in aerospace, marine and nuclear equipment and other high-temperature, corrosive and irradiated fields. In this review, more than 150 W-containing RHEAs are summarized and compared. The preparation techniques, microstructure and mechanical properties of the W-containing RHEAs are systematically outlined. In addition, the functional properties of W-containing RHEAs, such as oxidation, corrosion, irradiation and wear resistance have been elaborated and analyzed. Finally, the key issues faced by the development of W-containing RHEAs in terms of design and fabrication techniques, strengthening and deformation mechanisms, and potential functional applications are proposed and discussed. Future directions for the investigation and application of W-containing RHEAs are also suggested. The present work provides useful guidance for the development, processing and application of W-containing RHEAs and the RHEA components.

19.
PLoS Pathog ; 18(8): e1010692, 2022 08.
Article in English | MEDLINE | ID: mdl-35939498

ABSTRACT

Herpes simplex virus 1 (HSV-1)-induced encephalitis is the most common cause of sporadic, fatal encephalitis in humans. HSV-1 has at least 10 different envelope glycoproteins, which can promote virus infection. The ligands for most of the envelope glycoproteins and the significance of these ligands in virus-induced encephalitis remain elusive. Here, we show that glycoprotein E (gE) binds to the cellular protein, annexin A1 (Anx-A1) to enhance infection. Anx-A1 can be detected on the surface of cells permissive for HSV-1 before infection and on virions. Suppression of Anx-A1 or its receptor, formyl peptide receptor 2 (FPR2), on the cell surface and gE or Anx-A1 on HSV-1 envelopes reduced virus binding to cells. Importantly, Anx-A1 knockout, Anx-A1 knockdown, or treatments with the FPR2 antagonist reduced the mortality and tissue viral loads of infected mice. Our results show that Anx-A1 is a novel enhancing factor of HSV-1 infection. Anx-A1-deficient mice displayed no evident physiology and behavior changes. Hence, targeting Anx-A1 and FPR2 could be a promising prophylaxis or adjuvant therapy to decrease HSV-1 lethality.


Subject(s)
Annexin A1 , Encephalitis , Herpes Simplex , Herpesvirus 1, Human , Animals , Annexin A1/genetics , Annexin A1/metabolism , Glycoproteins/metabolism , Herpesvirus 1, Human/metabolism , Humans , Mice
20.
Pharmaceuticals (Basel) ; 15(7)2022 Jun 22.
Article in English | MEDLINE | ID: mdl-35890077

ABSTRACT

For many inflammatory diseases, new effective drugs with fewer side effects are needed. While it appears promising to target the activation of the central pro-inflammatory transcription factor NF-κB, many previously discovered agents suffered from cytotoxicity. In this study, new alkylthiourea quinazoline derivatives were developed that selectively inhibit the activation of NF-κB in macrophage-like THP-1 cells while showing low general cytotoxicity. One of the best compounds, 19, strongly inhibited the production of IL-6 (IC50 = 0.84 µM) and, less potently, of TNFα (IC50 = 4.0 µM); in comparison, the reference compound, caffeic acid phenethyl ester (CAPE), showed IC50s of 1.1 and 11.4 µM, respectively. Interestingly, 19 was found to block the translocation of the NF-κB dimer to the nucleus, although its release from the IκB complex was unaffected. Furthermore, 19 suppressed the phosphorylation of NF-κB-p65 at Ser468 but not at Ser536; however, 19 did not inhibit any kinase involved in NF-κB activation. The only partial suppression of p65 phosphorylation might be associated with fewer side effects. Since several compounds selectively induced cell death in activated macrophage-like THP-1 cells, they might be particularly effective in various inflammatory diseases that are exacerbated by excess activated macrophages, such as arteriosclerosis and autoimmune diseases.

SELECTION OF CITATIONS
SEARCH DETAIL
...