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1.
Biophys Rep ; 10(4): 241-253, 2024 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-39281200

RESUMO

The whole heart decellularized extracellular matrix (ECM) has become a promising scaffold material for cardiac tissue engineering. Our previous research has shown that the whole heart acellular matrix possesses the memory function regulating neural stem cells (NSCs) trans-differentiating to cardiac lineage cells. However, the cell subpopulations and phenotypes in the trans-differentiation of NSCs have not been clearly identified. Here, we performed single-cell RNA sequencing and identified 2,765 cells in the recellularized heart with NSCs revealing the cellular diversity of cardiac and neural lineage, confirming NSCs were capable of trans-differentiating into the cardiac lineage while maintaining the original ability to differentiate into the neural lineage. Notably, the trans-differentiated heart-like cells have dual signatures of neuroectoderm and cardiac mesoderm. This study unveils an in-depth mechanism underlying the trans-differentiation of NSCs and provides a new opportunity and theoretical basis for cardiac regeneration.

2.
Theranostics ; 14(13): 5316-5335, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39267778

RESUMO

Background: Enhancing white adipose tissue (WAT) browning combats obesity. The RIIß subunit of cAMP-dependent protein kinase (PKA) is primarily expressed in the brain and adipose tissue. Deletion of the hypothalamic RIIß gene centrally induces WAT browning, yet the peripheral mechanisms mediating this process remain unexplored. Methods: This study investigates the mechanisms underlying WAT browning in RIIß-KO mice. Genetic approaches such as ß3-adrenergic receptors (ß3ARs) deletion and sympathetic denervation of WAT were utilized. Genome-wide transcriptomic sequencing and bioinformatic analysis were employed to identify potential mediators of WAT browning. siRNA assays were employed to knock down mTOR and lipin1 in vitro, while AAV-shRNAs were used for the same purpose in vivo. Results: We found that WAT browning substantially contributes to the lean and obesity-resistant phenotypes of RIIß-KO mice. The WAT browning can be dampened by ß3ARs deletion or WAT sympathetic denervation. We identified that adipocytic mTOR and lipin1 may act as mediators of the WAT browning. Inhibition of mTOR or lipin1 abrogates WAT browning and hinders the lean phenotype of RIIß-KO mice. In human subcutaneous white adipocytes and mouse white adipocytes, ß3AR stimulation can activate mTOR and causes lipin1 nuclear translocation; knockdown of mTOR and Lipin1 mitigates WAT browning-associated gene expression, impedes mitochondrial activity. Moreover, mTOR knockdown reduces lipin1 level and nuclear translocation, indicating that lipin1 may act downstream of mTOR. Additionally, in vivo knockdown of mTOR and Lipin1 diminished WAT browning and increased adiposity. Conclusions: The ß3AR-activated mTOR-lipin1 axis mediates WAT browning, offering new insights into the molecular basis of PKA-regulated WAT browning. These findings provide potential adipose target candidates for the development of drugs to treat obesity.


Assuntos
Tecido Adiposo Marrom , Tecido Adiposo Branco , Camundongos Knockout , Fosfatidato Fosfatase , Serina-Treonina Quinases TOR , Animais , Serina-Treonina Quinases TOR/metabolismo , Camundongos , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/metabolismo , Fosfatidato Fosfatase/metabolismo , Fosfatidato Fosfatase/genética , Obesidade/metabolismo , Obesidade/genética , Subunidade RIIbeta da Proteína Quinase Dependente de AMP Cíclico/metabolismo , Subunidade RIIbeta da Proteína Quinase Dependente de AMP Cíclico/genética , Receptores Adrenérgicos beta 3/metabolismo , Receptores Adrenérgicos beta 3/genética , Transdução de Sinais , Masculino , Camundongos Endogâmicos C57BL , Humanos , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo
3.
Acta Biomater ; 185: 173-189, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-39025391

RESUMO

Tumor behavior, including its response to treatments, is influenced by interactions between mesenchymal and malignant cells, as well as their spatial arrangement. To study tumor biology and evaluate anticancer drugs, accurate 3D tumor models are essential. Here, we developed an in vitro biomimetic hepatoma microenvironment model by combining an extracellular matrix (3DM-7721). Initially, the internal grid structure, composed of 10/6 % GelMA/gelatin loaded with SMMC-7721 cells, was printed using 3D bioprinting. The external component consisted of fibroblasts and human umbilical vein endothelial cells loaded with 10/3 % GelMA/gelatin. A control model (3DP-7721) lacked external cell loading. GelMA/gelatin hydrogels provided robust structural support and biocompatibility. The SMMC-7721 cells in the 3DM-7721 model exhibit superior tumor-associated gene expression and proliferation characteristics when compared to the 3DP-7721 model. Furthermore, the 3DM-7721 type exhibited increased resistance to anticancer agents. SMMC-7721 cells in the 3DM-7721 model exhibit significant tumorigenicity in nude mice. The 3DM-7721 model group showed pathological characteristics of malignant tumors, with a high degree of deterioration, and a significant positive correlation between malignant tumor-related gene pathways. This high-fidelity 3DM-7721 tumor microenvironment model is invaluable for studying tumor progression, devising effective treatment strategies, and discovering drugs. STATEMENT OF SIGNIFICANCE.


Assuntos
Antineoplásicos , Bioimpressão , Carcinoma Hepatocelular , Neoplasias Hepáticas , Camundongos Nus , Impressão Tridimensional , Microambiente Tumoral , Humanos , Microambiente Tumoral/efeitos dos fármacos , Animais , Bioimpressão/métodos , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/metabolismo , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/metabolismo , Linhagem Celular Tumoral , Antineoplásicos/farmacologia , Células Endoteliais da Veia Umbilical Humana/metabolismo , Ensaios de Seleção de Medicamentos Antitumorais , Camundongos , Gelatina/química , Camundongos Endogâmicos BALB C , Proliferação de Células/efeitos dos fármacos
4.
PeerJ ; 12: e17582, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39006025

RESUMO

Background: Disruptions in calcium homeostasis are associated with a wide range of diseases, and play a pivotal role in the development of cancer. However, the construction of prognostic models using calcium extrusion-related genes in colon adenocarcinoma (COAD) has not been well studied. We aimed to identify whether calcium extrusion-related genes serve as a potential prognostic biomarker in the COAD progression. Methods: We constructed a prognostic model based on the expression of calcium extrusion-related genes (SLC8A1, SLC8A2, SLC8A3, SLC8B1, SLC24A2, SLC24A3 and SLC24A4) in COAD. Subsequently, we evaluated the associations between the risk score calculated by calcium extrusion-related genes and mutation signature, immune cell infiltration, and immune checkpoint molecules. Then we calculated the immune score, stromal score, tumor purity and estimate score using the Estimation of STromal and Immune cells in MAlignant Tumor tissues using Expression data (ESTIMATE) algorithm. The response to immunotherapy was assessed using tumor immune dysfunction and exclusion (TIDE). Finally, colorectal cancer cells migration, growth and colony formation assays were performed in RKO cells with the overexpression or knockdown SLC8A3, SLC24A2, SLC24A3, or SLC24A4. Results: We found that patients with high risk score of calcium extrusion-related genes tend to have a poorer prognosis than those in the low-risk group. Additionally, patients in high-risk group had higher rates of KRAS mutations and lower MUC16 mutations, implying a strong correlation between KRAS and MUC16 mutations and calcium homeostasis in COAD. Moreover, the high-risk group showed a higher infiltration of regulatory T cells (Tregs) in the tumor microenvironment. Finally, our study identified two previously unreported model genes (SLC8A3 and SLC24A4) that contribute to the growth and migration of colorectal cancer RKO cells. Conclusions: Altogether, we developed a prognostic risk model for predicting the prognosis of COAD patients based on the expression profiles of calcium extrusion-related genes, Furthermore, we validated two previously unreported tumor suppressor genes (SLC8A3 and SLC24A4) involved in colorectal cancer progression.


Assuntos
Adenocarcinoma , Neoplasias do Colo , Humanos , Prognóstico , Neoplasias do Colo/genética , Neoplasias do Colo/patologia , Neoplasias do Colo/mortalidade , Adenocarcinoma/genética , Adenocarcinoma/patologia , Adenocarcinoma/imunologia , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Cálcio/metabolismo , Regulação Neoplásica da Expressão Gênica , Linhagem Celular Tumoral , Masculino , Feminino , Mutação
5.
Oncol Lett ; 28(1): 305, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38774454

RESUMO

Esculetin (Esc), a coumarin derivative and herbal medicinal compound used in traditional Chinese medicine, is extracted from Fraxinus chinensis. Esc has shown notable potential in the inhibition of proliferation, metastasis and cell cycle arrest in various cancer cell lines. The present review is based on research articles regarding Esc in the field of carcinoma, published between 2009 and 2023. These studies have unanimously demonstrated that Esc can effectively inhibit cancer cell proliferation through diverse mechanisms and modulate multiple signaling pathways, such as Wnt/ß-catenin, PI3K/Akt, MAPK and janus kinase/signal transducer and activator of transcription-3. In addition, the safety profile of Esc has been demonstrated in credible animal experiments, which has indicated Esc as an effective compound. Furthermore, the combination therapy of Esc with commonly used chemotherapeutic drugs holds great promise. The aim of the present review was to encourage further studies and applications of Esc in cancer therapy.

6.
J Cosmet Dermatol ; 23(9): 2989-2995, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38666442

RESUMO

BACKGROUND: Double-eyelid blepharoplasty is a popular cosmetic procedure in Asia; however, there are some drawbacks to this procedure for mild blepharoptosis. Enhancing movement of the levator aponeurosis can correct blepharoptosis through the release of fibrous web bands present between the preaponeurotic fat pad and levator aponeurosis. AIM: To improve our understanding of the anatomical link between the levator aponeurosis and orbital septum fat and to introduce that the release of the link can provide favorable results in double-eyelid blepharoplasty. PATIENTS/METHODS: We included patients with latent ptosis or subclinical blepharoptosis who underwent double-eyelid blepharoplasty with the release of fibrous web bands between June 2021 and March 2023. Mild ptosis was corrected following complete release of the fibrous bands beneath the preaponeurotic fat pad. Patients were followed up for 4-12 months postoperatively, and surgical outcomes were evaluated. Patient demographic variables and photographs were collected pre- and postoperatively. Patients, surgeons, and laypersons were asked to evaluate the outcomes postoperatively. The Friedman's nonparametric (for repeated measures) two-way analysis of variance was used for statistical analyses. RESULTS: Outcomes were assessed in 45 individuals with an average monitoring period of 6.9 months. There were no cases of incomplete eyelid closure or upper eyelid ectropion. Over 50% of the surgical outcomes were deemed "satisfactory" by each of the three groups in relation to the widening of the eyelid fissure. Most of the examined patients demonstrated favorable long-term results. CONCLUSIONS: Fibrous web bands are implicated in subclinical or mild blepharoptosis. The release of fibrous web bands between the preaponeurotic fat pad and levator aponeurosis can provide favorable results in double-eyelid blepharoplasty.


Assuntos
Tecido Adiposo , Aponeurose , Blefaroplastia , Blefaroptose , Pálpebras , Músculos Oculomotores , Humanos , Blefaroplastia/métodos , Blefaroptose/cirurgia , Feminino , Tecido Adiposo/cirurgia , Aponeurose/cirurgia , Adulto , Masculino , Pálpebras/cirurgia , Pessoa de Meia-Idade , Músculos Oculomotores/cirurgia , Resultado do Tratamento , Adulto Jovem , Satisfação do Paciente , Seguimentos
7.
Phys Chem Chem Phys ; 26(11): 8704-8715, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38415756

RESUMO

Despite extensive studies on the thermodynamic mechanism governing molecular adsorption at the solid-water interface, a comprehensive understanding of the crucial role of interface properties in mediating the entropy-enthalpy compensation during adsorption is lacking, particularly at a quantitative level. Herein, we employed two types of surface models (hydroxyapatite and graphene) along with a series of amino acids to successfully elucidate how distinct interfacial features dictate the delicate balance between entropy and enthalpy variations. The adsorption of all amino acids on the hydroxyapatite surface is an enthalpy-dominated process, where the water-induced enthalpic component of the free energy and the surface-adsorbate electrostatic interaction term alternatively act as the driving force for adsorption in different regions of the surface. Although favorable interactions are observed between amino acids and the graphene surface, the entropy-enthalpy compensation exhibits dependence on the molecular size of the adsorbates. For small amino acids, favorable enthalpy changes predominantly determine their adsorption behavior; however, larger amino acids tend to bind more tightly with the graphene surface, which is thermodynamically dominated by the entropy variations despite the structural characteristics of amino acids. This study reveals specific entropy-enthalpy mechanisms underlying amino acid adsorption at the solid-liquid interface, providing guidance for surface design and synthesis of new biomolecules.

8.
Int J Biol Macromol ; 262(Pt 2): 130100, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38350582

RESUMO

Cucumber mosaic virus (CMV) causes huge economic losses to agriculture every year; thus, understanding the mechanism of plant resistance to CMV is imperative. In this study, an integrated analysis of transmission electron microscopy (TEM) observations and proteomic results was used to identify cytoarchitectural differences in Nicotiana tabacum cv. NC82 (susceptible) and cv. Taiyan 8 (T.T.8; resistant) following infection with CMV. The TEM observations showed that the structure of the chloroplasts and mitochondria was severely damaged at the late stage of infection in NC82. Moreover, the chloroplast stroma and mitochondrial cristae were reduced and disaggregated. However, in T.T.8, organelle structure remained largely intact Selective autophagy predominated in T.T.8, whereas non-selective autophagy dominated in NC82, resembling cellular disorder. Proteomic analysis of T.T.8 revealed differentially expressed proteins (DEPs) mostly associated with photosynthesis, respiration, reactive oxygen species (ROS) scavenging, and cellular autophagy. Biochemical analyses revealed that ROS-related catalase, autophagy-related disulfide isomerase, and jasmonic acid and antioxidant secondary metabolite synthesis-related 4-coumarate:CoA ligase (Nt4CL) exhibited different trends and significant differences in expression in the two cultivars after CMV inoculation. Furthermore, mutant phenotyping verified that reduced Nt4CL expression impaired resistance in T.T.8. The identified DEPs are crucial for maintaining intracellular homeostatic balance and likely contribute to the mechanism of CMV resistance in tobacco. These findings increase our understanding of plant cytological mechanisms conferring resistance to CMV infection.


Assuntos
Cucumovirus , Infecções por Citomegalovirus , Cucumovirus/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Nicotiana , Proteômica/métodos , Doenças das Plantas
10.
J Am Chem Soc ; 146(2): 1681-1689, 2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38178655

RESUMO

The coupled relationship between carrier and phonon scattering severely limits the thermoelectric performance of n-type GeTe materials. Here, we provide an efficient strategy to enlarge grains and induce vacancy clusters for decoupling carrier-phonon scattering through the annealing optimization of n-type GeTe-based materials. Specifically, boundary migration is used to enlarge grains by optimizing the annealing time, while vacancy clusters are induced through the aggregation of Ge vacancies during annealing. Such enlarged grains can weaken carrier scattering, while vacancy clusters can strengthen phonon scattering, leading to decoupled carrier-phonon scattering. As a result, a ratio between carrier mobility and lattice thermal conductivity of ∼492.8 cm3 V-1 s-1 W-1 K and a peak ZT of ∼0.4 at 473 K are achieved in Ge0.67Pb0.13Bi0.2Te. This work reveals the critical roles of enlarged grains and induced vacancy clusters in decoupling carrier-phonon scattering and demonstrates the viability of fabricating high-performance n-type GeTe materials via annealing optimization.

11.
J Craniofac Surg ; 35(1): e83-e85, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37948614

RESUMO

As the relative shortage of healthy tissue obviates the option of local soft tissue coverage, reconstruction of circumferential giant congenital melanocytic nevi (GCMN) on the upper extremity remains particularly challenging. Here the authors report a 3-stage procedure involving pre-expanded pedicled flap from the torso for the reconstruction of upper extremity after circumferential GCMN excision in pediatric patients. The giant nevus was completely removed and the size of the excised nevus was 31 × 14.5 cm. The donor site was primarily closed. No major complication was encountered. Reconstruction with expanded pedicled flap achieved satisfactory results, both functionally and cosmetically.


Assuntos
Nevo Pigmentado , Nevo , Neoplasias Cutâneas , Humanos , Criança , Expansão de Tecido/métodos , Retalhos Cirúrgicos/cirurgia , Nevo Pigmentado/cirurgia , Nevo Pigmentado/congênito , Neoplasias Cutâneas/cirurgia , Neoplasias Cutâneas/congênito , Nevo/cirurgia , Extremidade Superior/cirurgia
12.
Cell ; 187(2): 294-311.e21, 2024 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-38128537

RESUMO

Lactylation is a lactate-induced post-translational modification best known for its roles in epigenetic regulation. Herein, we demonstrate that MRE11, a crucial homologous recombination (HR) protein, is lactylated at K673 by the CBP acetyltransferase in response to DNA damage and dependent on ATM phosphorylation of the latter. MRE11 lactylation promotes its binding to DNA, facilitating DNA end resection and HR. Inhibition of CBP or LDH downregulated MRE11 lactylation, impaired HR, and enhanced chemosensitivity of tumor cells in patient-derived xenograft and organoid models. A cell-penetrating peptide that specifically blocks MRE11 lactylation inhibited HR and sensitized cancer cells to cisplatin and PARPi. These findings unveil lactylation as a key regulator of HR, providing fresh insights into the ways in which cellular metabolism is linked to DSB repair. They also imply that the Warburg effect can confer chemoresistance through enhancing HR and suggest a potential therapeutic strategy of targeting MRE11 lactylation to mitigate the effects.


Assuntos
Proteínas de Ligação a DNA , Proteína Homóloga a MRE11 , Reparo de DNA por Recombinação , Humanos , DNA , Quebras de DNA de Cadeia Dupla , Reparo do DNA , Proteínas de Ligação a DNA/metabolismo , Epigênese Genética , Recombinação Homóloga , Proteína Homóloga a MRE11/metabolismo , Ácido Láctico/metabolismo
13.
J Cell Biol ; 223(1)2024 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-37955924

RESUMO

The EGFR-RAS-ERK pathway is one of the most important signaling cascades in cell survival, growth, and proliferation. Aberrant activation of this pathway is a common mechanism in various cancers. Here, we report that CDK2 is a novel regulator of the ERK pathway via USP37 deubiquitinase (DUB). Mechanistically, CDK2 phosphorylates USP37, which is required for USP37 DUB activity. Further, USP37 deubiquitinates and stabilizes ERK1/2, thereby enhancing cancer cell proliferation. Thus, CDK2 is able to promote cell proliferation by activating USP37 and, in turn, stabilizing ERK1/2. Importantly, combined CDK1/2 and EGFR inhibitors have a synergetic anticancer effect through the downregulation of ERK1/2 stability and activity. Indeed, our patient-derived xenograft (PDX) results suggest that targeting both ERK1/2 stability and activity kills cancer cells more efficiently even at lower doses of these two inhibitors, which may reduce their associated side effects and indicate a potential new combination strategy for cancer therapy.


Assuntos
Sistema de Sinalização das MAP Quinases , Neoplasias , Transdução de Sinais , Humanos , Proliferação de Células , Sobrevivência Celular , Quinase 2 Dependente de Ciclina/antagonistas & inibidores , Receptores ErbB/antagonistas & inibidores , Animais , Neoplasias/tratamento farmacológico
14.
Mol Reprod Dev ; 2023 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-38054257

RESUMO

Polycystic ovary syndrome (PCOS) is an endocrine disorder, affecting women of child-bearing age, and the incidence rate is growing and assuming epidemic proportions. The etiology of PCOS remains unknown and there is no cure. Some animal models for PCOS have been established which have enhanced our understanding of the underlying mechanisms, but omics data for revealing PCOS pathogenesis and for drug discovery are still lacking. In the present study, proteomics analysis was used to construct a protein profile of the ovaries in a PCOS mouse model. The result showed a clear difference in protein profile between the PCOS and control group, with 495 upregulated proteins and 404 downregulated proteins in the PCOS group. The GO term and KEGG pathway analyses of differentially expressed proteins mainly showed involvement in lipid metabolism, oxidative stress, and immune response, which are consistent with pathological characteristics of PCOS in terms of abnormal metabolism, endocrine disorders, chronic inflammation and imbalance between oxidant and antioxidant levels. Also, we found that inflammatory responses were activated in the PCOS ovarium, while lipid biosynthetic process peroxisome, and bile secretion were inhibited. In addition, we found some alteration in unexpected pathways, such as glyoxylate and dicarboxylate metabolism, which should be investigated. The present study makes an important contribution to the current lack of PCOS ovarian proteomic data and provides an important reference for research and development of effective drugs and treatments for PCOS.

15.
Materials (Basel) ; 16(15)2023 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-37569959

RESUMO

The influences of Mg2+ and Ca2+ on the short-term (1800 s) corrosion behavior of X100 pipeline steel were investigated in a sodium chloride (NaCl) solution saturated with CO2. Either Ca2+ or Mg2+ in the solution inhibited the short-term corrosion of X100 pipeline steel, with the corrosion current density decreasing from 262.4 µA cm-2 to 163.5 µA cm-2 or 80.8 µA cm-2. During longer-term (8-48 h) immersion, the Mg2+ inhibited the formation of the protective scale, whereas the Ca2+ accelerated the formation of the scale. Further, an experimental equation establishing the relationship between the precipitation rate of the corrosion scale and the exposure time was proposed to quantitatively study the effects of Mg2+ and Ca2+ on the precipitation rate of the corrosion scale.

16.
Heliyon ; 9(8): e17431, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37554821

RESUMO

Polymer-matrixed materials are widely used in the spacecrafts' structures. However, crafts located in the LEO(Low Earth Orbit) would suffer from hazardous environment factors when orbiting in the space. It has been reported that the space environment factors' integral effect (which represents the factual detriment in space) is not equivalent to the simple summation of each individual. Hence, atomic oxygen and thermal cycling were selected as the starting point for studying the typical LEO synergistic effects on polymer-matrixed space material. In this work, methods such as surface morphology observation, surface components analyzation and inter-laminar-shear strength test were embraced to gather the basic information for the study of degradation. As a result, focusing on the composites selected in this work, synergistic effects do exist between the two factors (AO&TC, representing for atomic oxygen and thermal cycling combined). Besides, a quantified index was proposed to represent synergistic characteristics,so as to lay the foundation for the scientific evolution of material characterization.

17.
Chem Commun (Camb) ; 59(54): 8416-8419, 2023 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-37334622

RESUMO

An efficient copper-catalyzed solvent-switchable regioselective 1,2- or 1,6-addition of quinones with boronic acids has been developed. This novel catalytic protocol for the synthesis of various quinols and 4-phenoxyphenols was enabled by a simple solvent swap between H2O and MeOH. It features mild reaction conditions, simple and easy operation, broad substrate scope and excellent regioselectivity. The gram-scale reactions as well as the further transformations of both addition products were also successfully investigated.

18.
Polymers (Basel) ; 15(10)2023 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-37242840

RESUMO

Obtaining a robust fiber/matrix interface is crucial for enhancing the mechanical performance of fiber-reinforced composites. This study addresses the issue by presenting a novel physical-chemical modification method to improve the interfacial property of an ultra-high molecular weight polyethylene (UHMWPE) fiber and epoxy resin. The UHMWPE fiber was successfully grafted with polypyrrole (PPy) for the first time after a plasma treatment in an atmosphere of mixed oxygen and nitrogen. The results demonstrated that the maximum value of the interfacial shear strength (IFSS) of the UHMWPE fiber/epoxy reached 15.75 MPa, which was significantly enhanced by 357% compared to the pristine UHMWPE fiber. Meanwhile, the tensile strength of the UHMWPE fiber was only slightly reduced by 7.3%, which was furtherly verified by the Weibull distribution analysis. The surface morphology and structure of the PPy in-situ grown UHMWPE fibers were studied using SEM, FTIR, and contact angle measurement. The results showed that the enhancement of the interfacial performance was attributed to the increased fiber surface roughness and in-situ grown groups, which improved the surface wettability between the UHMWPE fibers and epoxy resins.

19.
Small ; 19(33): e2301310, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37080949

RESUMO

Methods allow the enhancement of nanofibers via self-assembly are potentially important for new disciplines with many advantages, including multi-anchor interaction, intrinsic mechanical properties and versatility. Herein, a microfluidic-assisted self-assembly process to construct hydroxyl functionalized boron nitride nanosheets (OH-BNNS)/graphene oxide (GO)/thermoplastic polyurethane (TPU) composite nanofiber film, in which stable and precisely controlled self-assembly is fulfilled by the confined ultra-small-volume chip is demonstrated. Multiple fine structural analyses alongside with the density-functional theory (DFT) calculations are implemented to confirm the synergistic effect of noncovalent interactions (hydrogen bonding interaction, π - π stacking interaction, and van der Waals attraction) plays a critical role in the robust micro-structure and a massive 700% enhancement of mechanical strength via adding only 0.3 wt% OH-BNNS and GO. Importantly, profiled from broadband optical absorption ability, robust mechanical properties and outstanding flexibility, the self-assembled 3D OH-BNNS/GO/TPU nanofiber film reveals an adorable evaporation rate of 4.04 kg m-2  h-1 under one sun illumination with stable energy transfer efficiency (93.2%) by accompanying hydrogen bonding interaction. This microfluidic-assisted self-assembly strategy will provide a constructive entry point for the rational design of nanofibers and beyond.

20.
Adv Sci (Weinh) ; 10(5): e2205173, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36529950

RESUMO

The RIIß subunit of  cAMP-dependent protein kinase A (PKA) is expressed in the brain and adipose tissue. RIIß-knockout mice show leanness and increased UCP1 in brown adipose tissue. The authors have previously reported that RIIß reexpression in hypothalamic GABAergic neurons rescues the leanness. However, whether white adipose tissue (WAT) browning contributes to the leanness and whether RIIß-PKA in these neurons governs WAT browning are unknown. Here, this work reports that RIIß-KO mice exhibit a robust WAT browning. RIIß reexpression in dorsal median hypothalamic GABAergic neurons (DMH GABAergic neurons) abrogates WAT browning. Single-cell sequencing, transcriptome sequencing, and electrophysiological studies show increased GABAergic activity in DMH GABAergic neurons of RIIß-KO mice. Activation of DMH GABAergic neurons or inhibition of PKA in these neurons elicits WAT browning and thus lowers body weight. These findings reveal that RIIß-PKA in DMH GABAergic neurons regulates WAT browning. Targeting RIIß-PKA in DMH GABAergic neurons may offer a clinically useful way to promote WAT browning for treating obesity and other metabolic disorders.


Assuntos
Tecido Adiposo Marrom , Subunidade RIIbeta da Proteína Quinase Dependente de AMP Cíclico , Hipotálamo , Animais , Camundongos , Tecido Adiposo Marrom/metabolismo , Subunidade RIIbeta da Proteína Quinase Dependente de AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Neurônios GABAérgicos/metabolismo , Hipotálamo/metabolismo , Obesidade/metabolismo , Magreza/metabolismo
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