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1.
Nature ; 590(7845): 262-267, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33568822

RESUMEN

Steels with sub-micrometre grain sizes usually possess high toughness and strength, which makes them promising for lightweighting technologies and energy-saving strategies. So far, the industrial fabrication of ultrafine-grained (UFG) alloys, which generally relies on the manipulation of diffusional phase transformation, has been limited to steels with austenite-to-ferrite transformation1-3. Moreover, the limited work hardening and uniform elongation of these UFG steels1,4,5 hinder their widespread application. Here we report the facile mass production of UFG structures in a typical Fe-22Mn-0.6C twinning-induced plasticity steel by minor Cu alloying and manipulation of the recrystallization process through the intragranular nanoprecipitation (within 30 seconds) of a coherent disordered Cu-rich phase. The rapid and copious nanoprecipitation not only prevents the growth of the freshly recrystallized sub-micrometre grains but also enhances the thermal stability of the obtained UFG structure through the Zener pinning mechanism6. Moreover, owing to their full coherency and disordered nature, the precipitates exhibit weak interactions with dislocations under loading. This approach enables the preparation of a fully recrystallized UFG structure with a grain size of 800 ± 400 nanometres without the introduction of detrimental lattice defects such as brittle particles and segregated boundaries. Compared with the steel to which no Cu was added, the yield strength of the UFG structure was doubled to around 710 megapascals, with a uniform ductility of 45 per cent and a tensile strength of around 2,000 megapascals. This grain-refinement concept should be extendable to other alloy systems, and the manufacturing processes can be readily applied to existing industrial production lines.

2.
Nat Mater ; 23(6): 755-761, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38605195

RESUMEN

The strength-ductility trade-off has long been a Gordian knot in conventional metallic structural materials and it is no exception in multi-principal element alloys. In particular, at ultrahigh yield strengths, plastic instability, that is, necking, happens prematurely, because of which ductility almost entirely disappears. This is due to the growing difficulty in the production and accumulation of dislocations from the very beginning of tensile deformation that renders the conventional dislocation hardening insufficient. Here we propose that premature necking can be harnessed for work hardening in a VCoNi multi-principal element alloy. Lüders banding as an initial tensile response induces the ongoing localized necking at the band front to produce both triaxial stress and strain gradient, which enables the rapid multiplication of dislocations. This leads to forest dislocation hardening, plus extra work hardening due to the interaction of dislocations with the local-chemical-order regions. The dual work hardening combines to restrain and stabilize the premature necking in reverse as well as to facilitate uniform deformation. Consequently, a superior strength-and-ductility synergy is achieved with a ductility of ~20% and yield strength of 2 GPa during room-temperature and cryogenic deformation. These findings offer an instability-control paradigm for synergistic work hardening to conquer the strength-ductility paradox at ultrahigh yield strengths.

3.
BMC Genomics ; 25(1): 673, 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38969975

RESUMEN

BACKGROUND: Culex tritaeniorhynchus is widely distributed in China, from Hainan Island in the south to Heilongjiang in the north, covering tropical, subtropical, and temperate climate zones. Culex tritaeniorhynchus carries 19 types of arboviruses. It is the main vector of the Japanese encephalitis virus (JEV), posing a serious threat to human health. Understanding the effects of environmental factors on Culex tritaeniorhynchus can provide important insights into its population structure or isolation patterns, which is currently unclear. RESULTS: In total, 138 COI haplotypes were detected in the 552 amplified sequences, and the haplotype diversity (Hd) value increased from temperate (0.534) to tropical (0.979) regions. The haplotype phylogeny analysis revealed that the haplotypes were divided into two high-support evolutionary branches. Temperate populations were predominantly distributed in evolutionary branch II, showing some genetic isolation from tropical/subtropical populations and less gene flow between groups. The neutral test results of HNQH (Qionghai) and HNHK(Haikou) populations were negative (P < 0.05), indicating many low-frequency mutations in the populations and that the populations might be in the process of expansion. Moreover, Wolbachia infection was detected only in SDJN (Jining) (2.24%), and all Wolbachia genotypes belonged to supergroup B. To understand the influence of environmental factors on mosquito-borne viruses, we examined the prevalence of Culex tritaeniorhynchus infection in three ecological environments in Shandong Province. We discovered that the incidence of JEV infection was notably greater in Culex tritaeniorhynchus from lotus ponds compared to those from irrigation canal regions. In this study, the overall JEV infection rate was 15.27 per 1000, suggesting the current risk of Japanese encephalitis outbreaks in Shandong Province. CONCLUSIONS: Tropical and subtropical populations of Culex tritaeniorhynchus showed higher genetic diversity and those climatic conditions provide great advantages for the establishment and expansion of Culex tritaeniorhynchus. There are differences in JEV infection rates in wild populations of Culex tritaeniorhynchus under different ecological conditions. Our results suggest a complex interplay of genetic differentiation, population structure, and environmental factors in shaping the dynamics of Culex tritaeniorhynchus. The low prevalence of Wolbachia in wild populations may reflect the recent presence of Wolbachia invasion in Culex tritaeniorhynchus.


Asunto(s)
Culex , Haplotipos , Filogenia , Culex/genética , Culex/virología , Culex/microbiología , Animales , China , Clima , Variación Genética , Genética de Población , Wolbachia/genética , Mosquitos Vectores/genética , Mosquitos Vectores/virología , Mosquitos Vectores/microbiología , Complejo IV de Transporte de Electrones/genética
4.
J Gastroenterol Hepatol ; 39(8): 1509-1516, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38721685

RESUMEN

Hepatitis B virus (HBV) is a hepatotropic non-cytopathic virus characterized by liver-specific gene expression. HBV infection highjacks bile acid metabolism, notably impairing bile acid uptake via sodium taurocholate cotransporting polypeptide (NTCP), which is a functional receptor for HBV entry. Concurrently, HBV infection induces changes in bile acid synthesis and the size of the bile acid pool. Conversely, bile acid facilitates HBV replication and expression through the signaling molecule farnesoid X receptor (FXR), a nuclear receptor activated by bile acid. However, in HepaRG cells and primary hepatocytes, FXR agonists suppress HBV RNA expression and the synthesis and secretion of DNA. In the gut, the size and composition of the bile acid pool significantly influence the gut microbiota. In turn, the gut microbiota impacts bile acid metabolism and innate immunity, potentially promoting HBV clearance. Thus, the bile acid-gut microbiota axis represents a complex and evolving relationship in the context of HBV infection. This review explores the interplay between bile acid and gut microbiota in HBV infection and discusses the development of HBV entry inhibitors targeting NTCP.


Asunto(s)
Ácidos y Sales Biliares , Microbioma Gastrointestinal , Virus de la Hepatitis B , Hepatitis B , Transportadores de Anión Orgánico Sodio-Dependiente , Receptores Citoplasmáticos y Nucleares , Simportadores , Humanos , Ácidos y Sales Biliares/metabolismo , Transportadores de Anión Orgánico Sodio-Dependiente/metabolismo , Simportadores/metabolismo , Virus de la Hepatitis B/fisiología , Microbioma Gastrointestinal/fisiología , Receptores Citoplasmáticos y Nucleares/metabolismo , Replicación Viral , Internalización del Virus , Inmunidad Innata , Animales
5.
Acta Pharmacol Sin ; 45(8): 1701-1714, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38609562

RESUMEN

Signal transducer and activator of transcription 3 (STAT3) plays an important role in the occurrence and progression of tumors, leading to resistance and poor prognosis. Activation of STAT3 signaling is frequently detected in hepatocellular carcinoma (HCC), but potent and less toxic STAT3 inhibitors have not been discovered. Here, based on antisense technology, we designed a series of stabilized modified antisense oligonucleotides targeting STAT3 mRNA (STAT3 ASOs). Treatment with STAT3 ASOs decreased the STAT3 mRNA and protein levels in HCC cells. STAT3 ASOs significantly inhibited the proliferation, survival, migration, and invasion of cancer cells by specifically perturbing STAT3 signaling. Treatment with STAT3 ASOs decreased the tumor burden in an HCC xenograft model. Moreover, aberrant STAT3 signaling activation is one of multiple signaling pathways involved in sorafenib resistance in HCC. STAT3 ASOs effectively sensitized resistant HCC cell lines to sorafenib in vitro and improved the inhibitory potency of sorafenib in a resistant HCC xenograft model. The developed STAT3 ASOs enrich the tools capable of targeting STAT3 and modulating STAT3 activity, serve as a promising strategy for treating HCC and other STAT3-addicted tumors, and alleviate the acquired resistance to sorafenib in HCC patients. A series of novel STAT3 antisense oligonucleotide were designed and showed potent anti-cancer efficacy in hepatocellular carcinoma in vitro and in vivo by targeting STAT3 signaling. Moreover, the selected STAT3 ASOs enhance sorafenib sensitivity in resistant cell model and xenograft model.


Asunto(s)
Antineoplásicos , Carcinoma Hepatocelular , Proliferación Celular , Resistencia a Antineoplásicos , Neoplasias Hepáticas , Factor de Transcripción STAT3 , Sorafenib , Factor de Transcripción STAT3/metabolismo , Factor de Transcripción STAT3/antagonistas & inhibidores , Carcinoma Hepatocelular/tratamiento farmacológico , Carcinoma Hepatocelular/patología , Carcinoma Hepatocelular/metabolismo , Sorafenib/farmacología , Sorafenib/uso terapéutico , Humanos , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Hepáticas/patología , Neoplasias Hepáticas/metabolismo , Animales , Resistencia a Antineoplásicos/efectos de los fármacos , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Proliferación Celular/efectos de los fármacos , Línea Celular Tumoral , Ratones Desnudos , Oligonucleótidos Antisentido/farmacología , Oligonucleótidos Antisentido/uso terapéutico , Ratones , Ratones Endogámicos BALB C , Ensayos Antitumor por Modelo de Xenoinjerto , Movimiento Celular/efectos de los fármacos , Masculino , Transducción de Señal/efectos de los fármacos , Oligonucleótidos/farmacología
6.
BMC Med Imaging ; 24(1): 68, 2024 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-38515044

RESUMEN

BACKGROUND: Contrast-enhanced ultrasound (CEUS) is considered as an efficient tool for focal liver lesion characterization, given it allows real-time scanning and provides dynamic tissue perfusion information. An accurate diagnosis of liver lesions with CEUS requires a precise interpretation of CEUS images. However,it is a highly experience dependent task which requires amount of training and practice. To help improve the constrains, this study aims to develop an end-to-end method based on deep learning to make malignancy diagnosis of liver lesions using CEUS. METHODS: A total of 420 focal liver lesions with 136 benign cases and 284 malignant cases were included. A deep learning model based on a two-dimensional convolution neural network, a long short-term memory (LSTM), and a linear classifier (with sigmoid) was developed to analyze the CEUS loops from different contrast imaging phases. For comparison, a 3D-CNN based method and a machine-learning (ML)-based time-intensity curve (TIC) method were also implemented for performance evaluation. RESULTS: Results of the 4-fold validation demonstrate that the mean AUC is 0.91, 0.88, and 0.78 for the proposed method, the 3D-CNN based method, and the ML-based TIC method, respectively. CONCLUSIONS: The proposed CNN-LSTM method is promising in making malignancy diagnosis of liver lesions in CEUS without any additional manual features selection.


Asunto(s)
Aprendizaje Profundo , Neoplasias Hepáticas , Humanos , Neoplasias Hepáticas/diagnóstico por imagen , Neoplasias Hepáticas/patología , Medios de Contraste , Ultrasonografía/métodos
7.
Int J Mol Sci ; 25(16)2024 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-39201624

RESUMEN

A growing body of evidence indicates that the G protein-coupled bile acid receptor, TGR5, plays a critical role in multiple physiological processes ranging from metabolic disorders to cancers. However, the biological functions of TGR5 in cervical cancer (CC) have not been elucidated. Here, using TGR5 knockout mice, we found that a deficiency of TGR5 leads to greater sensitivity to the progression of cervical inflammation. Activation of TGR5 by its specific ligands significantly attenuated the malignant behavior of CC cells. In addition, we found that TGR5 can negatively modulate the expression of lncRNA HCP5 by blocking its transcription activation when mediated by p65. HCP5 was highly expressed in CC tissues, which was positively correlated with the poor prognosis of CC patients. HCP5 knockdown notably restrained CC cell proliferation, colony formation, and migration in vitro, and inhibited tumor growth in vivo. Furthermore, HCP5 can function as the molecular sponge for miR-139-5p to upregulate DNA damage-induced transcript 4 (DDIT4) in CC cells. Murine xenograft studies demonstrated that TGR5 suppressed the tumor formation of CC cells and downregulated HCP5 and DDIT4 while increasing miR-139-5p in the xenografts. Taken together, these findings, for the first time, indicate that TGR5 inhibits CC progression by regulating the HCP5/miR-139-5p/DDIT4 axis, suggesting that it may represent a novel and potent target for CC treatment.


Asunto(s)
Proliferación Celular , Regulación Neoplásica de la Expresión Génica , MicroARNs , ARN Largo no Codificante , Receptores Acoplados a Proteínas G , Neoplasias del Cuello Uterino , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/genética , Animales , Humanos , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , MicroARNs/genética , MicroARNs/metabolismo , Neoplasias del Cuello Uterino/genética , Neoplasias del Cuello Uterino/patología , Neoplasias del Cuello Uterino/metabolismo , Femenino , Ratones , Proliferación Celular/genética , Progresión de la Enfermedad , Ratones Noqueados , Línea Celular Tumoral , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Movimiento Celular/genética
8.
Angew Chem Int Ed Engl ; 63(41): e202408802, 2024 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-39039037

RESUMEN

The direct production of hydrogen peroxide (H2O2) through photocatalytic reaction via H2O and O2 is considered as an ideal approach. However, the efficiency of H2O2 generation is generally limited by insufficient charge and mass transfer. Covalent organic framework (COFs) offer a promising platform as metal-free photocatalyst for H2O2 production due to their potential for rational design at the molecular level. Herein, we integrated the multipolar structures and carboxyl groups into COFs to enhance the efficiency of photocatalytic H2O2 production in pure water without any sacrificial agents. The introduction of octupolar and quadrupolar structures, along with an increase of molecular planarity, created efficient oxygen reduction reaction (ORR) sites. Meanwhile, carboxyl groups could not only boost O2 and H2O2 movement via enhancement of pore hydrophilicity, but also promote proton conduction, enabling the conversion to H2O2 from ⋅O2 -, which is the crucial intermediate product in H2O2 photocatalysis. Overall, we demonstrate that TACOF-1-COOH, consisting of optimal octupolar and quadrupolar structures, along with enrichment sites (carboxyl groups), exhibited a H2O2 yield rate of 3542 µmol h- 1 g-1 and a solar-to-chemical (SCC) efficiency of 0.55 %. This work provides valuable insights for designing metal-free photocatalysts for efficient H2O2 production.

9.
Small ; 19(18): e2207403, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36775952

RESUMEN

It is still very challenging to obtain colorful and long-afterglow room-temperature phosphorescent (RTP) materials from pure organic polymers. Herein, it is found that chitosan (CS), a natural polymer, not only has its own RTP, but also reacts with different phosphorescent molecules to obtain a multicolor, long-afterglow RTP material. CS can emit RTP with a lifetime of 48 ms. In addition, CS is rich in amino groups, and grafting different phosphorescent molecules onto CS by an amidation reaction can modulate it to emit different colors of phosphorescence and obtain a series of colorful CS derivatives. The obtained polymer films also have ultra-long RTP due to the good film-forming ability. In addition, one of the CS derivatives selected with α-cyclodextrin is used to construct RTP materials with lifetimes of up to seconds. The host-guest interactions are used to suppress nonradiative relaxation and build crystalline domains, thus synergistically enhancing the RTP. Interestingly, the RTP properties of the CS derivative films are extremely sensitive to water and heat stimuli, because water broke the hydrogen bonds between adjacent CS molecules and thus altered the rigid environment in the material. Finally, they can be used as a stimuli-responsive ink and for monitoring environmental humidity.

10.
Small ; 19(52): e2303933, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37574266

RESUMEN

Exploiting novel strategies for simultaneously harvesting ubiquitous, renewable, and easily accessible solar energy based on the photothermal effect, and efficiently storing the acquired thermal energy plays a vital role in revolutionizing the current fossil fuel-dominating energy structure. Developing black phosphorene-based phase-change composites with optimized photothermal conversion efficiencyand high latent heat is the most promising way to achieve efficient solar energy harvesting and rapid thermal energy storage. However, exfoliating high-quality black phosphorene nanosheets  remains challenging, Furthermore, an efficient strategy that can construct the aligned black phosphorene frameworks to maximize thermal conductivity enhancement is still lacking. Herein, high-quality black phosphorene nanosheets are prepared by an optimized exfoliating strategy. Meanwhile, by regulating the temperature gradient during freeze-casting, the framework consisting of shipshape aligned black phosphorene at long-range is successfully fabricated, improving the thermal conductivity of the poly(ethylene glycol) matrix up to 1.81 W m-1  K-1 at 20 vol% black phosphorene loading. The framework also endows the composite with excellent phase-change material encapsulation capacity and  high latent heat of 103.91 J g-1 . It is envisioned that the work advances the paradigm of contrasting frameworks with nanosheets toward controllable structure thermal enhancement of the composites.

11.
Am J Pathol ; 192(3): 503-517, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-34896072

RESUMEN

The overactivation of canonical Wnt/ß-catenin pathway is one of the main cascades for the initiation, progression, and recurrence of most human malignancies. As an indispensable coreceptor for the signaling transduction of the canonical Wnt/ß-catenin pathway, LRP5 is up-regulated and exerts a carcinogenic role in most types of cancer. However, its expression level and role in gastric cancer (GC) has not been clearly elucidated. The current work showed that LRP5 was overexpressed in GC tissues and the expression of LRP5 was positively associated with the advanced clinical stages and poor prognosis. Ectopic expression of LRP5 enhanced the proliferation, invasiveness, and drug resistance of GC cells in vitro, and accelerated the tumor growth in nude mice, through activating the canonical Wnt/ß-catenin signaling pathway and up-regulating aerobic glycolysis, thus increasing the energy supply for GC cells. Additionally, the expression of LRP5 and glycolysis-related genes showed an obviously positive correlation in GC tissues. By contrast, the exact opposite results were observed when the endogenous LRP5 was silenced in GC cells. Collectively, these results not only reveal the carcinogenic role of LRP5 during GC development through activating the canonical Wnt/ß-catenin and glycolysis pathways, but also provide a valuable candidate for the diagnosis and treatment of human GC.


Asunto(s)
Proteína-5 Relacionada con Receptor de Lipoproteína de Baja Densidad , Neoplasias Gástricas , Vía de Señalización Wnt , Animales , Carcinogénesis , Línea Celular Tumoral , Proliferación Celular/genética , Glucólisis , Proteína-5 Relacionada con Receptor de Lipoproteína de Baja Densidad/genética , Ratones , Ratones Desnudos , Neoplasias Gástricas/patología , beta Catenina/metabolismo
12.
Curr Atheroscler Rep ; 25(10): 653-662, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37736845

RESUMEN

PURPOSE OF REVIEW: Transintestinal cholesterol excretion (TICE) is a non-biliary pathway that excretes excess cholesterol from the body through feces. This article focuses on the research progress of the TICE pathway in the last few years, including the discovery process of the TICE pathway, its molecular mechanism, and potential clinical applications. RECENT FINDINGS: Cholesterol homeostasis is vital for cardiovascular diseases, stroke, and neurodegenerative diseases. Beyond the cholesterol excretion via hepatobiliary pathway, TICE contributes significantly to reverse cholesterol transport ex vivo and in vivo. Nuclear receptors are ligand-activated transcription factors that regulate cholesterol metabolism. The farnesoid X receptor (FXR) and liver X receptor (LXR) activated, respectively, by oxysterols and bile acids promote intestinal cholesterol secretion through ABCG5/G8. Nutrient regulators and intestinal flora also modulate cholesterol secretion through the TICE pathway. TICE allows direct elimination of plasma cholesterol, which may provide an attractive therapeutic targets. TICE pathway may provide a potential target to stimulate cholesterol elimination and reduce the risk of cardiovascular diseases.

13.
Microbiol Immunol ; 67(3): 129-141, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36540014

RESUMEN

Osteoarthritis (OA) is a degenerative disease that occurs mostly in the elderly, and its specific pathogenesis is still unknown, but recent studies have found that circular RNA generally display aberrant expression in OA. Our study explored the expression characteristics and mechanism of action of circ-NT5C2 in OA. Circ-NT5C2, microRNA-142-5p (miR-142-5p), and nicotinamide phosphoribosyltransferase (NAMPT) mRNA levels were measured using RT-qPCR. Western blot was employed to assess the protein level of NAMPT and extracellular matrix (ECM) production-related markers. The viability, proliferation, apoptosis and inflammation were examined using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay, 5-ethynyl-2'-deoxyuridine (EdU) assay, flow cytometry, and enzyme-linked immunosorbent assay, respectively. Relationship between miR-142-5p and circ-NT5C2 or NAMPT was demonstrated by dual-luciferase reporter system and RNA immunoprecipitation assay. We reported that circ-NT5C2 and NAMPT were greatly upregulated, and miR-142-5p level was constrained in OA tissues and in a cell model. Circ-NT5C2 silencing alleviated IL-1ß-induced inhibitory effects on chondrocyte proliferation and ECM generation, meanwhile the promotional role of IL-1ß on chondrocyte apoptosis and inflammation was also weakened. The targeting relationship of miR-142-5p with either circ-NT5C2 or NAMPT was confirmed. Knockdown of miR-142-5p reversed the suppressive effects of circ-NT5C2 silencing on the OA progression in vitro, and NAMPT overexpression also attenuated the effects of miR-142-5p upregulation in an OA cell model. Collectively, circ-NT5C2 accelerated the OA process by targeting the miR-142-5p/NAMPT axis. This study provides valuable information to find a better treatment for OA.


Asunto(s)
5'-Nucleotidasa , Interleucina-1beta , MicroARNs , Nicotinamida Fosforribosiltransferasa , Osteoartritis , Anciano , Humanos , 5'-Nucleotidasa/genética , Apoptosis/genética , Inflamación/genética , Interleucina-1beta/genética , MicroARNs/genética , Nicotinamida Fosforribosiltransferasa/genética , Osteoartritis/genética
14.
Nature ; 544(7651): 460-464, 2017 04 27.
Artículo en Inglés | MEDLINE | ID: mdl-28397822

RESUMEN

Next-generation high-performance structural materials are required for lightweight design strategies and advanced energy applications. Maraging steels, combining a martensite matrix with nanoprecipitates, are a class of high-strength materials with the potential for matching these demands. Their outstanding strength originates from semi-coherent precipitates, which unavoidably exhibit a heterogeneous distribution that creates large coherency strains, which in turn may promote crack initiation under load. Here we report a counterintuitive strategy for the design of ultrastrong steel alloys by high-density nanoprecipitation with minimal lattice misfit. We found that these highly dispersed, fully coherent precipitates (that is, the crystal lattice of the precipitates is almost the same as that of the surrounding matrix), showing very low lattice misfit with the matrix and high anti-phase boundary energy, strengthen alloys without sacrificing ductility. Such low lattice misfit (0.03 ± 0.04 per cent) decreases the nucleation barrier for precipitation, thus enabling and stabilizing nanoprecipitates with an extremely high number density (more than 1024 per cubic metre) and small size (about 2.7 ± 0.2 nanometres). The minimized elastic misfit strain around the particles does not contribute much to the dislocation interaction, which is typically needed for strength increase. Instead, our strengthening mechanism exploits the chemical ordering effect that creates backstresses (the forces opposing deformation) when precipitates are cut by dislocations. We create a class of steels, strengthened by Ni(Al,Fe) precipitates, with a strength of up to 2.2 gigapascals and good ductility (about 8.2 per cent). The chemical composition of the precipitates enables a substantial reduction in cost compared to conventional maraging steels owing to the replacement of the essential but high-cost alloying elements cobalt and titanium with inexpensive and lightweight aluminium. Strengthening of this class of steel alloy is based on minimal lattice misfit to achieve maximal precipitate dispersion and high cutting stress (the stress required for dislocations to cut through coherent precipitates and thus produce plastic deformation), and we envisage that this lattice misfit design concept may be applied to many other metallic alloys.


Asunto(s)
Precipitación Química , Nanopartículas/química , Nanotecnología , Acero/química , Aluminio/química , Cobalto/química , Aleaciones Dentales/química , Elasticidad , Ensayo de Materiales , Microscopía Electrónica de Transmisión de Rastreo , Nanopartículas/ultraestructura , Acero/economía , Sincrotrones , Resistencia a la Tracción , Titanio/química , Tomografía
15.
J Comput Assist Tomogr ; 47(1): 31-37, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36668979

RESUMEN

OBJECTIVE: This study aimed to explore the feasibility and predictive value for local tumor progression (LTP) of the computed tomography (CT)-CT image fusion method versus side-by-side method to assess ablative margin (AM) in hepatocellular carcinoma ≥3 cm in diameter. MATERIALS AND METHODS: We selected patients with hepatocellular carcinoma ≥3 cm in diameter who underwent microwave ablation and had complete tumor ablation. We used the CT-CT image fusion method and side-by-side method to assess AM separately and divided the lesions into 3 groups: group I, minimum ablative margin (min-AM) <0 mm (the ablation zone did not fully cover the tumor); group II, 0 mm ≤ min-AM <5 mm; and group III, min-AM ≥5 mm. RESULTS: A total of 71 patients involving 71 lesions were included. The κ coefficient for the agreement between the CT-CT image fusion method and the side-by-side method in assessing min-AM was 0.14 (P = 0.028). Cumulative LTP rate was significantly different between groups by min-AM from the CT-CT image fusion method (P < 0.05) but not by min-AM from the side-by-side method (P = 0.807). Seventeen of the 20 LTP lesions were located at min-AM on fused CT images, with consistency rate of 85%. CONCLUSIONS: Compared with the side-by-side method, the CT-CT image fusion method is more accurate in assessing the AM of eccentrically ablated lesions and shows better predictive value for LTP. The min-AM based on CT-CT image fusion assessment is an important influencing factor for LTP.


Asunto(s)
Carcinoma Hepatocelular , Ablación por Catéter , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/diagnóstico por imagen , Carcinoma Hepatocelular/cirugía , Carcinoma Hepatocelular/patología , Neoplasias Hepáticas/diagnóstico por imagen , Neoplasias Hepáticas/cirugía , Neoplasias Hepáticas/patología , Microondas/uso terapéutico , Ablación por Catéter/métodos , Tomografía Computarizada por Rayos X/métodos , Resultado del Tratamiento , Estudios Retrospectivos
16.
Angew Chem Int Ed Engl ; 62(41): e202310556, 2023 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-37632257

RESUMEN

Nitrogen-heterocycle-based covalent organic frameworks (COFs) are considered promising candidates for the overall photosynthesis of hydrogen peroxide (H2 O2 ). However, the effects of the relative nitrogen locations remain obscured and photocatalytic performances of COFs need to be further improved. Herein, a collection of COFs functionalized by various diazines including pyridazine, pyrimidine, and pyrazine have been judiciously designed and synthesized for photogeneration of H2 O2 without sacrificial agents. Compared with pyrimidine and pyrazine, pyridazine embedded in TpDz tends to stabilize endoperoxide intermediate species, leading toward the more efficient direct 2e- oxygen reduction reaction (ORR) pathway. Benefiting from the effective electron-hole separation, low charge transfer resistance, and high-efficiency ORR pathway, an excellent production rate of 7327 µmol g-1 h-1 and a solar-to-chemical conversion (SCC) value of 0.62 % has been achieved by TpDz, which ranks one of the best COF-based photocatalysts. This work might shed fresh light on the rational design of functional COFs targeting photocatalysts in H2 O2 production.

17.
J Cell Mol Med ; 26(4): 1095-1112, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34997691

RESUMEN

The overactivation of canonical Wnt/ß-catenin pathway and the maintenance of cancer stem cells (CSCs) are essential for the onset and malignant progression of most human cancers. However, their regulatory mechanism in colorectal cancer (CRC) has not yet been well demonstrated. Low-density lipoprotein receptor-related protein 5 (LRP5) has been identified as an indispensable co-receptor with frizzled family members for the canonical Wnt/ß-catenin signal transduction. Herein, we show that activation of LRP5 gene promotes CSCs-like phenotypes, including tumorigenicity and drug resistance in CRC cells, through activating the canonical Wnt/ß-catenin and IL-6/STAT3 signalling pathways. Clinically, the expression of LRP5 is upregulated in human CRC tissues and closely associated with clinical stages of patients with CRC. Further analysis showed silencing of endogenous LRP5 gene is sufficient to suppress the CSCs-like phenotypes of CRC through inhibiting these two pathways. In conclusion, our findings not only reveal a regulatory cross-talk between canonical Wnt/ß-catenin signalling pathway, IL-6/STAT3 signalling pathway and CD133-related stemness that promote the malignant behaviour of CRC, but also provide a valuable target for the diagnosis and treatment of CRC.


Asunto(s)
Neoplasias Colorrectales , Proteína-5 Relacionada con Receptor de Lipoproteína de Baja Densidad , Línea Celular Tumoral , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/patología , Resistencia a Antineoplásicos/genética , Humanos , Proteína-5 Relacionada con Receptor de Lipoproteína de Baja Densidad/genética , Células Madre Neoplásicas/metabolismo , Fenotipo , Vía de Señalización Wnt/genética , beta Catenina/genética , beta Catenina/metabolismo
18.
Curr Issues Mol Biol ; 44(11): 5788-5801, 2022 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-36421677

RESUMEN

Metabolic dysregulation of the retinal pigment epithelium (RPE) has been implicated in age-related macular degeneration (AMD). However, the molecular regulation of RPE metabolism remains unclear. RIP140 is known to affect oxidative metabolism and mitochondrial biogenesis by negatively controlling mitochondrial pathways regulated by PPAR-γ co-activator-1 α(PGC-1α). This study aims to disclose the effect of RIP140 on the RPE metabolic program in vitro and in vivo. RIP140 protein levels were assayed by Western blotting. Gene expression was tested using quantitative real-time PCR (qRT-PCR), ATP production, and glycogen concentration assays, and the release of inflammatory factors was analyzed by commercial kits. Mice photoreceptor function was measured by electroretinography (ERG). In ARPE-19 cells, RIP140 overexpression changed the expression of the key metabolic genes and lipid processing genes, inhibited mitochondrial ATP production, and enhanced glycogenesis. Moreover, RIP140 overexpression promoted the translocation of NF-κB and increased the expression and production of IL-1ß, IL-6, and TNF-α in ARPE-19 cells. Importantly, we also observed the overexpression of RIP140 through adenovirus delivery in rat retinal cells, which significantly decreased the amplitude of the a-wave and b-wave measured by ERG assay. Therapeutic strategies that modulate the activity of RIP140 could have clinical utility for the treatment of AMD in terms of preventing RPE degeneration.

19.
J Nanobiotechnology ; 20(1): 69, 2022 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-35123493

RESUMEN

Chemodynamic therapy (CDT) based on Fenton or Fenton-like reactions is an emerging cancer treatment that can both effectively fight cancer and reduce side effects on normal cells and tissues, and it has made important progress in cancer treatment. The catalytic efficiency of Fenton nanocatalysts(F-NCs) directly determines the anticancer effect of CDT. To learn more about this new type of therapy, this review summarizes the recent development of F-NCs that are responsive to tumor microenvironment (TME), and detailedly introduces their material design and action mechanism. Based on the deficiencies of them, some effective strategies to significantly improve the anticancer efficacy of F-NCs are highlighted, which mainly includes increasing the temperature and hydrogen peroxide concentration, reducing the pH, glutathione (GSH) content, and the dependence of F-NCs on acidic environment in the TME. It also discusses the differences between the effect of multi-mode therapy with external energy (light and ultrasound) and the single-mode therapy of CDT. Finally, the challenges encountered in the treatment process, the future development direction of F-NCs, and some suggestions are analyzed to promote CDT to enter the clinical stage in the near future.


Asunto(s)
Nanopartículas , Neoplasias , Catálisis , Línea Celular Tumoral , Humanos , Peróxido de Hidrógeno/química , Nanopartículas/química , Neoplasias/tratamiento farmacológico , Microambiente Tumoral
20.
Int J Mol Sci ; 24(1)2022 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-36613528

RESUMEN

Breast cancer is a major health threat and the second leading cause of cancer-related deaths in women worldwide. The detailed mechanisms involved in the initiation and progression of breast cancer remain unclear. In recent years, amounting evidence indicated that long non-coding RNAs (lncRNAs) played crucial roles in regulating various biological processes and malignancy tumors, including breast cancer. In this review, we briefly introduce the functions and underlying mechanisms by which lncRNAs are involved in breast cancer. We summarize the roles of the lncRNAs in regulating malignant behaviors of breast cancer, such as cell proliferation, migration and invasion, epithelial-mesenchymal transition (EMT), apoptosis, and drug resistance. Additionally, we also briefly summarize the roles of circular RNAs (circRNAs) in breast cancer carcinogenesis.


Asunto(s)
Neoplasias de la Mama , ARN Largo no Codificante , Humanos , Femenino , ARN Largo no Codificante/genética , Neoplasias de la Mama/genética , Carcinogénesis , ARN Circular/genética , Transición Epitelial-Mesenquimal/genética
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