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1.
Nature ; 608(7921): 62-68, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35922499

RESUMEN

Additive manufacturing produces net-shaped components layer by layer for engineering applications1-7. The additive manufacture of metal alloys by laser powder bed fusion (L-PBF) involves large temperature gradients and rapid cooling2,6, which enables microstructural refinement at the nanoscale to achieve high strength. However, high-strength nanostructured alloys produced by laser additive manufacturing often have limited ductility3. Here we use L-PBF to print dual-phase nanolamellar high-entropy alloys (HEAs) of AlCoCrFeNi2.1 that exhibit a combination of a high yield strength of about 1.3 gigapascals and a large uniform elongation of about 14 per cent, which surpasses those of other state-of-the-art additively manufactured metal alloys. The high yield strength stems from the strong strengthening effects of the dual-phase structures that consist of alternating face-centred cubic and body-centred cubic nanolamellae; the body-centred cubic nanolamellae exhibit higher strengths and higher hardening rates than the face-centred cubic nanolamellae. The large tensile ductility arises owing to the high work-hardening capability of the as-printed hierarchical microstructures in the form of dual-phase nanolamellae embedded in microscale eutectic colonies, which have nearly random orientations to promote isotropic mechanical properties. The mechanistic insights into the deformation behaviour of additively manufactured HEAs have broad implications for the development of hierarchical, dual- and multi-phase, nanostructured alloys with exceptional mechanical properties.

2.
Nature ; 595(7866): 245-249, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-34234333

RESUMEN

Single-phase high- and medium-entropy alloys with face-centred cubic (fcc) structure can exhibit high tensile ductility1,2 and excellent toughness2,3, but their room-temperature strengths are low1-3. Dislocation obstacles such as grain boundaries4, twin boundaries5, solute atoms6 and precipitates7-9 can increase strength. However, with few exceptions8-11, such obstacles tend to decrease ductility. Interestingly, precipitates can also hinder phase transformations12,13. Here, using a model, precipitate-strengthened, Fe-Ni-Al-Ti medium-entropy alloy, we demonstrate a strategy that combines these dual functions in a single alloy. The nanoprecipitates in our alloy, in addition to providing conventional strengthening of the matrix, also modulate its transformation from fcc-austenite to body-centred cubic (bcc) martensite, constraining it to remain as metastable fcc after quenching through the transformation temperature. During subsequent tensile testing, the matrix progressively transforms to bcc-martensite, enabling substantial increases in strength, work hardening and ductility. This use of nanoprecipitates exploits synergies between precipitation strengthening and transformation-induced plasticity, resulting in simultaneous enhancement of tensile strength and uniform elongation. Our findings demonstrate how synergistic deformation mechanisms can be deliberately activated, exactly when needed, by altering precipitate characteristics (such as size, spacing, and so on), along with the chemical driving force for phase transformation, to optimize strength and ductility.

3.
Proc Natl Acad Sci U S A ; 121(21): e2401079121, 2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38739800

RESUMEN

Homomeric dimerization of metabotropic glutamate receptors (mGlus) is essential for the modulation of their functions and represents a promising avenue for the development of novel therapeutic approaches to address central nervous system diseases. Yet, the scarcity of detailed molecular and energetic data on mGlu2 impedes our in-depth comprehension of their activation process. Here, we employ computational simulation methods to elucidate the activation process and key events associated with the mGlu2, including a detailed analysis of its conformational transitions, the binding of agonists, Gi protein coupling, and the guanosine diphosphate (GDP) release. Our results demonstrate that the activation of mGlu2 is a stepwise process and several energy barriers need to be overcome. Moreover, we also identify the rate-determining step of the mGlu2's transition from the agonist-bound state to its active state. From the perspective of free-energy analysis, we find that the conformational dynamics of mGlu2's subunit follow coupled rather than discrete, independent actions. Asymmetric dimerization is critical for receptor activation. Our calculation results are consistent with the observation of cross-linking and fluorescent-labeled blot experiments, thus illustrating the reliability of our calculations. Besides, we also identify potential key residues in the Gi protein binding position on mGlu2, mGlu2 dimer's TM6-TM6 interface, and Gi α5 helix by the change of energy barriers after mutation. The implications of our findings could lead to a more comprehensive grasp of class C G protein-coupled receptor activation.


Asunto(s)
Receptores de Glutamato Metabotrópico , Receptores de Glutamato Metabotrópico/metabolismo , Receptores de Glutamato Metabotrópico/química , Humanos , Multimerización de Proteína , Simulación de Dinámica Molecular , Conformación Proteica , Unión Proteica
4.
Nature ; 585(7823): 63-67, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32879503

RESUMEN

Rechargeable lithium-ion batteries with high energy density that can be safely charged and discharged at high rates are desirable for electrified transportation and other applications1-3. However, the sub-optimal intercalation potentials of current anodes result in a trade-off between energy density, power and safety. Here we report that disordered rock salt4,5 Li3+xV2O5 can be used as a fast-charging anode that can reversibly cycle two lithium ions at an average voltage of about 0.6 volts versus a Li/Li+ reference electrode. The increased potential compared to graphite6,7 reduces the likelihood of lithium metal plating if proper charging controls are used, alleviating a major safety concern (short-circuiting related to Li dendrite growth). In addition, a lithium-ion battery with a disordered rock salt Li3V2O5 anode yields a cell voltage much higher than does a battery using a commercial fast-charging lithium titanate anode or other intercalation anode candidates (Li3VO4 and LiV0.5Ti0.5S2)8,9. Further, disordered rock salt Li3V2O5 can perform over 1,000 charge-discharge cycles with negligible capacity decay and exhibits exceptional rate capability, delivering over 40 per cent of its capacity in 20 seconds. We attribute the low voltage and high rate capability of disordered rock salt Li3V2O5 to a redistributive lithium intercalation mechanism with low energy barriers revealed via ab initio calculations. This low-potential, high-rate intercalation reaction can be used to identify other metal oxide anodes for fast-charging, long-life lithium-ion batteries.

5.
Nature ; 565(7739): E8, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30568306

RESUMEN

Change history: In this Letter, owing to a production error, all the data points (except the two points for O-2 and N-2, respectively) were missing in Fig. 1b. The figure has been corrected online.

6.
Proteins ; 92(6): 705-719, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38183172

RESUMEN

The omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) characterized by 30 mutations in its spike protein, has rapidly spread worldwide since November 2021, significantly exacerbating the ongoing COVID-19 pandemic. In order to investigate the relationship between these mutations and the variant's high transmissibility, we conducted a systematic analysis of the mutational effect on spike-angiotensin-converting enzyme-2 (ACE2) interactions and explored the structural/energy correlation of key mutations, utilizing a reliable coarse-grained model. Our study extended beyond the receptor-binding domain (RBD) of spike trimer through comprehensive modeling of the full-length spike trimer rather than just the RBD. Our free-energy calculation revealed that the enhanced binding affinity between the spike protein and the ACE2 receptor is correlated with the increased structural stability of the isolated spike protein, thus explaining the omicron variant's heightened transmissibility. The conclusion was supported by our experimental analyses involving the expression and purification of the full-length spike trimer. Furthermore, the energy decomposition analysis established those electrostatic interactions make major contributions to this effect. We categorized the mutations into four groups and established an analytical framework that can be employed in studying future mutations. Additionally, our calculations rationalized the reduced affinity of the omicron variant towards most available therapeutic neutralizing antibodies, when compared with the wild type. By providing concrete experimental data and offering a solid explanation, this study contributes to a better understanding of the relationship between theories and observations and lays the foundation for future investigations.


Asunto(s)
Enzima Convertidora de Angiotensina 2 , COVID-19 , Mutación , Unión Proteica , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , SARS-CoV-2/genética , SARS-CoV-2/metabolismo , SARS-CoV-2/química , Glicoproteína de la Espiga del Coronavirus/química , Glicoproteína de la Espiga del Coronavirus/genética , Glicoproteína de la Espiga del Coronavirus/metabolismo , COVID-19/virología , COVID-19/transmisión , Humanos , Enzima Convertidora de Angiotensina 2/metabolismo , Enzima Convertidora de Angiotensina 2/química , Enzima Convertidora de Angiotensina 2/genética , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/química , Simulación de Dinámica Molecular , Termodinámica , Modelos Moleculares
7.
Breast Cancer Res ; 26(1): 94, 2024 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-38844963

RESUMEN

BACKGROUND: RNA m5C methylation has been extensively implicated in the occurrence and development of tumors. As the main methyltransferase, NSUN2 plays a crucial regulatory role across diverse tumor types. However, the precise impact of NSUN2-mediated m5C modification on breast cancer (BC) remains unclear. Our study aims to elucidate the molecular mechanism underlying how NSUN2 regulates the target gene HGH1 (also known as FAM203) through m5C modification, thereby promoting BC progression. Additionally, this study targets at preliminarily clarifying the biological roles of NSUN2 and HGH1 in BC. METHODS: Tumor and adjacent tissues from 5 BC patients were collected, and the m5C modification target HGH1 in BC was screened through RNA sequencing (RNA-seq) and single-base resolution m5C methylation sequencing (RNA-BisSeq). Methylation RNA immunoprecipitation-qPCR (MeRIP-qPCR) and RNA-binding protein immunoprecipitation-qPCR (RIP-qPCR) confirmed that the methylation molecules NSUN2 and YBX1 specifically recognized and bound to HGH1 through m5C modification. In addition, proteomics, co-immunoprecipitation (co-IP), and Ribosome sequencing (Ribo-Seq) were used to explore the biological role of HGH1 in BC. RESULTS: As the main m5C methylation molecule, NSUN2 is abnormally overexpressed in BC and increases the overall level of RNA m5C. Knocking down NSUN2 can inhibit BC progression in vitro or in vivo. Combined RNA-seq and RNA-BisSeq analysis identified HGH1 as a potential target of abnormal m5C modifications. We clarified the mechanism by which NSUN2 regulates HGH1 expression through m5C modification, a process that involves interactions with the YBX1 protein, which collectively impacts mRNA stability and protein synthesis. Furthermore, this study is the first to reveal the binding interaction between HGH1 and the translation elongation factor EEF2, providing a comprehensive understanding of its ability to regulate transcript translation efficiency and protein synthesis in BC cells. CONCLUSIONS: This study preliminarily clarifies the regulatory role of the NSUN2-YBX1-m5C-HGH1 axis from post-transcriptional modification to protein translation, revealing the key role of abnormal RNA m5C modification in BC and suggesting that HGH1 may be a new epigenetic biomarker and potential therapeutic target for BC.


Asunto(s)
Neoplasias de la Mama , Progresión de la Enfermedad , Regulación Neoplásica de la Expresión Génica , Metiltransferasas , Estabilidad del ARN , Proteína 1 de Unión a la Caja Y , Animales , Femenino , Humanos , Ratones , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Neoplasias de la Mama/metabolismo , Línea Celular Tumoral , Proliferación Celular , Metilación , Metiltransferasas/metabolismo , Metiltransferasas/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Proteína 1 de Unión a la Caja Y/metabolismo , Proteína 1 de Unión a la Caja Y/genética , Péptidos y Proteínas de Señalización Intracelular/genética , Péptidos y Proteínas de Señalización Intracelular/metabolismo
8.
Nature ; 563(7732): 546-550, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30429610

RESUMEN

Oxygen, one of the most abundant elements on Earth, often forms an undesired interstitial impurity or ceramic phase (such as an oxide particle) in metallic materials. Even when it adds strength, oxygen doping renders metals brittle1-3. Here we show that oxygen can take the form of ordered oxygen complexes, a state in between oxide particles and frequently occurring random interstitials. Unlike traditional interstitial strengthening4,5, such ordered interstitial complexes lead to unprecedented enhancement in both strength and ductility in compositionally complex solid solutions, the so-called high-entropy alloys (HEAs)6-10. The tensile strength is enhanced (by 48.5 ± 1.8 per cent) and ductility is substantially improved (by 95.2 ± 8.1 per cent) when doping a model TiZrHfNb HEA with 2.0 atomic per cent oxygen, thus breaking the long-standing strength-ductility trade-off11. The oxygen complexes are ordered nanoscale regions within the HEA characterized by (O, Zr, Ti)-rich atomic complexes whose formation is promoted by the existence of chemical short-range ordering among some of the substitutional matrix elements in the HEAs. Carbon has been reported to improve strength and ductility simultaneously in face-centred cubic HEAs12, by lowering the stacking fault energy and increasing the lattice friction stress. By contrast, the ordered interstitial complexes described here change the dislocation shear mode from planar slip to wavy slip, and promote double cross-slip and thus dislocation multiplication through the formation of Frank-Read sources (a mechanism explaining the generation of multiple dislocations) during deformation. This ordered interstitial complex-mediated strain-hardening mechanism should be particularly useful in Ti-, Zr- and Hf-containing alloys, in which interstitial elements are highly undesirable owing to their embrittlement effects, and in alloys where tuning the stacking fault energy and exploiting athermal transformations13 do not lead to property enhancement. These results provide insight into the role of interstitial solid solutions and associated ordering strengthening mechanisms in metallic materials.

9.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 55(2): 469-474, 2024 Mar 20.
Artículo en Zh | MEDLINE | ID: mdl-38645865

RESUMEN

Craniomaxillofacial development involves a series of highly ordered temporal-spatial cellular differentiation processes in which a variety of cell signaling factors, such as fibroblast growth factors, play important regulatory roles. As a classic fibroblast growth factor, fibroblast growth factor 7 (FGF7) serves a wide range of regulatory functions. Previous studies have demonstrated that FGF7 regulates the proliferation and migration of epithelial cells, protects them, and promotes their repair. Furthermore, recent findings indicate that epithelial cells are not the only ones subjected to the broad and powerful regulatory capacity of FGF7. It has potential effects on skeletal system development as well. In addition, FGF7 plays an important role in the development of craniomaxillofacial organs, such as the palate, the eyes, and the teeth. Nonetheless, the role of FGF7 in oral craniomaxillofacial development needs to be further elucidated. In this paper, we summarized the published research on the role of FGF7 in oral craniomaxillofacial development to demonstrate the overall understanding of FGF7 and its potential functions in oral craniomaxillofacial development.


Asunto(s)
Factor 7 de Crecimiento de Fibroblastos , Humanos , Factor 7 de Crecimiento de Fibroblastos/metabolismo , Factor 7 de Crecimiento de Fibroblastos/genética , Animales , Cráneo/crecimiento & desarrollo , Cráneo/metabolismo , Desarrollo Maxilofacial/fisiología , Diente/metabolismo , Diente/crecimiento & desarrollo
10.
Zhongguo Zhong Yao Za Zhi ; 49(1): 88-99, 2024 Jan.
Artículo en Zh | MEDLINE | ID: mdl-38403342

RESUMEN

Anemarrhena asphodeloides is a common medicinal material used in clinical prescriptions and Chinese patent medicine. In this study, the Illumina platform was used to obtain the chloroplast genome sequences of seven kinds of A. asphodeloides from different areas. The specific DNA barcodes were screened by comparative genomics analysis, and the DNA barcodes were used to identify the germplasm resources and analyze the genetic diversity of A. asphodeloides samples from different areas in China. All the seven chloroplast genomes had a ring structure. The total length was 156 801-156 930 bp, and 113 genes were annotated, including 79 protein-coding genes, 30 tRNA genes, and four rRNA genes. The comparative genomics analysis showed that rps16, trnG-GCC, atpF, rpoB, ycf3, rpl16, ndhF, trnS-GCU_trnG-GCC, petN-psbM, and ndhF-rpl32 were potential candidates for specific DNA barcodes of A. asphodeloides. In this study, the second intron of ycf3 and atpF intron sequences with a sequence length of 700-800 bp and easy amplification were selected for polymerase chain reaction(PCR) amplification and sequencing of 594 samples from 26 areas. The sequence analysis showed that six and eight haplotypes of ycf3 and atpF sequences could be identified, respectively, and 17 haplotypes could be identified by combined analysis of the two sequences, which were named Hap1-Hap17. The haplotype diversity(H_d), nucleotide diversity(P_i), and genetic distance of A. asphodeloides in 26 populations were 0.68, 0.93×10~(-3), and 0-0.003 1, respectively, indicating that the genetic diversity within the species of A. asphodeloides is rich. The intermediary adjacent network analysis showed that Hap5 was the oldest haplotype, which was mainly distributed in Yixian county of Baoding, Hebei province, Hequ county of Xinzhou, Shanxi province, and Xiangfen county of Linfen, Shanxi province. This study has important guiding significance for the identification of A. asphodeloides species, the protection and development of germplasm resources, and the identification of production areas, and it provides a research basis for further revealing the genetic evolution law of A. asphodeloides.


Asunto(s)
Anemarrhena , Anemarrhena/química , Código de Barras del ADN Taxonómico , Variación Genética , China , Filogenia
11.
J Am Chem Soc ; 145(18): 10208-10219, 2023 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-37098172

RESUMEN

High-voltage LiCoO2 (LCO) attracts great interest because of its large specific capacity, but it suffers from oxygen release, structural degradation, and quick capacity drop. These daunting issues root from the inferior thermodynamics and kinetics of the triggered oxygen anion redox (OAR) at high voltages. Herein, a tuned redox mechanism with almost only Co redox is demonstrated by atomically engineered high-spin LCO. The high-spin Co network reduces the Co/O band overlap, eliminates the adverse phase transition of O3 → H1-3, delays the exceeding of the O 2p band over the Fermi level, and suppresses excessive O → Co charge transfer at high voltages. This function intrinsically promotes Co redox and restrains O redox, fundamentally addressing the issues of O2 release and coupled detrimental Co reduction. Moreover, the chemomechanical heterogeneity caused by different kinetics of Co/O redox centers and the inferior rate performance limited by slow O redox kinetics is simultaneously improved owing to the suppression of slow OAR and the excitation of fast Co redox. The modulated LCO delivers ultrahigh rate capacities of 216 mAh g-1 (1C) and 195 mAh g-1(5C), as well as high capacity retentions of 90.4% (@100 cycles) and 86.9% (@500 cycles). This work sheds new light on the design for a wide range of O redox cathodes.

12.
Mol Cancer ; 22(1): 81, 2023 05 09.
Artículo en Inglés | MEDLINE | ID: mdl-37161388

RESUMEN

BACKGROUND: RNA 5-methylcytosine (m5C) modification plays critical roles in the pathogenesis of various tumors. However, the function and molecular mechanism of RNA m5C modification in tumor drug resistance remain unclear. METHODS: The correlation between RNA m5C methylation, m5C writer NOP2/Sun RNA methyltransferase family member 2 (NSUN2) and EGFR-TKIs resistance was determined in non-small-cell lung cancer (NSCLC) cell lines and patient samples. The effects of NSUN2 on EGFR-TKIs resistance were investigated by gain- and loss-of-function assays in vitro and in vivo. RNA-sequencing (RNA-seq), RNA bisulfite sequencing (RNA-BisSeq) and m5C methylated RNA immunoprecipitation-qPCR (MeRIP-qPCR) were performed to identify the target gene of NSUN2 involved in EGFR-TKIs resistance. Furthermore, the regulatory mechanism of NSUN2 modulating the target gene expression was investigated by functional rescue and puromycin incorporation assays. RESULTS: RNA m5C hypermethylation and NSUN2 were significantly correlated with intrinsic resistance to EGFR-TKIs. Overexpression of NSUN2 resulted in gefitinib resistance and tumor recurrence, while genetic inhibition of NSUN2 led to tumor regression and overcame intrinsic resistance to gefitinib in vitro and in vivo. Integrated RNA-seq and m5C-BisSeq analyses identified quiescin sulfhydryl oxidase 1 (QSOX1) as a potential target of aberrant m5C modification. NSUN2 methylated QSOX1 coding sequence region, leading to enhanced QSOX1 translation through m5C reader Y-box binding protein 1 (YBX1). CONCLUSIONS: Our study reveals a critical function of aberrant RNA m5C modification via the NSUN2-YBX1-QSOX1 axis in mediating intrinsic resistance to gefitinib in EGFR-mutant NSCLC.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Humanos , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/genética , Gefitinib/farmacología , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/genética , Recurrencia Local de Neoplasia , ARN , Receptores ErbB/genética , Proteína 1 de Unión a la Caja Y , Oxidorreductasas actuantes sobre Donantes de Grupos Sulfuro , Metiltransferasas/genética
13.
J Transl Med ; 21(1): 63, 2023 01 30.
Artículo en Inglés | MEDLINE | ID: mdl-36717891

RESUMEN

BACKGROUND: Circulating tumor DNA (ctDNA) detection following curative-intent surgery could directly reflect the presence of minimal residual disease, the ultimate cause of clinical recurrence. However, ctDNA is not postoperatively detected in ≥ 50% of patients with stage I-III colorectal cancer (CRC) who ultimately recur. Herein we sought to improve recurrence risk prediction by combining ctDNA with clinicopathological risk factors in stage I-III CRC. METHODS: Two independent cohorts, both consisting of early-stage CRC patients who underwent curative surgery, were included: (i) the discovery cohort (N = 124) with tumor tissues and postoperative plasmas for ctDNA determination; and (ii) the external validation cohort (N = 125) with available ctDNA results. In the discovery cohort, somatic variations in tumor tissues and plasmas were determined via a 733-gene and 127-gene next-generation sequencing panel, respectively. RESULTS: In the discovery cohort, 17 of 108 (15.7%) patients had detectable ctDNA. ctDNA-positive patients had a significantly high recurrence rate (76.5% vs. 16.5%, P < 0.001) and short recurrence-free survival (RFS; P < 0.001) versus ctDNA-negative patients. In addition to ctDNA status, the univariate Cox model identified pathologic stage, lymphovascular invasion, nerve invasion, and preoperative carcinoembryonic antigen level associated with RFS. We combined the ctDNA and clinicopathological risk factors (CTCP) to construct a model for recurrence prediction. A significantly higher recurrence rate (64.7% vs. 8.1%, P < 0.001) and worse RFS (P < 0.001) were seen in the high-risk patients classified by the CTCP model versus those in the low-risk patients. Receiver operating characteristic analysis demonstrated that the CTCP model outperformed ctDNA alone at recurrence prediction, which increased the sensitivity of 2 year RFS from 49.6% by ctDNA alone to 87.5%. Harrell's concordance index, calibration curve, and decision curve analysis also suggested that the CTCP model had good discrimination, consistency, and clinical utility. These results were reproduced in the validation cohort. CONCLUSION: Combining postoperative ctDNA and clinical risk may better predict recurrence than ctDNA alone for developing a personalized postoperative management strategy for CRC.


Asunto(s)
ADN Tumoral Circulante , Neoplasias Colorrectales , Humanos , ADN Tumoral Circulante/genética , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/cirugía , Neoplasias Colorrectales/patología , Biomarcadores de Tumor/genética , Curva ROC , Factores de Riesgo , Recurrencia Local de Neoplasia/genética , Recurrencia Local de Neoplasia/patología
14.
Phys Chem Chem Phys ; 25(29): 19358-19370, 2023 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-37439122

RESUMEN

Plasmonic photocatalysis has recently attracted much attention in enhancing the solar-to-chemical conversion efficiency (SCCE) owing to localized surface plasmon resonance (LSPR), whose energy can be synthetically varied from the ultraviolet through the visible to the near-infrared region. This wide variability is inaccessible by traditional semiconductor photocatalysts. However, for all-metal plasmonic photocatalysts, the photogenerated hot charge carriers have an ultrashort lifetime because of their rapid recombination. For most metal-semiconductor hybrid plasmonic photocatalysts, a large portion of plasmonic hot charge carriers is lost during transfer from the metal to the semiconductor because of the Schottky barrier formed at the metal-semiconductor interface. As a result, both types of plasmonic photocatalysts exhibit limited SCCEs. To overcome the aforementioned shortcomings, a new type of plasmonic photocatalyst, the Schottky-barrier-free plasmonic photocatalyst, has been proposed recently. This type of plasmonic photocatalyst not only possesses LSPR to generate abundant hot charge carriers, but is also Schottky-barrier-free so that the hot charge carriers can be utilized more sufficiently to drive redox reactions. In this perspective, we first discuss the different types of plasmonic photocatalysts using representative examples, then introduce Schottky-barrier-free plasmonic photocatalysts, and finally provide the major challenges and remaining questions of this new type of plasmonic photocatalyst. We believe this perspective will offer insight into the further development of plasmonic photocatalysis and the improvement of its SCCEs.

15.
Colorectal Dis ; 25(10): 2087-2092, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37612783

RESUMEN

AIM: The aim of this study was to investigate the efficacy of multiple perineal perforator flaps in repairing deep perineal defects after pelvic exenteration for locally advanced or recurrent rectal cancer. METHOD: We investigated the outcomes of eight patients whose repairs involved a novel method of using an internal pudendal artery perforator (IPAP) flap combined with an inferior gluteal artery perforator (IGAP) flap. RESULTS: There were four male and four female patients with a mean age of 56 years (36-72 years). Bilateral IPAP flaps combined with bilateral IGAP flaps were used in five patients, unilateral IPAP flaps combined with bilateral IGAP flaps were used in two patients and bilateral IPAP flaps were used in one patient. There were no functional limitations in daily activities during the 6-month follow-up period. CONCLUSION: Our study showed that using multiple perineal perforator flaps combined with lining repair is feasible for repairing deep perineal defects in patients who have undergone rectal cancer surgery that includes pelvic exenteration.


Asunto(s)
Exenteración Pélvica , Colgajo Perforante , Procedimientos de Cirugía Plástica , Neoplasias del Recto , Humanos , Masculino , Femenino , Persona de Mediana Edad , Neoplasias del Recto/cirugía , Perineo/cirugía , Colgajo Perforante/cirugía
16.
Sleep Breath ; 2023 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-37775619

RESUMEN

PURPOSE: Intermittent hypoxia (IH) is a hallmark of obstructive sleep apnea (OSA), which is related to tumorigenesis and progression. Although micro-ribonucleic acid-210-3p (miR-210-3p) is correlated with hypoxia-induced tumor development, its role in the relationship between IH and tumor function remains poorly understood. The present work focused on elucidating the molecular mechanism through which miR-210-3p drives tumor progression under IH. METHODS: MiR-210-3p levels were quantified within tumor samples from patients with lung adenocarcinoma who had or did not have OSA. Correlations between miR-210-3p and polysomnographic variables were analyzed. For in vitro experiments, miR-210-3p was inhibited or overexpressed via transfection under IH conditions. Cell viability, growth, invasion and migration assays were carried out. For in vivo modeling of IH using mouse xenografts, a miR-210-3p antagomir was intratumorally injected, tumor biological behaviors were evaluated, and reverse transcription-quantitative polymerase chain reaction (RT-qPCR), immunohistochemistry and western blot were carried out for detecting miR-210-3p and E2F transcription factor 3 (E2F3) expression. RESULTS: For patients with lung adenocarcinoma and OSA, high miR-210-3p levels showed positive relation to polysomnographic variables, such as oxygen desaturation index, apnea-hypopnea index, and proportion of total sleep time with oxygen saturation in arterial blood < 90%. IH enhanced tumor viability, proliferation, migration, and invasion, downregulated E2F3 expression, and increased miR-210-3-p levels. miR-210-3p overexpression induced similar changes. These changes were reversed by miR-210-3p inhibition in vitro or miR-210-3p antagomir through intratumoral injection in vivo. CONCLUSIONS: IH-induced tumor development is driven through miR-210-3p by E2F3 suppression. MiR-210-3p represents a potential therapeutic target among patients with concomitant cancer and OSA.

17.
Proc Natl Acad Sci U S A ; 117(52): 33061-33071, 2020 Dec 29.
Artículo en Inglés | MEDLINE | ID: mdl-33376215

RESUMEN

Engineering neutron diffraction can nondestructively and noninvasively probe stress, strain, temperature, and phase evolutions deep within bulk materials. In this work, we demonstrate operando lattice strain measurement of internal combustion engine components by neutron diffraction. A modified commercial generator engine was mounted in the VULCAN diffractometer at the Spallation Neutron Source, and the lattice strains in both the cylinder block and head were measured under static nonfiring conditions as well as steady state and cyclic transient operation. The dynamic temporal response of the lattice strain change during transient operation was resolved in two locations by asynchronous stroboscopic neutron diffraction. We demonstrated that operando neutron measurements can allow for understanding of how materials behave throughout operational engineering devices. This study opens a pathway for the industrial and academic communities to better understand the complexities of material behavior during the operation of internal combustion engines and other real-scale devices and systems and to leverage techniques developed here for future investigations of numerous new platforms and alloys.

18.
J Anesth ; 37(6): 896-904, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37707572

RESUMEN

PURPOSE: Patients with robot-assisted laparoscopic radical prostatectomy (RALP) need to be placed in Trendelenburg position, which results in cranial displacement of the diaphragm and decreases functional residual capacity and pulmonary compliance. Positive end-expiratory pressure (PEEP) can increase ventilation in the dorsal area, reduce the occurrence of atelectasis and improve oxygenation. However, due to individual differences, inappropriate PEEP will cause lung injury and even hemodynamic instability. Therefore, our study is to evaluate the efficacy of individualized PEEP in RALP. METHODS: We randomly recruited 48 patients and divided them into driving pressure-guided individualized PEEP group (P group, individualized PEEP) or traditional lung-protective ventilation strategy group (C group, tidal volume 8 mL/kg combined with PEEP of 5cmH2O). The primary outcome was the PaO2/FiO2 before extubation. The secondary outcomes included individualized PEEP values in the P group, the results of arterial blood gas analysis, respiratory mechanics parameters and vital sign parameters. Other measurements included intraoperative vasoactive drug dosage, length of stay, postoperative SpO2, leukocyte count, temperature, serum inflammatory factors and soluble receptor for advanced glycation end products (sRAGE). RESULTS: Individualized PEEP improved the PaO2/FiO2 before extubation (P = 0.034) and decreased driving pressure (P = 0.011). The PEEP valued in the P group was 14 [10-14] cmH2O. The lung compliance of the P group was significantly higher than that in the C group (P = 0.013). There was no significant difference in other measurements. CONCLUSIONS: Individualized PEEP could improve PaO2/FiO2 in patients who underwent RALP and do not increase the dosage of intraoperative vasoactive drug and the release of inflammatory factors. TRIAL REGISTRATION: www.chictr.org.cn (registration no. ChiCTR2100047271).


Asunto(s)
Laparoscopía , Robótica , Masculino , Humanos , Respiración con Presión Positiva/métodos , Pulmón , Prostatectomía/métodos , Laparoscopía/métodos
19.
Sheng Li Xue Bao ; 75(6): 918-926, 2023 Dec 25.
Artículo en Zh | MEDLINE | ID: mdl-38151353

RESUMEN

Aging is a crucial factor influencing postural stability control and contributing to frequent falls, yet its underlying mechanisms remain incompletely understood. This study aims to explore the effects of aging on postural stability control by comparing differences in postural stability and node strength of electroencephalogram (EEG) brain network between elderly and young people under the conditions of congruent and incongruent visual-vestibular sensory inputs. Eighteen elderly volunteers without neuromuscular disorders and eighteen young individuals participated in the present study. Virtual reality (VR) technology was employed to manipulate visual rotation stimuli (clockwise and counterclockwise), and a horizontal rotating platform was used for vestibular rotation stimuli (clockwise). Based on the directional disparity of sensory input in the horizontal plane, visual-vestibular input consistency was categorized as congruent and incongruent. Postural stability was assessed by the center of pressure (COP) trajectory, and EEG signals were collected and analyzed using directed network analysis to observe EEG brain network node connectivity strength. The results revealed that, under conditions of incongruent visual-vestibular sensory inputs, the elderly exhibited significantly inferior postural stability performance in terms of COP anterior-posterior (Y-axial) sway speed, total path length, anterior-posterior and medial-lateral sample entropy, compared to the young adults. Moreover, the node connectivity strength of visual cortex in the elderly was notably higher, while node connectivity strength of superior temporal cortex was significantly lower than that in the young adults. These findings suggest that the elderly have a heightened reliance on visual information in postural control and an impaired ability to cope with sensory conflicts arising from incongruent visual-vestibular sensory inputs, leading to compromised postural stability. The outcomes of this study hold significant implications for future assessments of balance function in the elder and fall prevention trainings.


Asunto(s)
Equilibrio Postural , Postura , Adulto Joven , Humanos , Anciano , Adolescente , Envejecimiento , Encéfalo
20.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 54(6): 1294-1299, 2023 Nov 20.
Artículo en Zh | MEDLINE | ID: mdl-38162082

RESUMEN

Ferroptosis, a newly-discovered mode of programmed cell death, is closely associated with the development of various diseases throughout the human body, such as tumors of the digestive system, ischemia-reperfusion injury, osteoarthropathy, etc. Therefore, ferroptosis has become a hot research topic in many fields of study in recent years, providing new ideas for the prevention and treatment of relevant diseases. Among them, structural lesions in osteoarthropathies involving articular cartilage, subchondral bone, and synovial tissue have been found to be associated with iron overload, as well as oxidative stress, which suggests that inhibition of ferroptosis in relevant joint tissue cells may have a positive effect in halting the development of osteoarthropathy. Herein, focusing on ferroptosis and osteoarthropathy, we summarized the research developments in mechanisms related to iron metabolism and ferroptosis, analyzed the impact of ferroptosis on the pathogenesis and development of osteoarthropathy, and proposed new ideas for medication therapies of osteoarthropathy, taking into account the latest research findings.


Asunto(s)
Cartílago Articular , Ferroptosis , Daño por Reperfusión , Humanos , Apoptosis , Estrés Oxidativo
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