Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 122
Filtrar
1.
Proc Natl Acad Sci U S A ; 121(39): e2408974121, 2024 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-39292742

RESUMEN

Metamaterial has been captivated a popular notion, offering photonic functionalities beyond the capabilities of natural materials. Its desirable functionality primarily relies on well-controlled conditions such as structural resonance, dispersion, geometry, filling fraction, external actuation, etc. However, its fundamental building blocks-meta-atoms-still rely on naturally occurring substances. Here, we propose and validate the concept of gradient and reversible atomic-engineered metamaterials (GRAM), which represents a platform for continuously tunable solid metaphotonics by atomic manipulation. GRAM consists of an atomic heterogenous interface of amorphous host and noble metals at the bottom, and the top interface was designed to facilitate the reversible movement of foreign atoms. Continuous and reversible changes in GRAM's refractive index and atomic structures are observed in the presence of a thermal field. We achieve multiple optical states of GRAM at varying temperature and time and demonstrate GRAM-based tunable nanophotonic devices in the visible spectrum. Further, high-efficiency and programmable laser raster-scanning patterns can be locally controlled by adjusting power and speed, without any mask-assisted or complex nanofabrication. Our approach casts a distinct, multilevel, and reversible postfabrication recipe to modify a solid material's properties at the atomic scale, opening avenues for optical materials engineering, information storage, display, and encryption, as well as advanced thermal optics and photonics.

2.
Inorg Chem ; 2024 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-39287929

RESUMEN

Metallacyclopropanes are highly strained and very reactive organometallics; the rare-earth metal complexes bearing both highly reactive electrophilic carbon and strongly polarized metallacyclopropanes are extremely rare. This type of rare-earth metal complexes (κ2-L)RE(η2-C2B10H10)·(THF)3 [L = 1-(2-N-C5H10NCH2CH2)-3-(2,6-iPr2C6H3N═CH)-C8H4N, RE = Lu(1a), Yb(1b), Er(1c), Y(1d), Dy(1e)] bearing the indol-2-yl electrophilic carbon and carboryne-based strongly polarized metallacyclopropanes have been synthesized. Structures of complexes 1 are further confirmed by single-crystal X-ray diffraction and DFT theoretical calculations. It is found that complexes 1 have remarkable reactivity toward different polar unsaturated small molecules, elemental sulfur, and selenium to provide different products (2-15) through the selective reactions of the RE-Ccage, and RE-C2-ind bonds with the given small molecules, respectively. The reactivities of these complexes are different from those of the reported rare-earth metallacyclopropenes and d-block metal-carborynes.

3.
Free Radic Biol Med ; 223: 237-249, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39094710

RESUMEN

Chronic prostatitis-induced excessive inflammation and oxidative stress (OS) damage substantially affect men's quality of life. However, its treatment remains a major clinical challenge. Therefore, the identification of drugs that can decrease chronic prostatitis and oxidative stress targets is urgent and essential. CXCR4 is a classic chemokine receptor that is crucially associated with the occurrence and development of inflammation. This investigation aimed to elucidate how CXCR4 affects prostatitis regression and progression. The effect of CXCR4 on chronic prostatitis was evaluated by HE staining, immunohistochemistry, immunofluorescence, PCR, and TUNEL analyses. Furthermore, CXCR4 influence on metabolism was also evaluated by monitoring body weight, body temperature, food intake, and LC/MS. Additionally, chromatin immunoprecipitation, Western blot, and double luciferase reporter gene assays were carried out to elucidate the mechanism by which CXCR4 modulates Fads2 transcription by PPARγ. Lastly, ROS, DHE, mito-tracker, and ATP were utilized to validate the α-linolenic acid's protective effect against OS in prostate epithelial cells. It was revealed that the inhibition of CXCR4 can effectively alleviate prostatitis in mice. Furthermore, downregulating CXCR4 expression can markedly reduce the inflammatory cell infiltration in mouse prostates, decrease the elevated levels of DNA damage markers,MDA and 4-HNE, and mitigate apoptosis of prostatic epithelial cells. Moreover, treatment of CXCR4 knockdown mice with a PPARγ inhibitor revealed different degrees of changes in the above phenotypes. Mechanistically, the PPARγ protein translocates to the nucleus and serves as a transcription factor to regulate Fads2 expression, thereby altering PUFA metabolism. Additionally, in vitro experiments indicated that α-linolenic acid can effectively alleviate OS damage and RWPE-1 cell apoptosis by protecting mitochondrial function and enhancing the antioxidant capacity of prostatic epithelial cells. In conclusion, reducing the levels of CXCR4 can alleviate inflammation and OS damage in chronic prostatitis.


Asunto(s)
Ácido Graso Desaturasas , Estrés Oxidativo , PPAR gamma , Prostatitis , Receptores CXCR4 , Masculino , Animales , Receptores CXCR4/metabolismo , Receptores CXCR4/genética , Ratones , Prostatitis/metabolismo , Prostatitis/patología , Prostatitis/genética , Prostatitis/tratamiento farmacológico , PPAR gamma/metabolismo , PPAR gamma/genética , Ácido Graso Desaturasas/genética , Ácido Graso Desaturasas/metabolismo , Humanos , Modelos Animales de Enfermedad , Apoptosis , Ácidos Grasos Insaturados/metabolismo , Ácido alfa-Linolénico/farmacología , Ácido alfa-Linolénico/metabolismo , Próstata/patología , Próstata/metabolismo , Próstata/efectos de los fármacos , Ratones Endogámicos C57BL , Regulación de la Expresión Génica
4.
Biochim Biophys Acta Mol Basis Dis ; 1870(7): 167336, 2024 10.
Artículo en Inglés | MEDLINE | ID: mdl-38972433

RESUMEN

Epiregulin (EREG) is a member of the epidermal growth factor (EGF) family. An increasing body of evidence has demonstrated the pivotal role of EREG in the pathogenesis and progression of various malignancies. However, the clinical significance and biological role of EREG in pancreatic ductal adenocarcinoma (PDAC) have yet to be fully elucidated. We found that EREG is highly expressed in PDAC tissues compared with paracancerous tissues through public databases and clinical samples. High EREG expression predicted worse overall survival (OS) and recurrence-free survival (RFS) in patients with PDAC. Multivariate analysis revealed that EREG can serve as an independent prognostic indicator. In addition, EREG silencing inhibited PDAC cell proliferation, migration, progression, altered cell cycle, facilitated apoptosis in vitro and suppressed tumor growth in vivo. Conversely, EREG overexpression facilitated the proliferation, migration, and invasion in PaTu-8988 t cell. Through transcriptome sequencing and experimental verification, we found EREG mediates PDAC tumorigenesis through ERK/p38 MAPK signaling pathway. Moreover, we found EREG expression is closely related to PD-L1 expression in PDAC tissues and cells. Therefore, EREG is expected to be a prospective prognostic and therapeutic marker for PDAC.


Asunto(s)
Carcinoma Ductal Pancreático , Proliferación Celular , Epirregulina , Sistema de Señalización de MAP Quinasas , Neoplasias Pancreáticas , Humanos , Carcinoma Ductal Pancreático/patología , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/metabolismo , Neoplasias Pancreáticas/patología , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Masculino , Femenino , Animales , Ratones , Proliferación Celular/genética , Epirregulina/metabolismo , Epirregulina/genética , Línea Celular Tumoral , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/genética , Persona de Mediana Edad , Carcinogénesis/genética , Carcinogénesis/metabolismo , Regulación Neoplásica de la Expresión Génica , Pronóstico , Movimiento Celular/genética , Apoptosis/genética , Silenciador del Gen , Ratones Desnudos
5.
Inorg Chem ; 63(32): 14860-14875, 2024 Aug 12.
Artículo en Inglés | MEDLINE | ID: mdl-39069833

RESUMEN

The pincer rare-earth dialkyl complexes [κ3-LRE(CH2SiMe3)2 (RE = Lu(1a), Yb(1b), Er(1c), Y(1d), Dy(1e))] with the indol-2-yl-based NCN pincer ligand were synthesized by the reactions of the proligand HL (L = 1-Me2NCH2CH2-3-(2-iPrC6H5N═CH)C8H4N) with RE(CH2SiMe3)3(THF)2. These complexes exhibited a variety of reactivities toward organic compounds such as amines, triphenylphosphine ylide, N-phenylimidazole, pyridine derivatives, and o-carborane leading to σ-bond metathesis, migration insertion, and redox reaction products. The reactions of the dialkyl rare-earth metal complexes with o-carborane afforded the novel NCN pincer-ligated carboryne-based metallacyclopropanes which reacted with diphenyl ketone to give insertion products of the RE-C2-ind and one of the RE-Ccage bonds, while the reaction of the carboryne-based metallacyclopropanes with diphenyldiazomethane produced the di-aza-metallacyclopentanes via the insertions of the N═N bond of the diphenyldiazomethane into two RE-Ccage bonds and the RE-C2-ind bond. The reactions of the dialkyl complexes with 2 equiv of 2,2'-bipyridine afforded the pincer-ligated bis(2,2'-bipyridyl monoanionic radical) complexes via the homolytic redox reaction.

6.
Nat Commun ; 15(1): 6001, 2024 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-39019865

RESUMEN

A two-dimensional (2D) Weyl semimetal, akin to a spinful variant of graphene, represents a topological matter characterized by Weyl fermion-like quasiparticles in low dimensions. The spinful linear band structure in two dimensions gives rise to distinctive topological properties, accompanied by the emergence of Fermi string edge states. We report the experimental realization of a 2D Weyl semimetal, bismuthene monolayer grown on SnS(Se) substrates. Using spin and angle-resolved photoemission and scanning tunneling spectroscopies, we directly observe spin-polarized Weyl cones, Weyl nodes, and Fermi strings, providing consistent evidence of their inherent topological characteristics. Our work opens the door for the experimental study of Weyl fermions in low-dimensional materials.

7.
Small ; 20(34): e2308858, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38618927

RESUMEN

Although TiNb2O7 (TNO) with comparable operating potential and ideal theoretical capacity is considered to be the most ideal replacement for negative Li4Ti5O12 (LTO), the low ionic and electronic conductivity still limit its practical application as satisfactory anode for lithium-ion batteries (LIBs) with high-power density. Herein, TNO nanoparticles modified by Cerium (Ce) with outstanding electrochemical performance are synthesized. The successful introduction of Ce3+ in the lattice leads to increased interplanar spacing, refined grain size, more oxygen vacancy, and a smaller lithium diffusion barrier, which are conducive to improve conductivity of both Li+ and electrons. As a result, the modified TNO reaches high reversible capacity of 256.0 mA h g-1 at 100 mA g-1 after 100 cycles, and 183.0 mA h g-1 even under 3200 mA g-1. In particular, when the temperature drops to -20 °C, the cell undergoing 1500 cycles at a high current density of 500 mA g-1 can still reach 89.7 mA h g-1, corresponding to a capacity decay rate per cycle of only 0.033%. This work provides a new way to improve the electrochemical properties of alternative anodes for LIBs at extreme temperature.

8.
Transplant Rev (Orlando) ; 38(2): 100841, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38518424

RESUMEN

Rat orthotopic liver transplantation (ROLT) serves as an ideal animal model and has gained popularity in addressing complications and perioperative treatments related to clinical liver transplantation. Through extensive research on ROLT model construction, the conventional "two-cuff" method has gradually become established. However, traditional methods still present challenges including limited visual field during vascular suturing, vascular torsion, biliary tract injuries, and prolonged anhepatic periods. Consequently, this paper aims to review the latest advancements and various techniques in this field, providing a valuable reference for individuals interested in constructing ROLT models.


Asunto(s)
Trasplante de Hígado , Humanos , Ratas , Animales , Trasplante de Hígado/métodos , Modelos Animales , Anastomosis Quirúrgica
9.
Phys Rev Lett ; 132(5): 056301, 2024 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-38364160

RESUMEN

Recent experiments reported an antisymmetric planar Hall effect, where the Hall current is odd in the in plane magnetic field and scales linearly with both electric and magnetic fields applied. Existing theories rely exclusively on a spin origin, which requires spin-orbit coupling to take effect. Here, we develop a general theory for the intrinsic planar Hall effect (IPHE), highlighting a previously unknown orbital mechanism and connecting it to a band geometric quantity-the anomalous orbital polarizability (AOP). Importantly, the orbital mechanism does not request spin-orbit coupling, so sizable IPHE can occur and is dominated by an orbital contribution in systems with weak spin-orbit coupling. Combined with first-principles calculations, we demonstrate our theory with quantitative evaluation for bulk materials TaSb_{2}, NbAs_{2}, and SrAs_{3}. We further show that AOP and its associated orbital IPHE can be greatly enhanced at topological band crossings, offering a new way to probe topological materials.

10.
Small ; 20(9): e2304147, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37875665

RESUMEN

Room-temperature gallium-based liquid metals (RT-GaLMs) have garnered significant interest recently owing to their extraordinary combination of fluidity, conductivity, stretchability, self-healing performance, and biocompatibility. They are ideal materials for the manufacture of flexible electronics. By changing the composition and oxidation of RT-GaLMs, physicochemical characteristics of the liquid metal can be adjusted, especially the regulation of rheological, wetting, and adhesion properties. This review highlights the advancements in the liquid metals used in flexible electronics. Meanwhile related characteristics of RT-GaLMs and underlying principles governing their processing and applications for flexible electronics are elucidated. Finally, the diverse applications of RT-GaLMs in self-healing circuits, flexible sensors, energy harvesting devices, and epidermal electronics, are explored. Additionally, the challenges hindering the progress of RT-GaLMs are discussed, while proposing future research directions and potential applications in this emerging field. By presenting a concise and critical analysis, this paper contributes to the advancement of RT-GaLMs as an advanced material applicable for the new generation of flexible electronics.

11.
Nano Lett ; 23(23): 11266-11271, 2023 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-37976102

RESUMEN

As an ideal platform, both the theoretical prediction and first experimental verification of chiral phonons are based on transition-metal dichalcogenide materials. The manipulation of phonon chirality in these materials will have a profound effect on the study of chiral phonons. In this work, we utilize the sliding ferroelectric effect to realize the phonon chirality manipulation mechanism in transition-metal dichalcogenide materials. Based on first-principles calculations, we find the different manipulation effects of interlayer sliding on the phonon chirality and Berry curvature in bilayer and four-layer MoS2 sliding ferroelectrics. These further affect the phonon angular momentum and magnetization under a temperature gradient and the phonon Hall effect under a magnetic field. Our work connects two emerging fields and opens up a new route to manipulating phonon chirality in transition-metal dichalcogenide materials through the sliding ferroelectric mechanism.

12.
Nano Lett ; 23(16): 7358-7363, 2023 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-37535707

RESUMEN

Real Chern insulators have attracted great interest, but so far, their material realization is limited to nonmagnetic crystals and systems without spin-orbit coupling. Here, we reveal the magnetic real Chern insulator (MRCI) state in a recently synthesized metal-organic framework material Co3(HITP)2. Its ground state with in-plane ferromagnetic ordering hosts a nontrivial real Chern number, enabled by the C2zT symmetry and robustness against spin-orbit coupling. Distinct from previous nonmagnetic examples, the topological corner zero modes of MRCIs are spin-polarized. Furthermore, under small tensile strains, the material undergoes a topological phase transition from the MRCI to a magnetic double-Weyl semimetal phase, via a pseudospin-1 critical state. Similar physics can also be found in closely related materials Mn3(HITP)2 and Fe3(HITP)2, which also exist. Possible experimental detections and implications of an emerging magnetic flat band in the system are discussed.

13.
Phys Rev Lett ; 130(16): 166302, 2023 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-37154629

RESUMEN

We propose a time-reversal-even spin generation in second order of electric fields, which dominates the current induced spin polarization in a wide class of centrosymmetric nonmagnetic materials, and leads to a novel nonlinear spin-orbit torque in magnets. We reveal a quantum origin of this effect from the momentum space dipole of the anomalous spin polarizability. First-principles calculations predict sizable spin generations in several nonmagnetic hcp metals, in monolayer TiTe_{2}, and in ferromagnetic monolayer MnSe_{2}, which can be detected in experiment. Our work opens up the broad vista of nonlinear spintronics in both nonmagnetic and magnetic systems.

14.
Inorg Chem ; 62(1): 381-391, 2023 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-36576868

RESUMEN

Two different 1,3-functionalized indolyl-based proligands 1-(2-C4H7O)CH2-3-(2-tBuC6H5N═CH)C8H5N (HL1) and 1-Me2NCH2CH2-3-(2-iPrC6H5N═CH)C8H5N (HL2) were designed, prepared in high yields, and successfully applied to rare-earth metal chemistry showing different reactivities and different bondings with the central metals. The reactions of HL1 with RE(CH2SiMe3)3(THF)2 provided two types of rare-earth metal complexes: the pincer type mononuclear complexes κ3-(L1)RE(CH2SiMe3)2 [L1 = 1-(2-C4H7O)CH2-3-(2-tBuC6H5N═CH)C8H4N, RE = Lu(1), Yb(2)], and the dinuclear rare-earth metal alkyl (per alkyl/per metal) complexes having the ligand in novel coordination modes {(η1:(µ-η2:η1):η1-1-(2-C4H7O)CH2-3-[2-tBuC6H5NCH-(CH2SiMe3)]C8H4N)RECH2SiMe3}2 [RE = Er(3), Y(4), Dy(5), and Gd(6)]. Meanwhile, the reactions of HL2 with RE(CH2SiMe3)3(THF)2 led to the isolation and characterization of only the mononuclear rare-earth metal dialkyl complexes κ3-(L2)RE(CH2SiMe3)2 [L2 = 1-Me2NCH2CH2-3-(2-iPrC6H5N═CH)C8H4N, RE = Lu(7), Gd(8)] bearing the ligand in the pincer chelate form. The mononuclear complexes were formed through the sp2 C-H activation of the 2-indolyl moiety, while the dinuclear complexes were produced unexpectedly through the tandem 2-indolyl sp2 C-H activation and C═N insertion into the RE-CH2SiMe3 bond. These complexes were fully characterized by spectroscopic methods, elemental analyses, and single-crystal X-ray crystallography. The applications of the synthesized complexes as catalysts for the hydrosilylation of terminal alkenes with phenylsilane are described. Anti-Markovnikov addition products were produced by the hydrosilylation of aliphatic olefins, and Markovnikov addition products were isolated with aromatic olefins with high selectivity in the absence of cocatalysts. It is found that the dinuclear rare-earth alkyl complexes exhibited the best catalytic activity with the advantages of mild reaction conditions, short reaction time, low catalyst loading, and wide substrate applicability in comparison with the synthesized mononuclear complexes and the reported catalysts.

15.
Front Oncol ; 13: 1174999, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38162488

RESUMEN

Objective: To assess the efficacy and safety of camrelizumab plus different targeted drugs in adjuvant therapy after hepatocellular carcinoma (HCC) surgery. Patients and methods: This retrospective cohort study included HCC patients who, after undergoing failed postoperative adjuvant lenvatinib therapy, received intravenous camrelizumab 200 mg every 3 weeks (C group, n = 97), camrelizumab plus oral apatinib 250 mg daily (C+A group, n = 125), camrelizumab plus oral lenvatinib 12 mg daily (for bodyweight ≥60 kg)/lenvatinib 8 mg daily (for bodyweight <60 kg) (C+L group, n = 120), or camrelizumab plus oral sorafenib 400 mg bi-daily (C+S group, n = 114) between October 2020 and October 2021. The outcomes including the objective response rate (ORR) and disease control rate (DCR) were evaluated by RECIST 1.1 and iRECIST. The median progression-free survival (mPFS), median overall survival (mOS), 6-month OS rate, 12-month OS rate, and adverse events were evaluated. Results: As of 31 May 2022 with last follow-up time, the ORR was 17.2% for the C group, 44.6% for the C+A group, 47.9% for the C+L group, and 36.3% for the C+S group. The DCR was 72.0% for the C group, 81.8% for the C+A group, 85.5% for the C+L group, and 77.9% for the C+S group. The mPFS was 11.0 months (10.1-12.8) for the C group, 14.0 months (12.7-16.5) for the C+A group, 18.0 months (16.9-20.1) for the C+L group, and 12.0 months (9.7-14.4) for the C+S group. The mOS was 13.0 months (11.6-15.3) for the C group, 17.0 months (15.8-19.4) for the C+A group, 19.0 months (17.7-20.2) for the C+L group, and 15.0 months (14.1-17.3) for the C+S group. Grade 3 or 4 treatment-related adverse events occurred in 14 patients (14.4%) for the C group, 10 patients (8.0%) for the C+A group, 5 patients (4.2%) for the C+L group, and 11 patients (9.6%) for the C+S group. The most common adverse events were fatigue and transaminitis. Conclusion: Camrelizumab combined with lenvatinib as adjuvant therapy showed promising efficacy and manageable safety in HCC patients. It might be a potential adjuvant therapy or second-line treatment for these patients.

16.
Sci Bull (Beijing) ; 67(4): 375-380, 2022 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-36546089

RESUMEN

The past decade has witnessed a surge of interest in exploring emergent particles in condensed matter systems. Novel particles, emerged as excitations around exotic band degeneracy points, continue to be reported in real materials and artificially engineered systems, but so far, we do not have a complete picture on all possible types of particles that can be achieved. Here, via systematic symmetry analysis and modeling, we accomplish a complete list of all possible particles in time-reversal-invariant systems. This includes both spinful particles such as electron quasiparticles in solids, and spinless particles such as phonons or even excitations in electric-circuit and mechanical networks. We establish detailed correspondence between the particle, the symmetry condition, the effective model, and the topological character. This obtained encyclopedia concludes the search for novel emergent particles and provides concrete guidance to achieve them in physical systems.

17.
Biomolecules ; 12(12)2022 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-36551229

RESUMEN

Interleukin-18 (IL-18) can effectively activate natural killer (NK) cells and induce large concentrations of interferon-γ (IFN-γ). In healthy humans, IL-18 binding protein (IL-18BP) can inhibit the binding of IL-18 to IL-18R and counteract the biological action of IL-18 due to its high concentration and high affinity, thus preventing the production of IFN-γ and inhibiting NK-cell activation. Through previous studies and the phenomena observed by our group in pig-non-human primates (NHPs) liver transplantation experiments, we proposed that the imbalance in IL-18/IL-18BP expression upon transplantation encourages the activation, proliferation, and cytotoxic effects of NK cells, ultimately causing acute vascular rejection of the graft. In this research, we used Lewis-Brown Norway rat orthotopic liver transplantation (OLTx) as a model of acute vascular rejection. AAV8-Il18bp viral vectors as gene delivery vehicles were constructed for gene therapy to overexpress IL-18BP and alleviate NK-cell rejection of the graft after transplantation. The results showed that livers overexpressing IL-18BP had reduced damage and could function longer after transplantation, effectively improving the survival time of the recipients.


Asunto(s)
Vasos Sanguíneos , Terapia Genética , Rechazo de Injerto , Supervivencia de Injerto , Interleucina-18 , Trasplante de Hígado , Animales , Ratas , Rechazo de Injerto/prevención & control , Interferón gamma/genética , Interferón gamma/metabolismo , Interleucina-18/genética , Interleucina-18/metabolismo , Trasplante de Hígado/métodos , Ratas Endogámicas Lew , Supervivencia de Injerto/genética , Vasos Sanguíneos/inmunología , Vectores Genéticos
18.
Dalton Trans ; 51(46): 17795-17803, 2022 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-36349905

RESUMEN

Novel tetranuclear organocopper(I) clusters bridged by two halides and two indolyl-based NCN pincer ligands were synthesized through the reactions of Cu(I) halides with lithiated ligands. Single-crystal X-ray diffraction revealed that the structure of these complexes included a [Cu4X2]2+ cluster unit wherein the four copper ions were stabilized by multiple Cu-Cu interactions, arranged in a distorted tetrahedral fashion and the halide anions µ3-bridged with metal centers. Meanwhile, these clusters displayed excellent catalytic activities towards the hydrophosphination of alkenes under solvent-free conditions with wide functional group tolerance.

19.
Front Public Health ; 10: 1037508, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36388269

RESUMEN

Background and aim: Chronic hepatitis B (CHB) can be divided into immune tolerance (IT), immune clearance (IC), hepatitis B e antigen (HBeAg)-negative inactive/quiescent carrier (ENQ), and HBeAg-negative hepatitis (ENH) phases. The conventional biomarkers used to distinguish these phases have limitations. We examined the clinical significance of hepatitis B virus (HBV) RNA and hepatitis B core-related antigen (HBcrAg) as novel biomarkers. Methods: One hundred eighty-nine patients without treatment currently were categorized by CHB phase (IT = 46, IC = 45, ENQ = 49, ENH = 49). The associations of HBV RNA and HBcrAg with HBV DNA and alanine transaminase (ALT) were analyzed. The decision tree model was used to distinguish the four phases in the natural course of CHB. Results: The concentrations of HBV RNA and HBcrAg were highest in the IT and IC phases (P < 0.01). Serum HBV RNA was similar to HBcrAg in treatment-naïve patients. HBV RNA and HBcrAg correlated with HBV DNA in the HBeAg+ and HBeAg- status (HBV RNA: e+ r = 0.51, e- r = 0.62; HBcrAg: e+ r = 0.51, e- r = 0.71), but their association with HBV DNA differed among phases. The accuracy, sensitivity, and specificity of HBcrAg with ALT in distinguishing the CHB phases were 95.65%, 95.83%, and 95.55%, respectively. Conclusion: Serum HBV RNA and HBcrAg may be useful to monitor CHB progression.


Asunto(s)
Hepatitis B Crónica , Hepatitis B , Humanos , Antígenos e de la Hepatitis B/uso terapéutico , Hepatitis B Crónica/diagnóstico , Hepatitis B Crónica/tratamiento farmacológico , ADN Viral/uso terapéutico , Antígenos del Núcleo de la Hepatitis B/uso terapéutico , Biomarcadores , ARN/uso terapéutico
20.
Phys Chem Chem Phys ; 24(41): 25287-25297, 2022 Oct 27.
Artículo en Inglés | MEDLINE | ID: mdl-36226481

RESUMEN

Direct Z-scheme water-splitting is a promising route to enhancing the photocatalytic performance due to the effective separation of photogenerated carriers while simultaneously preserving the strong oxidation activity of holes and reduction activity of electrons. In this work, the MoSSe/XY2 (X = Hf, Zr; S, Se) heterostructures (HSs) with different contacts are proposed for Z-scheme photocatalytic water-spitting by first principles calculation. The separation of photogenerated carriers for HfSe2/SMoSe and ZrSe2/SMoSe HSs is limited by the type-I band alignment, while the hydrogen production ability of HfSe2/SeMoS and ZrSe2/SeMoS HSs is limited by the lower conduction band edge positions relative to the water reduction potential. The HfS2/SMoSe, HfS2/SeMoS, ZrS2/SMoSe, and ZrS2/SeMoS HSs are direct Z-scheme water-splitting photocatalysts with the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) occurring at the Hf(Zr)S2 layer and MoSSe layer, respectively. More excitingly, the S (or Se) vacancies effectively lower the HER overpotentials. Besides, the solar-to-hydrogen efficiencies are 6.1%, 5.9%, 6.4%, and 6.3% for HfS2/SMoSe, HfS2/SeMoS, ZrS2/SMoSe, and ZrS2/SeMoS HSs, respectively. This work paves the way for designing highly efficient overall water-splitting photocatalysts using 2D materials.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...