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1.
Proc Natl Acad Sci U S A ; 120(18): e2218856120, 2023 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-37094162

RESUMEN

The anomalous metallic state (AMS) emerging from a quantum superconductor-to-metal transition is a subject of great current interest since this exotic quantum state exhibits unconventional transport properties that challenge the core physics principles of Fermi liquid theory. As the AMS concept is historically derived from disordered two-dimensional (2D) systems, related studies have predominately concentrated on 2D materials. The AMS behaviors in three-dimensional (3D) systems have been rarely reported to date, which raises intriguing questions on the fundamental nature of pertinent physics. Here, we report experimental evidence for a 3D AMS in highly compressed titanium metal that exhibits superconductivity with a critical temperature (Tc) reaching near-record 25.1 K among elemental superconductors, offering a favorable material template for exploring 3D AMS. At sufficiently strong magnetic fields, unusual transport behaviors set in over a wide pressure range, showcasing AMS hallmarks of a low-temperature saturation resistance below the Drude value and giant positive magnetoresistance. These findings reveal a 3D AMS in simple elemental systems and, more importantly, provide a fresh platform for probing the decades-long enigmatic underlying physics.

2.
PLoS Genet ; 18(7): e1010285, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35830385

RESUMEN

During evolutionary adaptation, the mechanisms for self-regulation are established between the normal growth and development of plants and environmental stress. The phytohormone jasmonate (JA) is a key tie of plant defence and development, and JASMONATE-ZIM DOMAIN (JAZ) repressor proteins are key components in JA signalling pathways. Here, we show that JAZ expression was affected by leaf senescence from the transcriptomic data. Further investigation revealed that SlJAZ10 and SlJAZ11 positively regulate leaf senescence and that SlJAZ11 can also promote plant regeneration. Moreover, we reveal that the SlJAV1-SlWRKY51 (JW) complex could suppress JA biosynthesis under normal growth conditions. Immediately after injury, SlJAZ10 and SlJAZ11 can regulate the activity of the JW complex through the effects of electrical signals and Ca2+ waves, which in turn affect JA biosynthesis, causing a difference in the regeneration phenotype between SlJAZ10-OE and SlJAZ11-OE transgenic plants. In addition, SlRbcs-3B could maintain the protein stability of SlJAZ11 to protect it from degradation. Together, SlJAZ10 and SlJAZ11 not only act as repressors of JA signalling to leaf senescence, but also regulate plant regeneration through coordinated electrical signals, Ca2+ waves, hormones and transcriptional regulation. Our study provides critical insights into the mechanisms by which SlJAZ11 can induce regeneration.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Calcio/metabolismo , Ciclopentanos/metabolismo , Regulación de la Expresión Génica de las Plantas , Oxilipinas/metabolismo , Senescencia de la Planta , Plantas Modificadas Genéticamente/metabolismo , Regeneración/genética , Transducción de Señal/genética
3.
J Am Chem Soc ; 146(6): 3890-3899, 2024 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-38294957

RESUMEN

Topological insulators offer significant potential to revolutionize diverse fields driven by nontrivial manifestations of their topological electronic band structures. However, the realization of superior integration between exotic topological states and superconductivity for practical applications remains a challenge, necessitating a profound understanding of intricate mechanisms. Here, we report experimental observations for a novel superconducting phase in the pressurized second-order topological insulator candidate Ta2Pd3Te5, and the high-pressure phase maintains its original ambient pressure lattice symmetry up to 45 GPa. Our in situ high-pressure synchrotron X-ray diffraction, electrical transport, infrared reflectance, and Raman spectroscopy measurements, in combination with rigorous theoretical calculations, provide compelling evidence for the association between the superconducting behavior and the densified phase. The electronic state change around 20 GPa was found to modify the topology of the Fermi surface directly, which synergistically fosters the emergence of robust superconductivity. In-depth comprehension of the fascinating properties exhibited by the compressed Ta2Pd3Te5 phase is achieved, highlighting the extraordinary potential of topological insulators for exploring and investigating high-performance electronic advanced devices under extreme conditions.

4.
J Gene Med ; 26(1): e3647, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38084655

RESUMEN

Breast cancer is the most commonly diagnosed cancer among women. The primary treatment options include surgery, radiotherapy, chemotherapy, targeted therapy and hormone therapy. The effectiveness of breast cancer therapy varies depending on the stage and aggressiveness of the cancer, as well as individual factors. Advances in early detection and improved treatments have significantly increased survival rates for breast cancer patients. Nevertheless, specific subtypes of breast cancer, particularly triple-negative breast cancer, still lack effective treatment strategies. Thus, novel and effective therapeutic targets for breast cancer need to be explored. As substrates of protein synthesis, amino acids are important sources of energy and nutrition, only secondly to glucose. The rich supply of amino acids enables the tumor to maintain its proliferative competence through participation in energy generation, nucleoside synthesis and maintenance of cellular redox balance. Amino acids also play an important role in immune-suppressive microenvironment formation. Thus, the biological effects of amino acids may change unexpectedly in tumor-specific or oncogene-dependent manners. In recent years, there has been significant progress in the study of amino acid metabolism, particularly in their potential application as therapeutic targets in breast cancer. In this review, we provide an update on amino acid metabolism and discuss the therapeutic implications of amino acids in breast cancer.


Asunto(s)
Aminoácidos , Neoplasias de la Mama Triple Negativas , Humanos , Femenino , Inmunoterapia , Neoplasias de la Mama Triple Negativas/metabolismo , Microambiente Tumoral
5.
Small ; 20(25): e2308724, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38229571

RESUMEN

In future information storage and processing, magnonics is one of the most promising candidates to replace traditional microelectronics. Yttrium iron garnet (YIG) films with perpendicular magnetic anisotropy (PMA) have aroused widespread interest in magnonics. Obtaining strong PMA in a thick YIG film with a small lattice mismatch (η) has been fascinating but challenging. Here, a novel strategy is proposed to reduce the required minimum strain value for producing PMA and increase the maximum thickness for maintaining PMA in YIG films by slight oxygen deficiency. Strong PMA is achieved in the YIG film with an η of only 0.4% and a film thickness up to 60 nm, representing the strongest PMA for such a small η reported so far. Combining transmission electron microscopy analyses, magnetic measurements, and a theoretical model, it is demonstrated that the enhancement of PMA physically originates from the reduction of saturation magnetization and the increase of magnetostriction coefficient induced by oxygen deficiency. The Gilbert damping values of the 60-nm-thick YIG films with PMA are on the order of 10-4. This strategy improves the flexibility for the practical applications of YIG-based magnonic devices and provides promising insights for the theoretical understanding and the experimental enhancement of PMA in garnet films.

6.
Phys Rev Lett ; 132(25): 250801, 2024 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-38996246

RESUMEN

We present a quantum sensing technique that utilizes a sequence of π pulses to cyclically drive the qubit dynamics along a geodesic path of adiabatic evolution. This approach effectively suppresses the effects of both decoherence noise and control errors while simultaneously removing unwanted resonance terms, such as higher harmonics and spurious responses commonly encountered in dynamical decoupling control. As a result, our technique offers robust, wide-band, unambiguous, and high-resolution quantum sensing capabilities for signal detection and individual addressing of quantum systems, including spins. To demonstrate its versatility, we showcase successful applications of our method in both low-frequency and high-frequency sensing scenarios. The significance of this quantum sensing technique extends to the detection of complex signals and the control of intricate quantum environments. By enhancing detection accuracy and enabling precise manipulation of quantum systems, our method holds considerable promise for a variety of practical applications.

7.
Phys Rev Lett ; 132(16): 166002, 2024 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-38701470

RESUMEN

Superconductivity has been one of the focal points in medium and high-entropy alloys (MEAs-HEAs) since the discovery of the body-centered cubic (bcc) HEA superconductor in 2014. Until now, the superconducting transition temperature (T_{c}) of most MEA and HEA superconductors has not exceeded 10 K. Here, we report a TaNbHfZr bulk MEA superconductor crystallized in the BCC structure with a T_{c} of 15.3 K which set a new record. During compression, T_{c} follows a dome-shaped curve. It reaches a broad maximum of roughly 15 K at around 70 GPa before decreasing to 9.3 K at 157.2 GPa. First-principles calculations attribute the dome-shaped curve to two competing effects, that is, the enhancement of the logarithmically averaged characteristic phonon frequency ω_{log} and the simultaneous suppression of the electron-phonon coupling constant λ. Thus, TaNbHfZr MEA may have a promising future for studying the underlying quantum physics, as well as developing new applications under extreme conditions.

8.
Inorg Chem ; 63(7): 3499-3505, 2024 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-38320745

RESUMEN

An AA'3B2B'2O12-type quadruple perovskite oxide of CaCu3Cr2Re2O12 was synthesized at 18 GPa and 1373 K. Both an A- and B-site ordered quadruple perovskite crystal structure was observed, with the space group Pn-3. The valence states are verified to be CaCu32+Cr23+Re25+O12 by bond valence sum calculations and synchrotron X-ray absorption spectroscopy. The spin interaction among Cu2+, Cr3+, and Re5+ generates a ferrimagnetic transition with the Curie temperature (TC) at about 360 K. Moreover, electric transport properties and specific heat data suggest the presence of a half-metallic feature for this compound. The present study provides a promising quadruple perovskite oxide with above-room-temperature ferrimagnetism and possible half-metallic properties, which shows potential in the usage of spintronic devices.

9.
Environ Sci Technol ; 58(28): 12719-12730, 2024 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-38959427

RESUMEN

Chlorofluorocarbons (CFCs) exert a strong greenhouse effect and constitute the largest contributor to ozone depletion. Catalytic removal is considered an effective pathway for eliminating low-concentration CFCs under mild conditions. The key issue is the easy deactivation of the catalysts due to their surface fluorination. We herein report a comparative investigation on catalytic dichlorodifluoromethane (CFC-12) removal in the absence or presence of water over the sulfuric-acid-modified three-dimensionally ordered macroporous vanadia-titania-supported Ru (S-Ru/3DOM VTO) catalysts. The S-Ru/3DOM VTO catalyst exhibited high activity (T90% = 278 °C at space velocity = 40 000 mL g-1 h-1) and good stability within 60 h of on-stream reaction in the presence of 1800 ppm of water due to the improvements in acid site amount and redox ability that promoted the adsorption of CFC-12 and the activation of C-F bonds. Compared with the case under dry conditions, catalytic performance for CFC-12 removal was better over the S-Ru/3DOM VTO catalyst in the presence of water. Water introduction mitigated surface fluorination by the replenishment of hydroxyl groups, inhibited the formation of halogenated byproducts via the surface fluorine species cleaning effect, and promoted the reaction pathway of COX2 (X = Cl/F) → carboxylic acid → CO2.


Asunto(s)
Oxidación-Reducción , Catálisis , Halogenación , Ácidos Sulfúricos/química , Titanio/química , Rutenio/química
10.
Bioorg Chem ; 150: 107604, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38981209

RESUMEN

Nineteen flavonoids were isolated from the fruits of Psoralea corylifolia L., including a novel flavanol (3) and three novel isoflavones (12-14). Their chemical structures were unequivocally determined through comprehensive spectral data analysis. The anti-proliferative effect of the isolated flavonoids was assessed in vitro using the MTT assay. Molecular docking and ELISA were employed to determine the inhibitory effects of the active compounds on ALK5. Isobavachalcone was found to inhibit TGF-ß1 induced EMT in A549 cells by Wound healing assay and Transwell chamber assay. Immunofluorescence assay and Western blot assay showed that IBC could inhibit cytoskeleton rearrangement, reduce the phosphorylation of ALK5, ERK, and Smad, down-regulate Snail expression, and up-regulate E-cadherin expression in TGF-ß1 induced A549 cells, thereby exerting the potential inhibitory effects on epithelial-mesenchymal transition (EMT) process in A549 cells. The findings presented herein establish a fundamental basis for investigating the anti-proliferative and anti-metastatic properties of psoralen flavonoids in human non-small cell lung cancer.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Proliferación Celular , Transición Epitelial-Mesenquimal , Flavonoides , Frutas , Neoplasias Pulmonares , Simulación del Acoplamiento Molecular , Psoralea , Humanos , Células A549 , Antineoplásicos Fitogénicos/farmacología , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/aislamiento & purificación , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/patología , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Transición Epitelial-Mesenquimal/efectos de los fármacos , Flavonoides/farmacología , Flavonoides/química , Flavonoides/aislamiento & purificación , Frutas/química , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/patología , Estructura Molecular , Psoralea/química , Receptor Tipo I de Factor de Crecimiento Transformador beta , Relación Estructura-Actividad , Factor de Crecimiento Transformador beta1/metabolismo , Factor de Crecimiento Transformador beta1/antagonistas & inhibidores , Isoflavonas/química , Isoflavonas/aislamiento & purificación , Isoflavonas/farmacología
11.
Cereb Cortex ; 33(7): 3840-3852, 2023 03 21.
Artículo en Inglés | MEDLINE | ID: mdl-36089839

RESUMEN

Functional abnormalities of default mode network (DMN) have been well documented in major depressive disorder (MDD). However, the association of DMN functional reorganization with antidepressant treatment and gene expression is unclear. Moreover, whether the functional interactions of DMN could predict treatment efficacy is also unknown. Here, we investigated the link of treatment response with functional alterations of DMN and gene expression with a comparably large sample including 46 individuals with MDD before and after electroconvulsive therapy (ECT) and 46 age- and sex-matched healthy controls. Static and dynamic functional connectivity (dFC) analyses showed increased intrinsic/static but decreased dynamic functional couplings of inter- and intra-subsystems and between nodes of DMN. The changes of static functional connections of DMN were spatially correlated with brain gene expression profiles. Moreover, static and dFC of the DMN before treatment as features could predict depressive symptom improvement following ECT. Taken together, these results shed light on the underlying neural and genetic basis of antidepressant effect of ECT and the intrinsic functional connectivity of DMN have the potential to serve as prognostic biomarkers to guide accurate personalized treatment.


Asunto(s)
Trastorno Depresivo Mayor , Terapia Electroconvulsiva , Humanos , Trastorno Depresivo Mayor/terapia , Trastorno Depresivo Mayor/tratamiento farmacológico , Red en Modo Predeterminado , Depresión , Imagen por Resonancia Magnética/métodos , Encéfalo/diagnóstico por imagen , Mapeo Encefálico/métodos , Antidepresivos/uso terapéutico , Vías Nerviosas/diagnóstico por imagen
12.
BMC Pulm Med ; 24(1): 287, 2024 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-38898420

RESUMEN

BACKGROUND: Early prediction of survival of hospitalized acute exacerbations of chronic obstructive pulmonary disease (AECOPD) patients is vital. We aimed to establish a nomogram to predict the survival probability of AECOPD patients. METHODS: Retrospectively collected data of 4601 patients hospitalized for AECOPD. These patients were randomly divided into a training and a validation cohort at a 6:4 ratio. In the training cohort, LASSO-Cox regression analysis and multivariate Cox regression analysis were utilized to identify prognostic factors for in-hospital survival of AECOPD patients. A model was established based on 3 variables and visualized by nomogram. The performance of the model was assesed by AUC, C-index, calibration curve, decision curve analysis in both cohorts. RESULTS: Coexisting arrhythmia, invasive mechanical ventilation (IMV) usage and lower serum albumin values were found to be significantly associated with lower survival probability of AECOPD patients, and these 3 predictors were further used to establish a prediction nomogram. The C-indexes of the nomogram were 0.816 in the training cohort and 0.814 in the validation cohort. The AUC in the training cohort was 0.825 for 7-day, 0.807 for 14-day and 0.825 for 21-day survival probability, in the validation cohort this were 0.796 for 7-day, 0.831 for 14-day and 0.841 for 21-day. The calibration of the nomogram showed a good goodness-of-fit and decision curve analysis showed the net clinical benefits achievable at different risk thresholds were excellent. CONCLUSION: We established a nomogram based on 3 variables for predicting the survival probability of AECOPD patients. The nomogram showed good performance and was clinically useful.


Asunto(s)
Nomogramas , Enfermedad Pulmonar Obstructiva Crónica , Humanos , Enfermedad Pulmonar Obstructiva Crónica/mortalidad , Masculino , Femenino , Anciano , Estudios Retrospectivos , Persona de Mediana Edad , Progresión de la Enfermedad , Pronóstico , Modelos de Riesgos Proporcionales , Mortalidad Hospitalaria , Anciano de 80 o más Años , Factores de Riesgo
13.
Environ Toxicol ; 39(1): 341-356, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37713600

RESUMEN

The Warburg effect is the preference of cancer cells to use glycolysis rather than oxidative phosphorylation to generate energy. Accumulating evidence suggests that aerobic glycolysis is widespread in hepatocellular carcinoma (HCC) and closely related to tumorigenesis. The purpose of this study was to investigate the role and mechanism of forkhead box P2 (FOXP2) in aerobic glycolysis and tumorigenesis in HCC. Here, we found that FOXP2 was lower expressed in HCC tissues and cells than in nontumor tissues and normal hepatocytes. Overexpression of FOXP2 suppressed cell proliferation and invasion of HCC cells and promoted cell apoptosis in vitro, and hindered the growth of mouse xenograft tumors in vivo. Further researches showed that FOXP2 inhibited the Warburg effect in HCC cells. Moreover, we demonstrated that FOXP2 up-regulated the expression of fructose-1, 6-diphosphatase (FBP1), and the inhibitory effect of FOXP2 on glycolysis was dependent on FBP1. Mechanistically, as a transcription factor, FOXP2 negatively regulated the transcription of lysine-specific demethylase 5A (KDM5A), and then blocked KDM5A-induced H3K4me3 demethylation in FBP1 promoter region, thereby promoting the expression of FBP1. Consistently, overexpressing KDM5A or silencing FBP1 effectively reversed the inhibitory effect of FOXP2 on HCC progression. Together, our findings revealed the mechanistic role of the FOXP2/KDM5A/FBP1 axis in glycolysis and malignant progression of HCC cells, providing a potential molecular target for the therapy of HCC.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Animales , Ratones , Carcinoma Hepatocelular/patología , Neoplasias Hepáticas/patología , Línea Celular Tumoral , Glucólisis , Transformación Celular Neoplásica/genética , Proliferación Celular/genética , Regulación Neoplásica de la Expresión Génica , Proteína 2 de Unión a Retinoblastoma/metabolismo , Factores de Transcripción Forkhead/metabolismo
14.
J Environ Sci (China) ; 138: 153-166, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38135384

RESUMEN

The PdPtVOx/CeO2-ZrO2 (PdPtVOx/CZO) catalysts were obtained by using different approaches, and their physical and chemical properties were determined by various techniques. Catalytic activities of these materials in the presence of H2O or SO2 were evaluated for the oxidation of ethylbenzene (EB). The PdPtVOx/CZO sample exhibited high catalytic activity, good hydrothermal stability, and reversible sulfur dioxide-poisoning performance, over which the specific reaction rate at 160°C, turnover frequency at 160°C (TOFPd or Pt), and apparent activation energy were 72.6 mmol/(gPt⋅sec) or 124.2 mmol/(gPd⋅sec), 14.2 sec-1 (TOFPt) or 13.1 sec-1 (TOFPd), and 58 kJ/mol, respectively. The large EB adsorption capacity, good reducibility, and strong acidity contributed to the good catalytic performance of PdPtVOx/CZO. Catalytic activity of PdPtVOx/CZO decreased when 50 ppm SO2 or (1.0 vol.% H2O + 50 ppm SO2) was added to the feedstock, but was gradually restored to its initial level after the SO2 was cut off. The good reversible sulfur dioxide-resistant performance of PdPtVOx/CZO was associated with the facts: (i) the introduction of SO2 leads to an increase in surface acidity; (ii) V can adsorb and activate SO2, thus accelerating formation of the SOx2- (x = 3 or 4) species at the V and CZO sites, weakening the adsorption of sulfur species at the PdPt active sites, and hence protecting the PdPt active sites to be not poisoned by SO2. EB oxidation over PdPtVOx/CZO might take place via the route of EB â†’ styrene â†’ phenyl methyl ketone â†’ benzaldehyde â†’ benzoic acid â†’ maleic anhydride â†’ CO2 and H2O.


Asunto(s)
Derivados del Benceno , Dióxido de Azufre , Dióxido de Azufre/química , Oxidación-Reducción , Catálisis , Estrés Oxidativo , Amoníaco/química
15.
Zhongguo Zhong Yao Za Zhi ; 49(10): 2776-2782, 2024 May.
Artículo en Zh | MEDLINE | ID: mdl-38812178

RESUMEN

This study explore the molecular mechanism of the synergistic effect of Chinese Yam polysaccharides and nucleoside analogues(NAs) on hepatitis B virus(HBV) resistance. Different concentrations of Chinese Yam polysaccharide and entecavir were ad-ded to HepG2.2.15 cells. After the cytotoxicity was detected by cell counting kit-8(CCK-8), the optimal concentration and time of the two drugs to inhibit HepG2.2.15 cells were screened out. They were divided into control group, Chinese Yam polysaccharide group, entecavir group and combination drug group(Chinese Yam polysaccharide + entecavir). The drugs were added to HepG2.2.15 cells, ELISA was used to detect the effects of each group of drugs on the secretion of hepatitis B virus surface antigen(HBsAg) and hepatitis B virus e antigen(HBeAg) in cell supernatant, probe quantitative real-time PCR(probe qRT-PCR) was used to detect the effects of drugs on HBV-DNA in HepG2.2.15 cells, and Western blot was used to detect the effects of each group of drugs on the expression of p38 MAPK, p-p38 MAPK, NTCP proteins in HepG2.2.15 cells. The qRT-PCR was used to detect the effect of drugs on the expression of p38 MAPK and NTCP mRNA in HepG2.2.15 cells. The results showed that compared with control group, the concentrations of HBeAg and HBsAg in Chinese Yam polysaccharide group, entecavir group and combination group decreased(P<0.01 or P<0.001), and both of them inhibited HBV-DNA in HepG2.2.15 cells(P<0.01), and the HBV-DNA inhibition of HepG2.2.15 cells in the combination group was more obvious(P<0.001), and the protein expression levels of p-p38 MAPK and NTCP were significantly decreased(P<0.05 or P<0.01), the mRNA expression level of p38 MAPK increased, and the mRNA expression level of NTCP decreased(P<0.05 or P<0.01). To sum up, Chinese Yam polysaccharide can reduce the expression of NTCP protein and mRNA through p38 MAPK signaling pathway and cooperate with entecavir in anti-HBV.


Asunto(s)
Antivirales , Dioscorea , Virus de la Hepatitis B , Polisacáridos , Proteínas Quinasas p38 Activadas por Mitógenos , Humanos , Virus de la Hepatitis B/efectos de los fármacos , Virus de la Hepatitis B/genética , Polisacáridos/farmacología , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/genética , Células Hep G2 , Antivirales/farmacología , Dioscorea/química , Sinergismo Farmacológico , Nucleósidos/farmacología , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Antígenos de Superficie de la Hepatitis B/metabolismo , Antígenos de Superficie de la Hepatitis B/genética , Antígenos e de la Hepatitis B/metabolismo , Hepatitis B/tratamiento farmacológico , Hepatitis B/virología , Medicamentos Herbarios Chinos/farmacología , Medicamentos Herbarios Chinos/química , Guanina/análogos & derivados , Guanina/farmacología
16.
J Am Chem Soc ; 145(2): 1301-1309, 2023 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-36579888

RESUMEN

Various transition-metal trichalcogenides (TMTC) show unique electronic properties, such as metal-insulator transition, topological insulator, and even superconducting transition. Currently, almost all metallic TMTC compounds can show superconductivity either at ambient pressure or at high pressure. However, most TMTC compounds are semiconductors and even insulators. Does superconductivity exist in any non-metallic TMTC compound by artificial manipulation? In this work, the electronic behavior of highly insulating HfS3 has been manipulated in terms of pressure. HfS3 undergoes an insulator-to-semiconductor transition near 17 GPa with a band gap reduction of ∼1 eV. Optical absorption, Raman spectroscopy, and X-ray diffraction measurements provide consistent results, suggesting the structural origin of the electronic transition. Upon further compression, HfS3 becomes a superconductor without further structural transition. The superconducting transition occurs as early as 50.6 GPa, and the Tc reaches 8.1 K at 121 GPa, which sets a new record for TMTCs. This work reveals that all TMTCs may be superconductors and opens a new avenue to explore the abundant emergent phenomena in the TMTC material family.

17.
J Am Chem Soc ; 145(29): 15869-15878, 2023 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-37449950

RESUMEN

Designing new synthesis routes to fabricate highly thermally durable precious metal single-atom catalysts (SACs) is challenging in industrial applications. Herein, a general strategy is presented that starts from dual-metal nanocrystals (NCs), using bimetallic NCs as a facilitator to spontaneously convert a series of noble metals to single atoms on aluminum oxide. The metal single atoms are captured by cation defects in situ formed on the surface of the inverse spinel (AB2O4) structure, which process provides numerous anchoring sites, thus facilitating generation of the isolated metal atoms that contributes to the extraordinary thermodynamic stability. The Pd1/AlCo2O4-Al2O3 shows not only improved low-temperature activity but also unprecedented (hydro)thermal stability for CO and propane oxidation under harsh aging conditions. Furthermore, our strategy exhibits a small scaling-up effect by the simple physical mixing of commercial metal oxide aggregates with Al2O3. The good regeneration between oxidative and reductive atmospheres of these ionic palladium species makes this catalyst system of potential interest for emissions control.

18.
J Virol ; 96(13): e0038322, 2022 07 13.
Artículo en Inglés | MEDLINE | ID: mdl-35699445

RESUMEN

Despite the rapid deployment of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines, the emergence of SARS-CoV-2 variants and reports of their immune evasion characteristics have led to an urgent need for novel vaccines that confer potent cross-protective immunity. In this study, we constructed three different SARS-CoV-2 spike S1-conjugated nanoparticle vaccine candidates that exhibited high structural homogeneity and stability. Notably, these vaccines elicited up to 50-times-higher neutralizing antibody titers than the S1 monomer in mice. Crucially, it was found that the S1-conjugated nanoparticle vaccine could elicit comparable levels of neutralizing antibodies against wild-type or emerging variant SARS-CoV-2, with cross-reactivity to SARS-CoV and Middle East respiratory syndrome coronavirus (MERS-CoV), the effect of which could be further enhanced using our designed nanoparticles. Our results indicate that the S1-conjugated nanoparticles are promising vaccine candidates with the potential to elicit potent and cross-reactive immunity against not only wild-type SARS-CoV-2, but also its variants of concern, variants of interest, and even other pathogenic betacoronaviruses. IMPORTANCE The emergence of SARS-CoV-2 variants led to an urgent demand for a broadly effective vaccine against the threat of variant infection. The spike protein S1-based nanoparticle designed in our study could elicit a comprehensive humoral response toward different SARS-CoV-2 variants of concern and variants of interest and will be helpful to combat COVID-19 globally.


Asunto(s)
Formación de Anticuerpos , Vacunas contra la COVID-19 , COVID-19 , Nanopartículas , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , Animales , Anticuerpos Neutralizantes/sangre , Anticuerpos Antivirales/sangre , Formación de Anticuerpos/inmunología , COVID-19/prevención & control , Vacunas contra la COVID-19/inmunología , Humanos , Ratones , SARS-CoV-2/genética , SARS-CoV-2/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología
19.
Chemistry ; 29(23): e202203782, 2023 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-36727499

RESUMEN

A helicene-containing arene and its linear analogue have been successfully synthesized and characterized, where the single-crystal X-ray diffraction analysis indicates that the former can arrange in an offset packing style with a π-π overlap. The introduction of pentagon-rings into the parent skeletons in the resulting compounds can boost the stability, and such helicene-containing molecule possesses higher solubility in organic solvent than the linear analogue. The structural difference has significantly influenced the optical limiting performance. The former in solution and in doped gel glass presents higher optical limiting response towards 532 nm laser than the latter. This study can enrich the functionalization of helicene, which can possess a positive effect in terms of nonlinear optical property.

20.
Diabet Med ; 40(9): e15129, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37143390

RESUMEN

AIMS: Impaired awareness of hypoglycaemia (IAH) is a complication of glucose-lowering therapies for diabetes. The purpose of this review was to estimate the pooled prevalence of IAH and unawareness of hypoglycaemia (UAH). METHODS: We searched the major databases from inception to 8 August 2022 and included all cross-sectional and cohort studies reporting IAH prevalence in people with diabetes. A random-effects model was used to pool effect values. Subgroup analysis and meta-regression were used to identify study-level characteristics affecting prevalence. RESULTS: Sixty-two studies from 21 countries published between 2000 and 2022 were included, with 39,180 participants (type 1 diabetes: 19,304 vs. Type 2 diabetes: 14,650). The pooled prevalence was 23.2% (95% CI: 18.4%-29.3%) via the Clarke questionnaire, 26.2% (95% CI: 22.9%-29.9%) via the Gold score, and 58.5% (95% CI: 53.0%-64.6%) via the Pedersen-Bjergaard method, all from studies classified as presenting a moderate and low risk of bias. The prevalence of IAH was generally higher in people with type 1 diabetes than in those with type 2 diabetes and lowest in Europe. Meta-regression results show that the duration of diabetes was a factor influencing the prevalence of IAH. The prevalence of UAH by the Pedersen-Bjergaard method was 17.6 (95% CI: 14.9%-20.3%). CONCLUSIONS: IAH is a prevalent risk event among people with type 1 and type 2 diabetes, showing clinical heterogeneity and regional variability. UAH, an adverse progression of IAH, is also a serious burden. More primary research on the prevalence of IAH is needed in areas with a high diabetes burden.


Asunto(s)
Diabetes Mellitus Tipo 1 , Diabetes Mellitus Tipo 2 , Hipoglucemia , Humanos , Diabetes Mellitus Tipo 1/complicaciones , Diabetes Mellitus Tipo 1/epidemiología , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/epidemiología , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Prevalencia , Estudios Transversales , Concienciación , Hipoglucemia/epidemiología
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