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1.
Artículo en Inglés | MEDLINE | ID: mdl-38940809

RESUMEN

Objective: To explore the impact of Liraglutide, a GLP-1 receptor agonist, on glycolipid metabolism and microinflammatory status in patients with abdominal obesity and type 2 diabetes. Methods: This study consecutively enrolled 60 patients with abdominal obesity and type 2 diabetes at Jiande Hospital of Traditional Chinese Medicine from October 2020 to December 2021. They were randomly divided into a control group (30 cases) receiving routine treatment and a liraglutide group (30 cases) receiving Liraglutide in addition to routine treatment for 3 months. The control group received routine treatment, which included metformin at a dose of 1g twice daily, along with dietary and exercise guidance. The liraglutide group received an initial dose of 0.6 mg daily for the first week, increased to 1.2 mg daily in the second week, and further increased to 1.8 mg daily in the third week, continuing at this dose until the end of the 12-week treatment period, with adjustments based on tolerance. Results: Significant improvements were observed in SBP, DBP, BMI, waist-to-hip ratio, and various glycolipid and microinflammatory indexes in the Liraglutide group compared to controls (P < .05). Specifically, SBP, DBP, BMI, waist-to-hip ratio, FPG, 2hPG, HbA1c, TG, TC, hs-CRP, TNF-α, and IL-6 levels decreased more significantly in the liraglutide group. Conversely, C-peptide and fasting insulin levels increased more in the liraglutide group. No significant difference in the incidence of adverse reactions was observed between the two groups (P > .05). Conclusion: Liraglutide can improve glycolipid metabolism and microinflammatory status in patients with abdominal obesity and type 2 diabetes, which has high medication safety.

2.
Molecules ; 29(3)2024 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-38338337

RESUMEN

Two types of isostructural iron-cobalt/nickel-antimony-oxo tartrate cluster-based compounds, namely (H3O)(Me2NH2)[M(H2O)6]2[FeII2SbIII12(µ4-O)3(µ3-O)8(tta)6]·6H2O (M = Co (1); Ni (3)), H5/3[Co2.5FeII4/3FeIII3(H2O)13SbV1/3FeIII2/3(µ4-O)2(µ3-O)4SbIII6(µ3-O)2(tta)6]·2H2O (2) and H2[Ni2.25FeII1.5FeIII3(H2O)14SbV0.25FeIII0.75(µ4-O)2(µ3-O)4SbIII6(µ3-O)2(tta)6]·2H2O (4) (H4tta = tartaric acid) were synthesized via simple solvothermal reactions. All the clusters in the structures adopt sandwich configurations, that is, bilayer sandwich configuration in 1 and 3 and monolayer sandwich configuration in 2 and 4. Interestingly, the monolayer sandwiched compounds 2 and 4 represent rare examples of cluster-based compounds containing mixed-valence Sb(III, V), whose center of the intermediate layer is the co-occupied [FexSbV1-x]. This is different from that of previously reported sandwich-type antimony-oxo clusters in which the center position is either occupied by a transition metal ion or a Sb(V) alone. Thus, the discovery of title compounds 2 and 4 makes the evolution of center metal ion more complete, that is, from M, MxSbV1-x to SbV. All the title compounds were fully characterized, and the photocatalysis, proton conduction and magnetism of compounds 2 and 4 were studied.

3.
Nat Mater ; 21(7): 748-753, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35710632

RESUMEN

One-dimensional electron systems exhibit fundamentally different properties than higher-dimensional systems. For example, electron-electron interactions in one-dimensional electron systems have been predicted to induce Tomonaga-Luttinger liquid behaviour. Naturally occurring grain boundaries in single-layer transition metal dichalcogenides exhibit one-dimensional conducting channels that have been proposed to host Tomonaga-Luttinger liquids, but charge density wave physics has also been suggested to explain their behaviour. Clear identification of the electronic ground state of this system has been hampered by an inability to electrostatically gate such boundaries and tune their charge carrier concentration. Here we present a scanning tunnelling microscopy and spectroscopy study of gate-tunable mirror twin boundaries in single-layer 1H-MoSe2 devices. Gating enables scanning tunnelling microscopy and spectroscopy for different mirror twin boundary electron densities, thus allowing precise characterization of electron-electron interaction effects. Visualization of the resulting mirror twin boundary electronic structure allows unambiguous identification of collective density wave excitations having two velocities, in quantitative agreement with the spin-charge separation predicted by finite-length Tomonaga-Luttinger liquid theory.

4.
Sensors (Basel) ; 23(18)2023 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-37765839

RESUMEN

This study investigates the utilization of a stepped wave frequency modulation jamming technique in radar systems. The objective is to enhance the effectiveness and robustness of false target jamming in the presence of linear frequency modulation (LFM) radars employing constant false alarm rate (CFAR) detection. The proposed method combines stepped frequency modulation with full pulse delay/sum repeat jamming to enhance resilience against uncertainties in target parameters. Theoretical analysis and simulation experiments are conducted to establish relationships between key jammer parameters, such as frequency slope and power compensation, and performance metrics, like false target distribution and CFAR masking. The results demonstrate that the proposed technique effectively maintains a dense distribution of false targets surrounding the protected target, even in the presence of uncertainties in position and signal-to-noise ratio. In comparison to existing methods, the utilization of stepped-waveform modulation enables improved control over target distribution and CFAR masking. Adaptive power allocation compensates for parameter errors, thereby enhancing robustness. Simulation results reveal that the proposed approach significantly reduces the probability of detecting the true target by over 95% under uncertain conditions, while previous methods experienced degradation. The integration of stepped waveforms optimizes false target jamming, thereby advancing electronic warfare capabilities in countering advanced radar threats. This study establishes design principles for resilient jamming architectures and supports enhanced survivability against radars employing pulse compression and CFAR detection. Moreover, the concepts proposed in this study have the potential for extension to emerging radar waveforms.

5.
Sensors (Basel) ; 23(23)2023 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-38067910

RESUMEN

To address the fuzzy reconstruction effect on distant objects in unbounded scenes and the difficulty in feature matching caused by the thin structure of power lines in images, this paper proposes a novel image-based method for the reconstruction of power transmission lines (PTLs). The dataset used in this paper comprises PTL progressive motion sequence datasets, constructed by a visual acquisition system carried by a developed Flying-walking Power Line Inspection Robot (FPLIR). This system captures close-distance and continuous images of power lines. The study introduces PL-NeRF, that is, an enhanced method based on the Neural Radiance Fields (NeRF) method for reconstructing PTLs. The highlights of PL-NeRF include (1) compressing the unbounded scene of PTLs by exploiting the spatial compression of normal L∞; (2) encoding the direction and position of the sample points through Integrated Position Encoding (IPE) and Hash Encoding (HE), respectively. Compared to existing methods, the proposed method demonstrates good performance in 3D reconstruction, with fidelity indicators of PSNR = 29, SSIM = 0.871, and LPIPS = 0.087. Experimental results highlight that the combination of PL-NeRF with progressive motion sequence images ensures the integrity and continuity of PTLs, improving the efficiency and accuracy of image-based reconstructions. In the future, this method could be widely applied for efficient and accurate 3D reconstruction and inspection of PTLs, providing a strong foundation for automated monitoring of transmission corridors and digital power engineering.

6.
Angew Chem Int Ed Engl ; 62(10): e202219025, 2023 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-36646648

RESUMEN

Intricate superstructures possess unusual structural features and promising applications. The preparation of superstructures with single-crystalline nature are conducive to understanding the structure-property relationship, however, remains an intriguing challenge. Herein we put forward a new hierarchical assembly strategy towards rational and precise construction of intricate single-crystal superstructures. Firstly, two unprecedented superclusters in Rubik's cube's form with a size of ≈2×2×2 nm3 are constructed by aggregation of eight {Pr4 Sb12 } oxohalide clusters as secondary building units (SBUs). Then, the Rubik's cubes further act as isolable tertiary building units (TBUs) to assemble diversified single-crystal superstructures. Importantly, intermediate assembly states are captured, which helps illustrate the evolution of TBU-based superstructures and thus provides a profound understanding of the assembly process of superstructures at the atomic level.

7.
Crit Rev Food Sci Nutr ; : 1-19, 2022 Dec 28.
Artículo en Inglés | MEDLINE | ID: mdl-36576258

RESUMEN

Food bioactives exhibit various health-promoting effects and are widely used in functional foods to maintain human health. After oral intake, bioactives undergo complex biological processes before reaching the target organs to exert their biological effects. However, several factors may reduce their bioavailability. Colloidal systems have attracted special attention due to their great potential to improve bioavailability and bioefficiency. Herein, we focus on the importance of in vivo studies of the biological fates of bioactives delivered by colloidal systems. Increasing evidence demonstrates that the construction, composition, and physicochemical properties of the delivery systems significantly influence the in vivo biological fates of bioactives. These results demonstrate the great potential to control the in vivo behavior of food bioactives by designing specific delivery systems. We also compare in vivo and in vitro models used for biological studies of the fate of food bioactives delivered by colloidal systems. Meanwhile, the significance of the gut microbiota, targeted delivery, and personalized nutrition should be carefully considered. This review provides new insight for further studies of food bioactives delivered by colloidal systems, as well as scientific guidance for the reasonable design of personalized nutrition.

8.
Crit Rev Food Sci Nutr ; : 1-19, 2022 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-36052655

RESUMEN

Carotenoids in plant foods are sources of pro-vitamin A and nutrients with several health benefits, including antioxidant and anticancer activities. However, humans cannot synthesize carotenoids de novo and must obtain them from the diet, typically via plant foods. We review the chemical changes of carotenoids in plant foods from farm to table and nutrition, including nutrient release and degradation during processing and metabolism in vivo. We also describe the influencing factors and proposals corresponding to enhancing the release, retention and utilization of carotenoids, thus benefiting human health. Processing methods influence the release and degradation of carotenoids, and nonthermal processing may optimize processing effects. The carotenoid profile, food matrix, and body status influence the digestion, absorption, and biotransformation of carotenoids in vivo; food design (diet and carotenoid delivery systems) can increase the bioavailability levels of carotenoids in the human body. In this review, the dynamic fate of carotenoids in plant foods is summarized systematically and deeply, focusing on changes in their chemical structure; identifying critical control points and influencing factors to facilitate carotenoid regulation; and suggesting multi-dimensional strategies based on the current state of food processing industries to achieve health benefits for consumers.

9.
Prenat Diagn ; 42(9): 1173-1181, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35818872

RESUMEN

OBJECTIVE: We verified a magnetic bead-based, simple, and fast method for circulating cell-free DNA (cfDNA) extraction from whole blood samples(CEWB) and characterised its utility in non-invasive prenatal testing (NIPT). METHOD: We extracted cfDNA from both plasma and whole blood of the patients using CEWB and compared it to that extracted using a Qiagen extraction kit; droplet digital polymerase chain reaction test was used to calculate the fragment size bias. In all, 304 samples were used for NIPT. RESULTS: The CEWB group (mean ± standard deviation [SD]: 4.34 ± 0.41 ng/ml plasma) reported less DNA weight yield than the Qiagen group (4.90 ± 0.50 ng/ml plasma). There was no significant difference between the CEWB group and the Qiagen group in the gene fragments (136 bp: p = 0.064 and 420 bp: p = 0.534). In a parallel cohort study to characterise the utility of the CEWB method in NIPT, the treatment group extracted by CEWB showed a sensitivity of 100%, a specificity of 99.65%, and a positive predictive value of 95%. CONCLUSIONS: This study demonstrated that CEWB achieves an acceptable yield of DNA without contamination from genomic DNA. Subsequent clinical experiments in a parallel cohort indicated its utility for NIPT.


Asunto(s)
Ácidos Nucleicos Libres de Células , Diagnóstico Prenatal , Ácidos Nucleicos Libres de Células/análisis , Estudios de Cohortes , ADN , Femenino , Humanos , Reacción en Cadena de la Polimerasa/métodos , Embarazo , Diagnóstico Prenatal/métodos
10.
Sensors (Basel) ; 22(8)2022 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-35458813

RESUMEN

The demodulation method of optical fiber sensors utilized in power transformer partial discharge (PD) detection is insufficient for engineering applications. We design a distributed feedback fiber laser (DFB-FL) PD detection system with an asymmetric 3 × 3 coupler and propose an ultra-high signal-to-noise ratio (SNR) demodulation scheme by eliminating the main factors that affect the traditional method using an asymmetric 3 × 3 coupler. The power transformer PD detection results reveal that the proposed scheme is free from 3 × 3 coupler asymmetry issues, with an average SNR of 38.30 dB, which is much higher than the widely used demodulation method and the piezoelectric transducer sensor. The average SNR of the system is increased by 24.2 dB with the proposed method.

11.
Anal Chem ; 93(35): 11991-12000, 2021 09 07.
Artículo en Inglés | MEDLINE | ID: mdl-34424685

RESUMEN

Cyclooxygenase-2 (COX-2) fluorescent probes are promising tools for early diagnosis of cancer. Traditionally, COX-2 probes were designed by connecting two parts, a fluorophore and a COX-2 binding unit, via a flexible linker. Herein, a new class of COX-2-specific fluorescent probes have been developed via one-step modification from rofecoxib by an integrative approach to combine the binding unit and the fluorophore into one. Among them, several new rofecoxib analogues not only exhibited still potent COX-2 binding ability but also exhibited attractive fluorescence properties, such as tunable blue-red emission, solvatochromism, aggression-induced emission behavior, and mechanochromism. Notably, the emission of 2a16 can be switched between green-yellow in the crystalline state and red-orange in the amorphous state by grinding and fuming treatments. Furthermore, the highly fluorescent compound 2a16 (Φf = 0.94 in powder) displayed a much stronger fluorescence imaging of COX-2 in HeLa cancer cells overexpressing COX-2 than RAW264.7 normal cells with a minimal expression of COX-2. Most importantly, 2a16 can light up human cancer tissues from adjacent normal tissues with a much brighter fluorescence by targeting the COX-2 enzyme. These results demonstrated the potential of 2a16 as a new red fluorescent probe for human cancer imaging in clinical applications.


Asunto(s)
Colorantes Fluorescentes , Sulfonas , Ciclooxigenasa 2 , Humanos , Lactonas
12.
Nanotechnology ; 32(22)2021 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-33321482

RESUMEN

The composite particles composed of quantum dots coated with silica and grafted with copolymer of polyethylene glycol and low molecular weight polyethylene terephthalate (QDs@SiO2-PEG-LMPET) are synthesized. The internal QDs provide luminescent performance and combine with SiO2to form QDs@SiO2with good dispersion to solve the defect that small-sized SiO2is prone to agglomerate. The block polymer LMPET-PEG grafted on the surface can make the composite particles better compatible with the PET matrix. In summary, QDs@SiO2-PEG-LMPET not only play the same role as SiO2to enhance the crystallization performance of PET matrix, but also provide stable luminescence performance, which is multifunctional additive with broad application prospects.

13.
Phytopathology ; 111(3): 500-508, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32876530

RESUMEN

G-negative bacteria produce myriad N-acyl-homoserine lactones (AHLs) that can function as quorum sensing (QS) signaling molecules. AHLs are also known to regulate various plant biological activities. p-Coumaroyl-homoserine lactone (pC-HSL) is the only QS molecule produced by a photosynthetic bacterium, Rhodopseudomonas palustris. The role of pC-HSL in the interaction between R. palustris and plant has not been investigated. In this study, we investigated the effect of pC-HSL on plant immunity and found that this QS molecule can induce a systemic resistance to Tobacco mosaic virus (TMV) infection in Nicotiana benthamiana. The results show that pC-HSL treatment can prolong the activation of two mitogen-associated protein kinase genes (i.e., NbSIPK and NbWIPK) and increase the expression of transcription factor WRKY8 as well as immune response marker genes NbPR1 and NbPR10, leading to an increased accumulation of reactive oxygen species (ROS) in the TMV-infected plants. Our results also show that pC-HSL treatment can increase activities of two ROS-scavenging enzymes, peroxidase and superoxide dismutase. Knockdown of NbSIPK or NbWIPK expression in N. benthamiana plants through virus-induced gene silencing nullified or attenuated pC-HSL-induced systemic resistance, indicating that the functioning of pC-HSL relies on the activity of those two kinases. Meanwhile, pC-HSL-pretreated plants also showed a strong induction of kinase activities of NbSIPK and NbWIPK after TMV inoculation. Taken together, our results demonstrate that pC-HSL treatment increases plant resistance to TMV infection, which is helpful to uncover the outcome of interaction between R. palustris and its host plants.


Asunto(s)
Percepción de Quorum , Virus del Mosaico del Tabaco , 4-Butirolactona/análogos & derivados , Enfermedades de las Plantas , Rhodopseudomonas , Nicotiana , Regulación hacia Arriba
14.
Entropy (Basel) ; 23(8)2021 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-34441231

RESUMEN

With the development of information technology, it has become a popular topic to share data from multiple sources without privacy disclosure problems. Privacy-preserving record linkage (PPRL) can link the data that truly matches and does not disclose personal information. In the existing studies, the techniques of PPRL have mostly been studied based on the alphabetic language, which is much different from the Chinese language environment. In this paper, Chinese characters (identification fields in record pairs) are encoded into strings composed of letters and numbers by using the SoundShape code according to their shapes and pronunciations. Then, the SoundShape codes are encrypted by Bloom filter, and the similarity of encrypted fields is calculated by Dice similarity. In this method, the false positive rate of Bloom filter and different proportions of sound code and shape code are considered. Finally, we performed the above methods on the synthetic datasets, and compared the precision, recall, F1-score and computational time with different values of false positive rate and proportion. The results showed that our method for PPRL in Chinese language environment improved the quality of the classification results and outperformed others with a relatively low additional cost of computation.

15.
Microb Pathog ; 144: 104169, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32205210

RESUMEN

Viral myocarditis (VMC) is a type of inflammation affecting myocardial cells caused by viral infection and has been an important cause of dilated cardiomyopathy (DCM) worldwide. Type B3 coxsackievirus (CVB3), a non-enveloped positive-strand RNA virus of the Enterovirus genus, is one of most common agent of viral myocarditis. Till now, effective treatments for VMC are lacking due to lack of drugs or vaccine. Lithium chloride (LiCl) is applied in the clinical management of manic depressive disorders. Accumulating evidence have demonstrated that LiCl, also as an effective antiviral drug, exhibited antiviral effects for specific viruses. However, there are few reports of evaluating LiCl's antiviral effect in mice model. Here, we investigated the inhibitory influence of LiCl on the CVB3 replication in vitro and in vivo and the development of CVB3-induced VMC. We found that LiCl significantly suppressed CVB3 replication in HeLa via inhibiting virus-induced cell apoptosis. Moreover, LiCl treatment in vivo obviously inhibited virus replication within the myocardium and alleviated CVB3-induced acute myocarditis. Collectively, our data demonstrated that LiCl inhibited CVB3 replication and negatively regulated virus-triggered inflammatory responses. Our finding further expands the antiviral targets of LiCl and provides an alternative agent for viral myocarditis.


Asunto(s)
Antivirales/farmacología , Cardiomiopatía Dilatada/tratamiento farmacológico , Infecciones por Coxsackievirus/tratamiento farmacológico , Enterovirus Humano B/efectos de los fármacos , Cloruro de Litio/farmacología , Miocarditis/tratamiento farmacológico , Animales , Apoptosis/efectos de los fármacos , Cardiomiopatía Dilatada/prevención & control , Cardiomiopatía Dilatada/virología , Línea Celular , Infecciones por Coxsackievirus/prevención & control , Infecciones por Coxsackievirus/virología , Modelos Animales de Enfermedad , Reposicionamiento de Medicamentos , Células HEK293 , Células HeLa , Humanos , Masculino , Ratones , Ratones Endogámicos BALB C , Miocarditis/prevención & control , Miocarditis/virología , Miocardio/patología , Replicación Viral/efectos de los fármacos
16.
Chemistry ; 26(7): 1624-1632, 2020 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-31971636

RESUMEN

Although supertetrahedral Tn sulfide clusters (n=2-6) have been extensively explored, the synthesis of Tn selenide clusters with n>4 has not been achieved thus far. Reported here are ionic-liquid (IL)-assisted precursor route syntheses, characterizations, and the photocatalytic properties of six new M-In-Q (M=Cu or Cd; Q=Se or Se/S) chalcogenide compounds, namely [Bmmim]12 Cu5 In30 Q52 Cl3 (Im) (Q=Se (T5-1), Se48.5 S3.5 (T5-2); Bmmim=1-butyl-2,3-dimethylimidazolium, Im=imidazole), [Bmmim]11 Cd6 In28 Q52 Cl3 (MIm) (Q=Se (T5-3), Se28.5 S23.5 (T5-4), Se16 S36 (T5-5); MIm=1-methylimidazole), and [Bmmim]9 Cd6 In28 Se8 S44 Cl(MIm)3 (T5-6). The cluster compounds T5-1 and T5-3 represent the largest molecular supertetrahedral Tn selenide clusters to date. Under visible-light illumination, the Cu-In-Q compounds showed photocatalytic activity towards the decomposition of crystal violet, whereas the Cd-In-Q compounds exhibited good photocatalytic H2 evolution activity. Interestingly, the experimental results show that the photocatalytic performances of the selenide/sulfide solid solutions were significantly better than those of their selenide analogues, for example, the degradation time of the organic dye with T5-2 was much shorter than that with T5-1, whereas the photocatalytic H2 evolution efficiencies with T5-3-T5-6 improved significantly with increasing sulfur content. This work highlights the significance of IL-assisted precursor route synthesis and the tuning of photocatalytic properties through the formation of solid solutions.

17.
Inorg Chem ; 59(4): 2337-2347, 2020 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-31999443

RESUMEN

Thiol-amine solvent mixtures have been widely applied in the solution processing of binary chalcogenide thin films due to their excellent ability to dissolve various bulk binary chalcogenides. However, application of this solvent system in preparing new crystalline chalcogenidometalates has not been explored. In this work, by using a thiol-amine solvent mixture of n-butylamine (BA) and 1,2-ethanedithiol (EDT) as the reaction medium and protonated piperazine (pip) cation as the template, we synthesized a series of new chalcogenidoarsenates with structures ranging from discrete clusters to two-dimensional layers, namely, [pipH2][pipH][AsS4] (1), [pipH2][pipH][As(Se0.4S0.6)4] (2), [pipH2]2[pipH]2[In2AsIII2AsV2S13.3(S2)0.7] (3), [pipH2]2[pipH]2[In2AsIII2AsV2S10.2Se3.1(Se2)0.7] (4), [pipH2]0.5[AsS(S2)] (5), [pipH2]0.5[AsS2] (6), [pipH]2[AgAsS4] (7), [pipH2]1.5[GaAsIIIAsVS7] (8), and Cs2[pipH]2[InAs6S12]Cl (9). Particularly, compounds 3, 4, and 8 contain mixed-valent AsIII and AsV ions in their discrete clusters and one-dimensional chain. In addition, compound 5 could thermodynamically transform to compound 6 with increasing reaction temperature, which may be attributed to the thermodynamically unstable S-S species in the chains of 5. The BA-EDT solvent mixture was crucial to the synthesis of these compounds, since no title crystals can be prepared by replacing the BA-EDT solvent mixture with other conventional solvents or removing one component of the BA-EDT solvent mixture from the reaction system. Our research demonstrates that thiol-amine solvent systems could be promising reaction media for growing novel crystalline chalcogenidometalates.

18.
Inorg Chem ; 58(8): 5126-5133, 2019 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-30946583

RESUMEN

The discrete supertetrahedral chalcogenido T n clusters can be regarded as a type of quantum dot (QD) with precise structure and uniform size. They were commonly studied in the solid state because of their poor solubility or highly negative charge that leads to instability in common solvents. These drawbacks limit their potential applications as efficient photocatalysts. Herein we first obtained a sulfide compound via an ionic-liquid-assisted precursor method, namely, (BMMim)9(Cd3In17S31Cl4) (T4-1, BMMim = 1-butyl-2,3-dimethylimidazolium). T4-1 is characteristic of the discrete anionic T4 cluster and is insoluble in common solvents. Introducing Se into the structure resulted in compounds (BMMim)9(Cd3In17S13Se18Cl4) (T4-2) and (BMMim)9(Cd3In17Se31Cl4)(4,4'-bpy) (T4-3) with narrower band gaps. Moreover, T4-2 and T4-3 were soluble in dimethyl sulfoxide (DMSO) probably because of weaker interactions between cations and anions than in T4-1. The solution stability of these clusters has been confirmed by mass spectrometry. Further characterization reveals that the highly dispersed T4 clusters exposed more active sites in solution, so their rates of relevant H2 production were improved to be ∼5 times that in the solid state. To our knowledge, this is the first time that highly dispersed T n clusters have been applied in photocatalytic H2 generation.

19.
Phys Rev Lett ; 119(4): 047001, 2017 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-29341756

RESUMEN

It is well known that non-Abelian Majorana zero modes (MZM) are located at vortex cores in a p_{x}+𝒾p_{y} topological superconductor, which can be realized in a 2D spin-orbit coupled system with a single Fermi surface and by proximity coupling to an s-wave superconductor. Here we show that the existence of non-Abelian MZMs is unrelated to the bulk topology of a 2D superconductor, and propose that such exotic modes can result in a much broader range of superconductors, being topological or trivial. For a generic 2D system with multiple Fermi surfaces that is gapped out by superconducting pairings, we show that at least a single MZM survives if there are only an odd number of Fermi surfaces of which the corresponding superconducting orders have vortices; such a MZM is protected by an emergent Chern-Simons invariant, irrespective of the bulk topology of the superconductor. This result enriches new experimental schemes for realizing non-Abelian MZMs. In particular, we propose a minimal scheme to realize the MZMs in a 2D superconducting Dirac semimetal with trivial bulk topology, which can be well achieved based on recent cold-atom experiments.

20.
Ultrasonics ; 139: 107278, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38471355

RESUMEN

This paper calculates the acoustic shadow zone of the guided wave in a variable thickness plate. The variable thickness plate has a wide range of applications in bridges, ships, etc., and the guided wave is often used for its nondestructive testing. The velocity gradient induced by thickness variations will deflect the guided wave towards lower phase velocities. Both frequency and thickness variation play crucial roles in determining the extent of path bending. In particular, the guided wave can undergo reverse propagation at the non-boundary of the plate. This curved propagation path results in an acoustic shadow zone, inaccessible to direct waves. This article calculates and experimentally verifies the curved propagation path of dispersive guided waves. Experiments show that the degree of propagation path bending increases with the increase of frequency in a certain frequency range. On the path that varies along the thickness, the experiment observes an acoustic shadow zone that accounts for nearly 25% of the total path. Additionally, a practical case study involving a guided wave with a curved path is presented. Consideration of the curved path improves the positioning accuracy, offering insights into damage location in variable thickness plates. This research on the propagation path and acoustic shadow zone contributes to advancing the understanding of guided wave propagation characteristics and enhancing their application in nondestructive testing for variable thickness structures.

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