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1.
Nano Lett ; 24(4): 1268-1276, 2024 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-38241736

RESUMEN

While quasi-two-dimensional (quasi-2D) perovskites have good properties of cascade energy transfer, high exciton binding energy, and high quantum efficiency, which will benefit high-efficiency blue PeLEDs, inefficient domain distribution management and unbalanced carrier transport impede device performance improvement. Herein, (2-(9H-carbazol-9-yl)ethyl)phosphonic acid (2PACz) and methyl 2-aminopyridine-4-carboxylate (MAC) were simultaneously introduced to a blue quasi-2D perovskite film. Relying on the synergistic effect of 2PACz and MAC, it not only modulates the phase distribution inhibiting the n = 2 phase but also greatly improves the electrical property of the quasi-2D perovskite film. As a result, the as-modified blue quasi-2D PeLED demonstrated an external quantum efficiency (EQE) of 17.08% and a luminance of 10142 cd m-2. This study exemplifies the synergistic effect among dual additives and offers a new effective additive strategy modulating phase distribution and building balanced carrier transport, which paves the way for the fabrication of highly efficient blue PeLEDs.

2.
Nano Lett ; 23(23): 11082-11090, 2023 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-37991828

RESUMEN

Quasi-2D perovskites, multiquantum well materials with the energy cascade structure, exhibit impressive optoelectronic properties and a wide range of applications in various optoelectronic devices. However, the insufficient exciton energy transfer caused by the excess of small-n phases that induce nonradiative recombination and the spatially random phase distribution that impedes charge transport severely inhibit the device performance of light-emitting diodes (LEDs). Here, a faster energy transfer process and efficient carrier recombination are achieved by introducing the multifunctional additive 2-(methylsulfonyl)-4-(trifluoromethyl)benzoic acid (MTA) to manipulate the crystallization process of perovskites. The introduction of MTA not only constrains the PEA and restrains the formation of small-n phases to improve the energy transfer process but also optimizes the crystal orientation to promote charge transport. As a result, highly efficient pure green quasi-2D perovskite LEDs with a peak EQE of 25.9%, a peak current efficiency of 108.1 cd A-1, and a maximum luminance of 288798 cd m-2 are achieved.

3.
Nano Lett ; 23(4): 1582-1590, 2023 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-36763855

RESUMEN

Properties of the underlying hole transport layer (HTL) play a crucial role in determining the optoelectronic performance of perovskite light-emitting devices (PeLEDs). However, endowing the current HTL system with a deep highest occupied molecular orbital (HOMO) level concurrent with high hole mobility is still a big challenge, in particular being an open constraint toward high-efficiency blue PeLEDs. In this regard, employing the poly(9-vinylcarbazole) as a model, we perform efficient incorporation of the atomic-precision metal nanoclusters (NCs), [Ag6PL6, PL = (S)-4-phenylthiazolidine-2-thione], to achieve significant tailoring in both HOMO energy level and hole mobility. As a result, the as-modified PeLEDs exhibit an external quantum efficiency (EQE) of 14.29% at 488 nm. The presented study exemplifies the success of metal NC involved HTL engineering and offers a simple yet effective additive strategy to settle the blue PeLED HTL dilemma, which paves the way for the fabrication of highly efficient blue PeLEDs.

4.
Nano Lett ; 23(1): 82-90, 2023 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-36542057

RESUMEN

Cesium lead halide perovskite nanocrystals (PNCs) exhibit promising prospects for application in optoelectronic devices. However, electroactivated near-infrared (NIR) PNC light-emitting diodes (LEDs) with emission peaks over 800 nm have not been achieved. Herein, we demonstrate the electroactivated NIR PNC LEDs based on Yb3+-doped CsPb(Cl1-xBrx)3 PNCs with extraordinary high NIR photoluminescence quantum yields over 170%. The fabricated NIR LEDs possess an irradiance of 584.7 µW cm-2, an EQE of 1.2%, and a turn-on voltage of 3.1 V. The ultrafast quantum cutting process from the PNC host to Yb3+ has been revealed as the main mechanism of electroluminescence (EL)-activated Yb3+ for the first time via exploring how the trend between the EL intensity of PNC and Yb3+ varies with different voltages along with the tendency of temperature- and doping-concentration-dependent PL and EL spectra. This work will extend the application of PNCs to optical communication, night-vision devices, and biomedical imaging.

5.
Pak J Med Sci ; 40(6): 1099-1104, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38952520

RESUMEN

Objective: To explore the clinical effect of ranibizumab combined with laser photocoagulation (LP) in treating diabetic macular edema (DME). Methods: We retrospectively reviewed the clinical data of 118 patients with DME admitted to The Affiliated Eye Hospital of Nanchang University from May 2021 to March 2023. Among them, 38 patients received LP alone (Laser-group), 39 patients received ranibizumab alone (Ranibizumab-group), and 41 patients received LP combined with ranibizumab (Combined-group). The improvement of macular edema (ME), visual acuity, and complications between the groups were compared. Results: The time of ME regression, exudation absorption and fundus hemorrhage absorption in the Combined-group was shorter than in the Laser-group and the Ranibizumab-group (P<0.05). After treatment, the CMT and RNV of the three groups decreased compared to pretreatment levels and were lower in the Combined-group compared to the Laser-group and the Ranibizumab-group (P<0.05). BCVA increased after the treatment in all groups, and was markedly higher in the Combined-group than in the Laser and the Ranibizumab-groups (P<0.05). NO were higher in the Combined-group compared to the Laser-group and the Ranibizumab-group. The post-treatment VEGF levels decreased in all groups, and were significantly lower in the Combined-group compared to the Laser-group and the Ranibizumab-group (P<0.05). The incidence of complications in the Combined-group was lower than in the Laser-group and the Ranibizumab-group (P<0.05). Conclusions: Compared to ranibizumab or LP alone, ranibizumab combined with LP is more effective in reducing ME in patients with DEM, and is associated with fewer complications.

6.
Mol Med ; 29(1): 162, 2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-38041015

RESUMEN

BACKGROUND: The linear long non-coding RNA P14AS has previously been reported to be dysregulated in colon cancer, but the mechanistic role that P14AS plays in colon cancer progression has yet to be clarified. Accordingly, this study was developed to explore the regulatory functions of ANRIL linear transcript-P14AS in cancer. METHODS: The expression of P14AS, ANRIL, miR-23a-5p and their target genes were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot. Cell supernatants of IL6 and IL8 were measured by Enzyme linked immunosorbent (ELISA) assay. Dual-luciferase reporter assays, RNA immunoprecipitation, or pull-down assays were used to confirm the target association between miR-23a-5p and P14AS or UBE2D3. Cell proliferation and chemosensitivity of NF-κB inhibitor BAY 11-7085 were evaluated by cell counting kit 8 (CCK8). RESULTS: When P14AS was overexpressed in colon cancer cell lines, enhanced TNF-NF-κB signaling pathway activity was observed together with increases in IL6 and IL8 expression. The Pita, miRanda, and RNA hybrid databases revealed the ability of miR-23a-5p to interact with P14AS, while UBE2D3 was further identified as a miR-23a-5p target gene. The results of dual-luciferase reporter, RNA pull-down, and RNA immunoprecipitation experiments confirmed these direct interactions among P14AS/miR-23a-5p/UBE2D3. The degradation of IκBa mediated by UBE2D3 may contribute to enhanced NF-κB signaling in these cells. Moreover, the beneficial impact of P14AS on colon cancer cell growth was eliminated when cells were treated with miR-23a-5p inhibitors or UBE2D3 was silenced. As such, these findings strongly supported a role for the UBE2D3/IκBa/NF-κB signaling axis as a mediator of the ability of P14AS to promote colon cancer progression. CONCLUSIONS: These data suggested a mechanism through which the linear ANRIL transcript P14AS can promote inflammation and colon cancer progression through the sequestration of miR-23a-5p and the modulation of NF-κB signaling activity, thus highlighting P14AS as a promising target for therapeutic intervention efforts.


Asunto(s)
Neoplasias del Colon , MicroARNs , Humanos , Proliferación Celular , Neoplasias del Colon/genética , Interleucina-6/genética , Interleucina-8/genética , Luciferasas/metabolismo , MicroARNs/genética , MicroARNs/metabolismo , Procesos Neoplásicos , FN-kappa B/metabolismo , Transducción de Señal
7.
Small ; 19(42): e2302337, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37344988

RESUMEN

Perovskite solar cells (PSCs) based on 2D/3D composite structure have shown enormous potential to combine high efficiency of 3D perovskite with high stability of 2D perovskite. However, there are still substantial non-radiative losses produced from trap states at grain boundaries or on the surface of conventional 2D/3D composite structure perovskite film, which limits device performance and stability. In this work, a multifunctional magnetic field-assisted interfacial embedding strategy is developed to construct 2D/3D composite structure. The composite structure not only improves crystallinity and passivates defects of perovskite layer, but also can efficiently promote vertical hole transport and provide lateral barrier effect. Meanwhile, the composite structure also forms a good surface and internal encapsulation of 3D perovskite to inhibit water diffusion. As a result, the multifunctional effect effectively improves open-circuit voltage and fill factor, reaching maximum values of 1.246 V and 81.36%, respectively, and finally achieves power conversion efficiency (PCE) of 24.21%. The unencapsulated devices also demonstrate highly improved long-term stability and humidity stability. Furthermore, an augmented performance of 21.23% is achieved, which is the highest PCE of flexible device based on 2D/3D composite perovskite films coupled with the best mechanical stability due to the 2D/3D alternating structure.

8.
Opt Express ; 31(8): 13028-13039, 2023 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-37157449

RESUMEN

A driver safety assisting system is essential to reduce the probability of traffic accidents. But most of the existing driver safety assisting systems are simple reminders that cannot improve the driver's driving status. This paper proposes a driver safety assisting system to reduce the driver's fatigue degree by the light with different wavelengths that affect people's moods. The system consists of a camera, an image processing chip, an algorithm processing chip, and an adjustment module based on quantum dot LEDs (QLEDs). Through this intelligent atmosphere lamp system, the experimental results show that blue light reduced the driver's fatigue degree when just turned on; but as time went on, the driver's fatigue degree rebounded rapidly. Meanwhile, red light prolonged the driver's awake time. Different from blue light alone, this effect can remain stable for a long time. Based on these observations, an algorith was designed to quantify the degree of fatigue and detect its rising trend. In the early stage, the red light is used to prolong the awake time and the blue light to suppress when the fatigue value increases, so as to maximize the awake driving time. The result showed that our device prolonged the awake driving time of the drivers by 1.95 times and reduced fatigue during driving: the quantitative value of fatigue degree generally decreased by about 0.2 times. In most experiments, the subjects were able to complete four hours of safe driving, which reached the maximum length of continuous driving at night allowed by China laws. In conclusion, our system changes the assisting system from a reminder to a helper, thus effectively reducing the driving risk.

9.
Nano Lett ; 22(5): 1963-1970, 2022 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-35166553

RESUMEN

Electrocatalytic reduction of CO2 to multicarbon products is a potential strategy to solve the energy crisis while achieving carbon neutrality. To improve the efficiency of multicarbon products in Cu-based catalysts, optimizing the *CO adsorption and reducing the energy barrier for carbon-carbon (C-C) coupling are essential features. In this work, a strong local electric field is obtained by regulating the arrangement of Cu nanoneedle arrays (CuNNAs). CO2 reduction performance tests indicate that an ordered nanoneedle array reaches a 59% Faraday efficiency for multicarbon products (FEC2) at -1.2 V (vs RHE), compared to a FEC2 of 20% for a disordered nanoneedle array (CuNNs). As such, the very high and local electric fields achieved by an ordered Cu nanoneedle array leads to the accumulation of K+ ions, which benefit both *CO adsorption and C-C coupling. Our results contribute to the design of highly efficient catalysts for multicarbon products.

10.
Angew Chem Int Ed Engl ; 62(14): e202217832, 2023 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-36760216

RESUMEN

Wide-coverage near infrared (NIR) phosphor-converted LEDs possess promising potential for practical applications, but little is developed towards the efficient and wide-coverage NIR phosphors. Here, we report the single-component lanthanide (Ln3+ ) ions doped Cs2 M(In0.95 Sb0.05 )Cl6 (M=alkali metal) nanocrystals (NCs), exhibiting emission from 850 to 1650 nm with high photoluminescence quantum yield of 20.3 %, which is accomplished by shaping the multiple metal halide octahedra of double perovskite via the simple alkali metal substitution. From Judd-Ofelt theoretical calculation and spectroscopic investigations, the shaping of metal halide octahedra in Cs2 M(In1-x Sbx )Cl6 NCs can break the forbidden of f-f transition of Ln3+ , thus increasing their radiative transition rates and simultaneously boosting the energy transfer efficiency from host to Ln3+ . Finally, the wide-coverage NIR LEDs based on Sm3+ , Nd3+ , Er3+ -tridoped Cs2 K0.5 Rb0.5 (In0.95 Sb0.05 )Cl6 NCs are fabricated and employed in the multiplex gas sensing and night-vision application.

11.
J Am Chem Soc ; 144(7): 3039-3049, 2022 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-35112839

RESUMEN

Electrochemical CO2 reduction is a promising way to mitigate CO2 emissions and close the anthropogenic carbon cycle. Among products from CO2RR, multicarbon chemicals, such as ethylene and ethanol with high energy density, are more valuable. However, the selectivity and reaction rate of C2 production are unsatisfactory due to the sluggish thermodynamics and kinetics of C-C coupling. The electric field and thermal field have been studied and utilized to promote catalytic reactions, as they can regulate the thermodynamic and kinetic barriers of reactions. Either raising the potential or heating the electrolyte can enhance C-C coupling, but these come at the cost of increasing side reactions, such as the hydrogen evolution reaction. Here, we present a generic strategy to enhance the local electric field and temperature simultaneously and dramatically improve the electric-thermal synergy desired in electrocatalysis. A conformal coating of ∼5 nm of polytetrafluoroethylene significantly improves the catalytic ability of copper nanoneedles (∼7-fold electric field and ∼40 K temperature enhancement at the tips compared with bare copper nanoneedles experimentally), resulting in an improved C2 Faradaic efficiency of over 86% at a partial current density of more than 250 mA cm-2 and a record-high C2 turnover frequency of 11.5 ± 0.3 s-1 Cu site-1. Combined with its low cost and scalability, the electric-thermal strategy for a state-of-the-art catalyst not only offers new insight into improving activity and selectivity of value-added C2 products as we demonstrated but also inspires advances in efficiency and/or selectivity of other valuable electro-/photocatalysis such as hydrogen evolution, nitrogen reduction, and hydrogen peroxide electrosynthesis.

12.
Small ; 18(1): e2105415, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34787363

RESUMEN

Carbon dot (CD) based long-lived afterglow emission materials have attracted attention in recent years, but demonstration of white-light room-temperature afterglow remains challenging, due to the difficulty of simultaneous generation of multiple long-lived excited states with distinct chromatic emission. In this work, a white-light room-temperature long-lived afterglow emission from a CD powder with a high efficiency of 5.8% and Commission International de l'Eclairage (CIE) coordinates of (0.396, 0.409) is realized. The afterglow of the CDs originates from a synergy between the phosphorescence of the carbon core and the delayed fluorescence associated with the surface CN moieties, which is accomplished by matching the singlet state of the surface groups of the CDs with the long-lived triplet state of the carbon core, resulting in an efficient energy transfer. It is demonstrated how the long-lived afterglow emission of CDs can be utilized for fabrication of white light emitting devices and in anticounterfeiting applications.


Asunto(s)
Carbono , Luz , Transferencia de Energía , Fluorescencia , Temperatura
13.
Opt Express ; 30(11): 19716-19730, 2022 May 23.
Artículo en Inglés | MEDLINE | ID: mdl-36221740

RESUMEN

Metasurfaces have provided unprecedented degrees of freedom in manipulating electromagnetic (EM) waves and also granted high possibility of integrating multiple functions into one single meta-device. In this paper, we propose to incorporate the retroreflection function with transmission function by means of metasurface design and then demonstrate a dual-polarization multi-angle retroreflective metasurface (DMRM) with bilateral transmission bands. To achieve high-efficiency retroreflections, the compact bend structures (CBSs), which exhibit high reflections around 10.0 GHz in X band, are added onto the substrate of the DMRM. Two selected metasurface elements are periodically arranged so as to form 0-π-0 phase profile. By delicately adjusting the periodicity, high-efficiency retroreflections can be produced for both TE and TM-polarized waves under both vertical incidence and oblique incident angles ±50.0°, with an average efficiency of 90.2% at the designed frequency. Meanwhile, the two metasurface elements exhibit high transmission properties and minor phase disparities in S, C and Ku bands, resulting in bilateral transmission windows. Prototypes were designed and fabricated. Both simulated and measured results verified our design. This work provides an effective means of integrating retroreflection functions with other functions and may find applications in target tracking, radomes and other sensor integrated devices in higher frequency or even optical frequency bands.

14.
Front Zool ; 19(1): 25, 2022 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-36307847

RESUMEN

BACKGROUND: Predicting invasiveness requires an understanding of the propensity of a given species to thrive in areas with novel ecological challenges. Evaluation of realized niche shift of an invasive species in its invasive range, detecting the main drivers of the realized niche shift, and predicting the potential distribution of the species can provide important information for the management of populations of invasive species and the conservation of biodiversity. The Australian redback spider, Latrodectus hasselti, is a widow spider that is native to Australia and established in Japan, New Zealand, and Southeast Asia. We used ecological niche models and ordinal comparisons in an integrative method to compare the realized niches of native and invasive populations of this spider species. We also assessed the impact of several climatic predictor variables and human activity on this niche shift. We hypothesized that human impact is important for successful establishment of this anthropophilic species, and that climatic predictor variables may determine suitable habitat and thus predict invasive ranges. RESULTS: Our models showed that L. hasselti distributions are positively influenced by human impact in both of the native and invasive ranges. Maximum temperature was the most important climatic variable in predictions of the distribution of native populations, while precipitation seasonality was the most important in predictions of invasive populations. The realized niche of L. hasselti in its invasive range differed from that in its native range, indicating possible realized niche shift. CONCLUSIONS: We infer that a preference for human-disturbed environments may underlie invasion and establishment in this spider species, as anthropogenic habitat modifications could provide shelters from unsuitable climatic conditions and extreme climatic stresses to the spiders. Because Australia and the countries in which the species is invasive have differing climates, differences in the availability of certain climatic conditions could have played a role in the realized niche shift of L. hasselti.

15.
J Med Internet Res ; 24(1): e27178, 2022 01 11.
Artículo en Inglés | MEDLINE | ID: mdl-35014957

RESUMEN

BACKGROUND: Massive, easily accessible online health information empowers users to cope with health problems better. Most patients search for relevant online health information before seeing a doctor to alleviate information asymmetry. However, the mechanism of how online health information affects health empowerment is still unclear. OBJECTIVE: To study how online health information processing affects health empowerment. METHODS: We conducted a cross-sectional questionnaire study that included 343 samples from participants who had searched online health information before the consultation. Respondents' perceptions of online information cues, benefits, health literacy, and health empowerment were assessed. RESULTS: Perceived argument quality and perceived source credibility have significant and positive effects on perceived information benefits, but only perceived argument quality has a significant effect on perceived decision-making benefits. Two types of perceived benefits, in turn, affect health empowerment. The effects of perceived argument quality on perceived informational benefits and perceived decision-making benefits on health empowerment are significantly stronger for the high health literacy group than the low health literacy group (t269=7.156, P<.001; t269=23.240, P<.001). While, the effects of perceived source credibility on perceived informational benefits and perceived informational benefits on health empowerment are significantly weaker for the high health literacy group than the low health literacy group (t269=-10.497, P<.001; t269=-6.344, P<.001). The effect of perceived argument quality on perceived informational benefits shows no significant difference between high and low health literacy groups. CONCLUSIONS: In the context of online health information, perceived information benefits and perceived decision-making benefits are the antecedents of health empowerment, which in turn will be affected by perceived argument quality and perceived source credibility. Health literacy plays a moderating role in the relationship of some variables. To maximize health empowerment, online health information providers should strengthen information quality and provide differentiated information services based on users' health literacy.


Asunto(s)
Alfabetización en Salud , Estudios Transversales , Humanos , Internet , Encuestas y Cuestionarios
16.
Angew Chem Int Ed Engl ; 61(4): e202113664, 2022 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-34822728

RESUMEN

Ruthenium (Ru)-based catalysts, with considerable performance and desirable cost, are becoming highly interesting candidates to replace platinum (Pt) in the alkaline hydrogen evolution reaction (HER). The hydrogen binding at Ru sites (Ru-H) is an important factor limiting the HER activity. Herein, density functional theory (DFT) simulations show that the essence of Ru-H binding energy is the strong interaction between the 4 d z 2 orbital of Ru and the 1s orbital of H. The charge transfer between Ru sites and substrates (Co and Ni) causes the appropriate downward shift of the 4 d z 2 -band center of Ru, which results in a Gibbs free energy of 0.022 eV for H* in the RuCo system, much lower than the 0.133 eV in the pure Ru system. This theoretical prediction has been experimentally confirmed using RuCo alloy-nanosheets (RuCo ANSs). They were prepared via a fast co-precipitation method followed with a mild electrochemical reduction. Structure characterizations reveal that the Ru atoms are embedded into the Co substrate as isolated active sites with a planar symmetric and Z-direction asymmetric coordination structure, obtaining an optimal 4 d z 2 modulated electronic structure. Hydrogen sensor and temperature program desorption (TPD) tests demonstrate the enhanced Ru-H interactions in RuCo ANSs compared to those in pure Ru nanoparticles. As a result, the RuCo ANSs reach an ultra-low overpotential of 10 mV at 10 mA cm-2 and a Tafel slope of 20.6 mV dec-1 in 1 M KOH, outperforming that of the commercial Pt/C. This holistic work provides a new insight to promote alkaline HER by optimizing the metal-H binding energy of active sites.

17.
Proc Biol Sci ; 288(1949): 20210343, 2021 04 28.
Artículo en Inglés | MEDLINE | ID: mdl-33878923

RESUMEN

The observed patterns and underlying mechanisms of elevational beta-diversity have been explored intensively, but multi-dimensional comparative studies remain scarce. Herein, across distinct beta-diversity components, dimensions and species groups, we designed a multi-faceted comparative framework aiming to reveal the general rules in the observed patterns and underlying causes of elevational beta-diversity. We have found that: first, the turnover process dominated altitudinal patterns of species beta-diversity (ßsim > ßsne), whereas the nestedness process appeared relatively more important for elevational trait dissimilarity (ßfuncsim < ßfuncsne); second, the taxonomic turnover was relative higher than its phylogenetic and functional analogues (ßsim > ßphylosim/ßfuncsim), conversely, nestedness-resultant trait dissimilarity tended to be higher than the taxonomic and phylogenetic measures (ßfuncsne > ßsne/ßphylosne); and third, as elevational distance increased, the contradicting dynamics of environmental filtering and limiting similarity have jointly led the elevational patterns of beta-diversity, especially at taxonomic dimension. Based on these findings, we infer that the species turnover among phylogenetic relatives sharing similar functional attributes appears to be the main cause of shaping the altitudinal patterns of multi-dimensional beta-diversity. Owing to the methodological limitation in the randomization approach, currently, it remains extremely challenging to distinguish the influence of the neutral process from the offset between opposing niche-based processes. Despite the complexities and uncertainties during species assembling, with a multi-dimensional comparative perspective, this work offers us several important commonalities of elevational beta-diversity dynamics.


Asunto(s)
Biodiversidad , Fenotipo , Filogenia
18.
Opt Lett ; 46(1): 5-8, 2021 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-33362008

RESUMEN

Cu2-xS nanoparticles (NPs) demonstrate unique tunable localized surface plasmon resonance (LSPR) and nonlinear optical properties, which are promising materials for photoelectric and display devices. In this work, we present highly improved upconversion luminescence (UCL) in the NaYF4:Yb3+, Er3+@NaYF4:Yb3+, Nd3+@Cu2-xS core-shell structure. The UCL enhancement is systemically studied under excitation of multi-wavelengths 808, 980, and 1540 nm, due to the broadband nature of Cu2-xS LSPR. Two different mechanisms synergistically contribute to the UCL enhancement, namely, the LSPR effect and two-photon effect, which lead to the extraordinary power dependence of UCL. UCL enhancement as high as 12-fold is achieved in the core-shell upconversion NPs (UCNPs). The core-shell NPs are printed on a paper substrate using a nano-printing technique, displaying different colors irradiated by different near-infrared light, and have potential applications in anti-counterfeiting, encryption, and display fields. These findings provide a method to design and optimize luminescent materials and demonstrate potential applications of plasmonic semiconductors and UCNPs.

19.
Front Zool ; 18(1): 14, 2021 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-33771163

RESUMEN

BACKGROUND: Understanding the impacts of past and contemporary climate change on biodiversity is critical for effective conservation. Amphibians have weak dispersal abilities, putting them at risk of habitat fragmentation and loss. Both climate change and anthropogenic disturbances exacerbate these risks, increasing the likelihood of additional amphibian extinctions in the near future. The giant spiny frog (Quasipaa spinosa), an endemic species to East Asia, has faced a dramatic population decline over the last few decades. Using the giant spiny frog as an indicator to explore how past and future climate changes affect landscape connectivity, we characterized the shifts in the suitable habitat and habitat connectivity of the frog. RESULTS: We found a clear northward shift and a reduction in the extent of suitable habitat during the Last Glacial Maximum for giant spiny frogs; since that time, there has been an expansion of the available habitat. Our modelling showed that "overwarm" climatic conditions would most likely cause a decrease in the available habitat and an increase in the magnitude of population fragmentation in the future. We found that the habitat connectivity of the studied frogs will decrease by 50-75% under future climate change. Our results strengthen the notion that the mountains in southern China and the Sino-Vietnamese transboundary regions can act as critical refugia and priority areas of conservation planning going forward. CONCLUSIONS: Given that amphibians are highly sensitive to environmental changes, our findings highlight that the responses of habitat suitability and connectivity to climate change can be critical considerations in future conservation measures for species with weak dispersal abilities and should not be neglected, as they all too often are.

20.
Transfus Apher Sci ; 60(6): 103277, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34563458

RESUMEN

OBJECTIVE: The goal of this study was to predict the probability of transfusion of red blood cells and the volume of blood consumption based on the clinical characteristics of patients before surgery. METHODS: The medical records of 565 patients over 65 years old who underwent posterior lumbar surgery and 586 patients over 65 years old receiving femoral fracture surgery were reviewed. The clinical characteristics of the patients were subjected to multivariate regression analysis. The scores of these factors' influences on intraoperative red blood cells infusion were based on the odds ratio of each multivariate risk factor. Non-linear regression was performed to predict the probability of intraoperative blood transfusion and the volume of blood used for patients with different scores. RESULTS: The factors that significantly influenced blood use during lumbar spinal stenosis and femoral fracture surgery in aged patients(P < 0.05) included age, body mass index, abnormal coagulation function, preoperative hemoglobin, administration of antithrombotic drugs, multisegmental lesions of the lumbar spine, femoral shaft fracture, secondary lumbar surgery and the time from fracture to surgery exceeding 48 h. According to our risk scoring system, patients of posterior lumbar surgery scored 0-10 and patients of femoral fracture had a score of 0-12. More than 50 % of patients receiving an intraoperative red blood cells transfusion during surgery scored>1. CONCLUSION: The scoring system can be used as a predictive model for the probability of red blood cells transfusion and the blood volume in aged patients undergoing lumbar spinal stenosis and femoral fracture surgeries.


Asunto(s)
Transfusión Sanguínea/métodos , Fracturas del Fémur/cirugía , Fracturas del Fémur/terapia , Estenosis Espinal/cirugía , Estenosis Espinal/terapia , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Probabilidad
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