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1.
Nature ; 624(7990): 69-73, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37938775

RESUMO

All-perovskite tandem solar cells hold great promise in surpassing the Shockley-Queisser limit for single-junction solar cells1-3. However, the practical use of these cells is currently hampered by the subpar performance and stability issues associated with mixed tin-lead (Sn-Pb) narrow-bandgap perovskite subcells in all-perovskite tandems4-7. In this study, we focus on the narrow-bandgap subcells and develop an all-in-one doping strategy for them. We introduce aspartate hydrochloride (AspCl) into both the bottom poly(3,4-ethylene dioxythiophene)-poly(styrene sulfonate) and bulk perovskite layers, followed by another AspCl posttreatment. We show that a single AspCl additive can effectively passivate defects, reduce Sn4+ impurities and shift the Fermi energy level. Additionally, the strong molecular bonding of AspCl-Sn/Pb iodide and AspCl-AspCl can strengthen the structure and thereby improve the stability of Sn-Pb perovskites. Ultimately, the implementation of AspCl doping in Sn-Pb perovskite solar cells yielded power conversion efficiencies of 22.46% for single-junction cells and 27.84% (27.62% stabilized and 27.34% certified) for tandems with 95% retention after being stored in an N2-filled glovebox for 2,000 h. These results suggest that all-in-one AspCl doping is a favourable strategy for enhancing the efficiency and stability of single-junction Sn-Pb perovskite solar cells and their tandems.

2.
Nano Lett ; 24(20): 5975-5983, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38726841

RESUMO

In the emerging two-dimensional organic-inorganic hybrid perovskites, the electronic structures and carrier behaviors are strongly impacted by intrinsic electron-phonon interactions, which have received inadequate attention. In this study, we report an intriguing phenomenon of negative carrier diffusion induced by electron-phonon coupling in (2T)2PbI4. Theoretical calculations reveal that the electron-phonon coupling drives the band alignment in (2T)2PbI4 to alternate between type I and type II heterostructures. As a consequence, photoexcited holes undergo transitions between the organic ligands and inorganic layers, resulting in abnormal carrier transport behavior compared to other two-dimensional hybrid perovskites. These findings provide valuable insights into the role of electron-phonon coupling in shaping the band alignments and carrier behaviors in two-dimensional hybrid perovskites. They also open up exciting avenues for designing and fabricating functional semiconductor heterostructures with tailored properties.

3.
Nano Lett ; 24(9): 2681-2688, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38408023

RESUMO

Perovskite light-emitting diodes (PeLEDs) have emerged as promising candidates for lighting and display technologies owing to their high photoluminescence quantum efficiency and high carrier mobility. However, the performance of planar PeLEDs is limited by the out-coupling efficiency, predominantly governed by photonic losses at device interfaces. Most notably, the plasmonic loss at the metal electrode interfaces can account for up to 60% of the total loss. Here, we investigate the use of plasmonic nanostructures to improve the light out-coupling in PeLEDs. By integrating these nanostructures with PeLEDs, we have demonstrated an effectively reduced plasmonic loss and enhanced light out-coupling. As a result, the nanostructured PeLEDs exhibit an average 1.5-fold increase in external quantum efficiency and an ∼20-fold improvement in device lifetime. This finding offers a generic approach for enhancing light out-coupling, promising great potential to go beyond existing performance limitations.

4.
BMC Med Imaging ; 24(1): 92, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38641591

RESUMO

BACKGROUND: The study aimed to develop and validate a deep learning-based Computer Aided Triage (CADt) algorithm for detecting pleural effusion in chest radiographs using an active learning (AL) framework. This is aimed at addressing the critical need for a clinical grade algorithm that can timely diagnose pleural effusion, which affects approximately 1.5 million people annually in the United States. METHODS: In this multisite study, 10,599 chest radiographs from 2006 to 2018 were retrospectively collected from an institution in Taiwan to train the deep learning algorithm. The AL framework utilized significantly reduced the need for expert annotations. For external validation, the algorithm was tested on a multisite dataset of 600 chest radiographs from 22 clinical sites in the United States and Taiwan, which were annotated by three U.S. board-certified radiologists. RESULTS: The CADt algorithm demonstrated high effectiveness in identifying pleural effusion, achieving a sensitivity of 0.95 (95% CI: [0.92, 0.97]) and a specificity of 0.97 (95% CI: [0.95, 0.99]). The area under the receiver operating characteristic curve (AUC) was 0.97 (95% DeLong's CI: [0.95, 0.99]). Subgroup analyses showed that the algorithm maintained robust performance across various demographics and clinical settings. CONCLUSION: This study presents a novel approach in developing clinical grade CADt solutions for the diagnosis of pleural effusion. The AL-based CADt algorithm not only achieved high accuracy in detecting pleural effusion but also significantly reduced the workload required for clinical experts in annotating medical data. This method enhances the feasibility of employing advanced technological solutions for prompt and accurate diagnosis in medical settings.


Assuntos
Aprendizado Profundo , Derrame Pleural , Humanos , Radiografia Torácica/métodos , Estudos Retrospectivos , Radiografia , Derrame Pleural/diagnóstico por imagem
5.
Eur Heart J ; 44(45): 4796-4807, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37585426

RESUMO

BACKGROUND AND AIMS: Patients with left-sided breast cancer receive a higher mean heart dose (MHD) after radiotherapy, with subsequent risk of ischaemic heart disease. However, the optimum dosimetric predictor among cardiac substructures has not yet been determined. METHODS AND RESULTS: This study retrospectively reviewed 2158 women with breast cancer receiving adjuvant radiotherapy. The primary endpoint was a major ischaemic event. The dose-volume parameters of each delineated cardiac substructure were calculated. The risk factors for major ischaemic events and the association between MHD and major ischaemic events were analysed by Cox regression. The optimum dose-volume predictors among cardiac substructures were explored in multivariable models by comparing performance metrics of each model. At a median follow-up of 7.9 years (interquartile range 5.6-10.8 years), 89 patients developed major ischaemic events. The cumulative incidence rate of major ischaemic events was significantly higher in left-sided disease (P = 0.044). Overall, MHD increased the risk of major ischaemic events by 6.2% per Gy (hazard ratio 1.062, 95% confidence interval 1.01-1.12; P = 0.012). The model containing the volume of the left ventricle receiving 25 Gy (LV V25) with the cut-point of 4% presented with the best goodness of fit and discrimination performance in left-sided breast cancer. Age, chronic kidney disease, and hyperlipidaemia were also significant risk factors. CONCLUSION: Risk of major ischaemic events exist in the era of modern radiotherapy. LV V25 ≥ 4% appeared to be the optimum parameter and was superior to MHD in predicting major ischaemic events. This dose constraint could aid in achieving better heart protection in breast cancer radiotherapy, though a further validation study is warranted.


Assuntos
Neoplasias da Mama , Neoplasias Unilaterais da Mama , Feminino , Humanos , Neoplasias Unilaterais da Mama/radioterapia , Estudos Retrospectivos , Neoplasias da Mama/radioterapia , Dosagem Radioterapêutica , Coração , Doses de Radiação
6.
Sensors (Basel) ; 24(6)2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38544212

RESUMO

With the development of the mobile network communication industry, 5G has been widely used in the consumer market, and the application of 5G technology for indoor positioning has emerged. Like most indoor positioning techniques, the propagation of 5G signals in indoor spaces is affected by noise, multipath propagation interference, installation errors, and other factors, leading to errors in 5G indoor positioning. This paper aims to address these issues by first constructing a 5G indoor positioning dataset and analyzing the characteristics of 5G positioning errors. Subsequently, we propose a 5G Positioning Error Correction Neural Network (5G-PECNN) based on neural networks. This network employs a multi-level fusion network structure designed to adapt to the error characteristics of 5G through adaptive gradient descent. Experimental validation demonstrates that the algorithm proposed in this paper achieves superior error correction within the error region, significantly outperforming traditional neural networks.

7.
Nano Lett ; 22(10): 3961-3968, 2022 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-35507685

RESUMO

Circularly polarized light (CPL) is essential for optoelectronic and chiro-spintronic applications. Hybrid perovskites, as star optoelectronic materials, have demonstrated CPL activity, which is, however, mostly limited to chiral perovskites. Here, we develop a simple, general, and efficient strategy to stimulate CPL activity in achiral perovskites, which possess rich species, efficient luminescence, and tunable bandgaps. With the formation of van der Waals heterojunctions between chiral and achiral perovskites, a nonequilibrium spin population and thus CPL activity are realized in achiral perovskites by receiving spin-polarized electrons from chiral perovskites. The polarization degree of room-temperature CPL in achiral perovskites is at least one order of magnitude higher than in chiral ones. The CPL polarization degree and emission wavelengths of achiral perovskites can be flexibly designed by tuning chemical compositions, operating temperature, or excitation wavelengths. We anticipate that unlimited types of achiral perovskites can be endowed with CPL activity, benefiting their applications in integrated CPL sources and detectors.

8.
Angew Chem Int Ed Engl ; 62(19): e202218546, 2023 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-36853171

RESUMO

The liquid-air interface offers a platform for the in-plane growth of free-standing materials. However, it is rarely used for inorganic perovskites and ultrathin non-layered perovskites. Herein the liquid-air interfacial synthesis of inorganic perovskite nanosheets (Cs3 Bi2 I9 , Cs3 Sb2 I9 ) is achieved simply by drop-casting the precursor solution with only the addition of iodine. The products are inaccessible without iodine addition. The thickness and lateral size of these nanosheets can be adjusted through the iodine concentration. The high volatility of the iodine spontaneously drives precursors that normally stay in the liquid to the liquid-air interface. The iodine also repairs in situ iodine vacancies during perovskite growth, giving enhanced optical and optoelectronic properties. The liquid-air interfacial growth of ultrathin perovskites provides multi-degree-of-freedom for constructing perovskite-based heterostructures and devices at atomic scale.

9.
Small ; 18(44): e2204317, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36148858

RESUMO

Van der Waals semiconducting heterostructures, known as stacks of atomically thin transition-metal dichalcogenide (TMD) layers, have recently been reported as new quantum materials with fascinating optoelectronic properties and novel functionalities. These discoveries are significantly related to the interfacial carrier dynamics of the excited states. Carrier dynamics have been reported to be predominantly driven by the ultrafast charge transfer (CT) process; however, the energy transfer (ET) process remains elusive. Herein, the ET process in MoS2 /WS2 heterostructures via transient absorption microscopy is reported. By analyzing the ultrafast dynamics using various MoS2 /WS2 interfaces, an ET rate of ≈240 fs is obtain, which is not trivial to the CT process. This study elucidates the role of the ET process in interfacial carrier dynamics and provides guidance for engineering interfaces for optoelectronic and quantum applications of TMD heterostructures.

10.
Bioorg Med Chem Lett ; 60: 128549, 2022 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-35041943

RESUMO

BTK is a tyrosine kinase playing an important role in B cell and myeloid cell functions through B cell receptor (BCR) signaling and Fc receptor (FcR) signaling. Selective inhibition of BTK has the potential to provide therapeutical benefits to patients suffering from autoimmune diseases. Here we report the design, optimization, and characterization of novel potent and highly selective covalent BTK inhibitors. Starting from a piperazinone hit derived from a selective reversible inhibitor, we solved the whole blood cellular potency issue by introducing an electrophilic warhead to reach Cys481. This design led to a covalent irreversible BTK inhibitor series with excellent kinase selectivity as well as good whole blood CD69 cellular potency. Optimization of metabolic stability led to representative compounds like 42, which demonstrated strong cellular target occupancy and inhibition of B-cell proliferation measured by proximal and distal functional activity.


Assuntos
Tirosina Quinase da Agamaglobulinemia/antagonistas & inibidores , Piperazinas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Tirosina Quinase da Agamaglobulinemia/metabolismo , Linfócitos B/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Estrutura Molecular , Piperazinas/síntese química , Piperazinas/química , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Relação Estrutura-Atividade
11.
Biochem Biophys Res Commun ; 574: 39-47, 2021 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-34438345

RESUMO

Ferroptosis has been identified as an important role in damaged heart. Meanwhile, statin therapy has been reported to be beneficial for the treatment of heart failure(HF) under different conditions. However, the beneficial effects of statin treatment on regulation of ferroptosis in failing heart is unveiled. The aim of this study is to explore the protective efficacy of atorvastatin against the ferroptosis related signaling pathway in isoproterenol(ISO)-induced HF. We found that ATV and ferrostatin-1(Fer-1,as a positive control) significantly improved ISO-decreased cell viability and cell survival by reducing oxidative stress and Fe2+-dependent lipid peroxidation in H9C2 cells. Additionally, ISO triggered marked ferritinophagy accompanied by up-regulating protein levels of LC3BII,NCOA4 and Beclin1 and down-regulating protein levels of P62 and FTH1 in damaged cells, which nevertheless was significantly blocked by administration of ATV and these results were in parallel with the results obtained after 3-methyadenine(3-MA) treatment. Consistently, C57BL/6J mice were used in used in this study and administered 5 mg/kg/day ISO for 2 weeks to simulate cardiac injury. 20 mg/kg/day ATV treatment for 2 weeks simultaneously markedly improved cardiac dysfunction and remodeling induced by ISO attack. ATV showed significantly protective effects through suppressing the activation of ferroptosis related signaling, as evidenced by decreasing the mRNA levels of PTGS2(a marker of ferroptosis), contents of malonaldehyde and protein levels of NOX4 and increasing the contents of glutathione(GSH), the ratio of GSH/GSSG and protein levels of GPX4 and SLC7A11. Moreover, ISO evidently triggered degradation of FTH1 in failing heart. However, ATV significantly prevented these changes in damaged heart. Overall, these results reveal atorvastatin suppresses ferroptosis and exhibits protective effect on failing myocardium of mice after ISO insult though inhibiting ferritinophagy-mediated ferroptosis, which might be a potential therapeutic strategy in the prevention of ISO-associated cardiomyopathy.


Assuntos
Atorvastatina/farmacologia , Ferroptose/efeitos dos fármacos , Isoproterenol/farmacologia , Miócitos Cardíacos/efeitos dos fármacos , Animais , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Miócitos Cardíacos/metabolismo , Ratos
12.
Sensors (Basel) ; 21(4)2021 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-33562381

RESUMO

Cellular vehicle-to-everything (C-V2X) is essential in enabling safe, reliable, and efficient transportation services. It serves as serve as the foundation for vehicles to communicate with each other and everything around them. One fundamental element in C-V2X is positioning, namely extracting the vehicle's absolute and relative positions concerning other objects such as buildings, pedestrians, traffic signs, and other vehicles. However, its feasibility in enabling vehicular positioning has not been fully explored yet. In this paper, key performance indicators (KPIs) for C-V2X positioning have been described firstly. Then positioning challenges and conventional positioning methods for C-V2X are reviewed. Afterward, two user equipment (UE)-based and UE-assisted C-V2X positioning architectures are proposed, and key technologies are also described. Lastly, testing and typical application cases are provided.

13.
J Am Chem Soc ; 142(38): 16254-16264, 2020 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-32845129

RESUMO

Understanding semiconductor surface properties and manipulating them chemically are critical for improving their performance in optoelectronic devices. Hybrid halide perovskites have emerged as an exciting class of highly efficient solar materials; however, their device performance could be limited by undesirable surface properties that impede carrier transport and induce recombination. Here we show that surface functionalization of methylammonium lead iodide (MAPbI3) perovskite with phenethylammonium iodide (PEAI), a commonly employed spacer cation in two-dimensional halide perovskites, can enhance carrier diffusion in the near-surface regions and reduce defect density by more than 1 order of magnitude. Using transient transmission and reflection microscopy, we selectively imaged the transport of the carriers near the (001) surface and in the bulk for single-crystal MAPbI3 microplates. The surface functionalization increases the diffusion coefficient of the carriers in the 40 nm subsurface region from ∼0.6 cm2 s-1 to ∼1.0 cm2 s-1, similar to the value for bulk carriers. These results suggest the PEA ligands are effective in reducing surface defect and phonon scattering and shed light on the mechanisms for enhancing photophysical properties and improving solar cell efficiency.

14.
Toxicol Appl Pharmacol ; 402: 115132, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32659285

RESUMO

Current studies aimed at investigating the association between atorvastatin therapy and insulin resistance (IR) appear to be controversial. IR is considered to be an important contributor to inducing cardiac dysfunction through multiple signals. The paradoxical cardiotoxicity of atorvastatin reported under different conditions suggests that the association between atorvastatin treatment, insulin resistance and cardiac function should be clarified further. In this study, C57BL/6 J male mice were fed a high-fat diet (HD) or standard chow diet (SD) for 12 weeks and subsequently randomly divided into four groups: the SD-Control (SD-C) and HD-Control (HD-C) groups treated with saline for 10 months and the HD-A and HD-A + N groups treated with atorvastatin (20 mg/kg/day) alone or atorvastatin combined with nicotinamide (NAM, 1 g/kg/day) for 10 months. Although no significant changes in systolic function and structure were observed between the four groups of mice at an age of 46 or 58 weeks, respectively, long-term treatment with atorvastatin alone or atorvastatin and NAM combination significantly retarded the HD-induced IR and diastolic dysfunction and attenuated both cardiac and hepatic fibrosis in obese mice possibly by regulating the cleavage of osteopontin and then controlling profibrotic activity. Changes in cardiac function and structure were similar between the HD-A and HD-A + N groups; however, mice in the HD-A + N group exhibited better glucose control and marked reduction in body weight and hepatic lipid accumulation. Thus, these results suggest that long-term treatment with atorvastatin or the combination of atorvastatin and nicotinamide may be alternative therapies due to their beneficial effects on IR and diastolic function.


Assuntos
Atorvastatina/uso terapêutico , Resistência à Insulina , Niacinamida/uso terapêutico , Obesidade/induzido quimicamente , Disfunção Ventricular Esquerda/tratamento farmacológico , Animais , Anticolesterolemiantes/administração & dosagem , Anticolesterolemiantes/uso terapêutico , Atorvastatina/administração & dosagem , Glicemia/efeitos dos fármacos , Dieta Hiperlipídica/efeitos adversos , Quimioterapia Combinada , Insulina/sangue , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Niacinamida/administração & dosagem , Distribuição Aleatória , Complexo Vitamínico B/administração & dosagem , Complexo Vitamínico B/uso terapêutico
15.
Angew Chem Int Ed Engl ; 59(49): 22246-22251, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32815276

RESUMO

In photocatalysis, the Schottky barrier in metal-semiconductor hybrids is known to promote charge separation, but a core-shell structure always leads to a charge build-up and eventually shuts off the photocurrent. Here, we show that Au-Cu2 O hybrid nanostructures can be continuously tuned, particularly when the Cu2 O domains are single-crystalline. This is in contrast to the conventional systems, where the hybrid configuration is mainly determined by the choice of materials. The distal separation of the Au-Cu2 O domains in Janus nanostructures leads to enhanced charge separation and a large improvement of the photocurrent. The activity of the Au-Cu2 O Janus structures is 5 times higher than that of the core-shell structure, and 10 times higher than that of the neat Cu2 O nanocubes. The continuous structural tuning allows to study the structure-property relationship and an optimization of the photocatalytic performance.

16.
BMC Bioinformatics ; 20(1): 239, 2019 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-31088348

RESUMO

BACKGROUND: With advancements in high-throughput technologies, the cost of obtaining expression profiles of both mRNA and microRNA in the same individual has substantially decreased. Integrated analysis of these profiles can help to elucidate the functional effects of RNA expression in complex diseases, such as cancer. However, fundamental discrepancies are observed in the results from microRNA-mRNA target gene prediction algorithms, and few packages can be used to analyze microRNA and mRNA expression levels simultaneously. RESULTS: To address these issues, an R package, anamiR, was developed. A total of 10 experimental/prediction databases were integrated. Two analytical functions are provided in anamiR, including the single marker test and functional gene set enrichment analysis, and several parameters can be changed by users. Here we demonstrate the potential application of the anamiR package to 2 publicly available microarray datasets. CONCLUSION: The anamiR package is effective for an integrated analysis of both RNA and microRNA profiles. By characterizing biological functions and signaling pathways, this package helps identify dysregulated genes/miRNAs from biological and medical experiments. The source code and manual of the anamiR package are freely available at https://bioconductor.org/packages/release/bioc/html/anamiR.html .


Assuntos
Perfilação da Expressão Gênica/métodos , MicroRNAs/genética , Algoritmos , Humanos
19.
Lasers Surg Med ; 50(4): 324-332, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29095506

RESUMO

BACKGROUND AND PURPOSE: The purpose of this study was to investigate the subacute effects of Rose Bengal (RB) and 532 nm green light-induced photochemical crosslinking (RB-PCL) on rabbit thin corneal stability and safety in vivo. MATERIALS AND METHODS: Rabbit thin corneal models with 250 µm thickness were created by photorefractive keratectomy surgery. Photochemical crosslinking with green light (wavelength 532 nm) at an illumination intensity of 0.4 W/cm2 for 250 s (100 J/cm2 ) was performed, followed by antibiotic treatment and slit lamp monitoring for four weeks. At the end of week four, corneal biomechanical stiffness, biochemical resistance to collagenase digestion, and corneal cellular morphology were assessed. The penetration depth of RB into the corneal stromal was measured by confocal microscopy. RESULTS: At the end of week 4, RB-PCL had increased corneal tensile strength by an average 2.5-fold and had extended the corneal collagenase digestion time from 10.17 ± 2.93 to 15.83 ± 2.64 days. RB penetrated approximately 90 µm into the corneal stroma. RB-PCL did not alter the corneal endothelial and stromal morphology at the cellular or subcellular levels, according to electron microscopic examination. CONCLUSIONS: RB and 532 nm green light irradiation effectively induced crosslinking in rabbit thin cornea, by increasing both the biomechanical stiffness and the biochemical resistance without evidence of morphological damage to the corneal endothelium or stroma. This study demonstrated the efficacy of RB-PCL in strengthening thin cornea at four weeks after the treatment, providing a potential and possibly better option for treating corneal ectasia disorders in cases where corneal thickness is less than 400 µm. Lasers Surg. Med. 50:324-332, 2018. © 2017 Wiley Periodicals, Inc.


Assuntos
Doenças da Córnea/diagnóstico por imagem , Doenças da Córnea/cirurgia , Cirurgia da Córnea a Laser/métodos , Fármacos Fotossensibilizantes/farmacologia , Rosa Bengala/farmacologia , Animais , Córnea/cirurgia , Córnea/ultraestrutura , Doenças da Córnea/patologia , Modelos Animais de Doenças , Ceratectomia/métodos , Masculino , Microscopia Confocal/métodos , Microscopia Eletrônica de Transmissão/métodos , Coelhos , Distribuição Aleatória , Sensibilidade e Especificidade , Resistência à Tração , Cicatrização/fisiologia
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