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1.
Eur J Neurosci ; 59(11): 3045-3060, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38576168

RESUMEN

Dual tasks (DTs) combining walking with a cognitive task can cause various levels of cognitive-motor interference, depending on which brain resources are recruited in each case. However, the brain activation and functional connectivity underlying cognitive-motor interferences remain to be elucidated. Therefore, this study investigated the neural correlation during different DT conditions in 40 healthy young adults (mean age: 27.53 years, 28 women). The DTs included walking during subtraction or N-Back tasks. Cognitive-motor interference was calculated, and brain activation and functional connectivity were analysed. Portable functional near-infrared spectroscopy was utilized to monitor haemodynamics in the prefrontal cortex (PFC), motor cortex and parietal cortex during each task. Walking interference (decrease in walking speed during DT) was greater than cognitive interference (decrease in cognitive performance during DT), regardless of the type of task. Brain activation in the bilateral PFC and parietal cortex was greater for walking during subtraction than for standing subtraction. Furthermore, brain activation was higher in the bilateral motor and parietal and PFCs for walking during subtraction than for walking alone, but only increased in the PFC for walking during N-Back. Coherence between the bilateral lateral PFC and between the left lateral PFC and left motor cortex was significantly greater for walking during 2-Back than for walking. The PFC, a critical brain region for organizing cognitive and motor functions, played a crucial role in integrating information coming from multiple brain networks required for completing DTs. Therefore, the PFC could be a potential target for the modulation and improvement of cognitive-motor functions during neurorehabilitation.


Asunto(s)
Cognición , Desempeño Psicomotor , Espectroscopía Infrarroja Corta , Humanos , Femenino , Espectroscopía Infrarroja Corta/métodos , Masculino , Adulto , Cognición/fisiología , Desempeño Psicomotor/fisiología , Adulto Joven , Caminata/fisiología , Corteza Motora/fisiología , Corteza Prefrontal/fisiología , Corteza Prefrontal/diagnóstico por imagen , Lóbulo Parietal/fisiología
2.
3.
Biochem Biophys Res Commun ; 519(2): 330-336, 2019 11 05.
Artículo en Inglés | MEDLINE | ID: mdl-31514997

RESUMEN

Pseudorabies virus (PRV), the agent of pseudorabies, has raised considerable attention since 2011 due to the outbreak of emerging PRV variants in China. In the present study, we obtained two monoclonal antibodies (mAbs) known as 2E5 and 5C3 against the glycoprotein E (gE) of a PRV variant (JS-2012 strain). The two mAbs reacted with wild PRV but not the vaccine strain (gE-deleted virus). The 2E5 was located in 161RLRRE165, which was conserved in almost of all PRV strains, while 5C3 in 148EMGIGDY154 was different from almost of all genotype I PRV, in which the 149th amino acid is methionine (M) instead of arginine (R). The two epitopes peptides located in the hydrophilic region and reacted with positive sera against genotype II PRV (JS-2012), which suggests they were likely dominant B-cell epitopes. Furthermore, the mutant peptide 148ERGIGDY154 (genotype I) did not react with the mAb 5C3 or positive sera against genotype II PRV (JS-2012). In conclusion, both mAb 2E5 and 5C3 could be used to identify wild PRV strains from vaccine strains, and mAb 5C3 and the epitope peptide of 5C3 might be used for epidemiological investigation to distinguish genotype II from genotype I PRV.


Asunto(s)
Anticuerpos Monoclonales/inmunología , Epítopos de Linfocito B/inmunología , Herpesvirus Suido 1/química , Proteínas del Envoltorio Viral/inmunología , Animales , Línea Celular , Chlorocebus aethiops , Herpesvirus Suido 1/efectos de los fármacos , Herpesvirus Suido 1/inmunología , Ratones , Péptidos/farmacología , Porcinos , Células Vero , Proteínas del Envoltorio Viral/antagonistas & inhibidores
4.
Virus Genes ; 55(3): 381-393, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30927185

RESUMEN

Bacteriophages often constitute the majority of periodontal viral communities, but phages that infect oral bacteria remain uncharacterized. Here, we present the genetic analysis of the genome of a novel siphovirus, named Siphoviridae_29632, which was isolated from a patient with periodontitis using a viral metagenomics-based approach. Among 43 predicted open reading frames (ORFs) in the genome, the viral genes encoding structural proteins were distinct from the counterparts of other viruses, although a distant homology is shared among viral morphogenesis proteins. A total of 28 predicted coding sequences had significant homology to other known phage ORF sequences. In addition, the prevalence of Siphoviridae_29632 in a cohort of patients with chronic periodontitis was 41.67%, which was significantly higher than that in the healthy group (4.55%, P < 0.001), suggesting that this virus as well as its hosts may contribute to the ecological environment favored for chronic periodontitis.


Asunto(s)
Bacteriófagos/genética , Periodontitis Crónica/virología , Bolsa Periodontal/virología , Siphoviridae/genética , Bacteriófagos/aislamiento & purificación , Bacteriófagos/patogenicidad , Periodontitis Crónica/genética , Periodontitis Crónica/microbiología , Genoma Viral/genética , Genómica , Humanos , Metagenómica , Bolsa Periodontal/genética , Bolsa Periodontal/microbiología , Filogenia , Siphoviridae/aislamiento & purificación
5.
Biochem Biophys Res Commun ; 504(1): 157-163, 2018 09 26.
Artículo en Inglés | MEDLINE | ID: mdl-30172377

RESUMEN

Porcine reproductive and respiratory syndrome virus (PRRSV) has been a major threat to global industrial pig farming ever since its emergence in the late 1980s. Identification of sustainable and effective control measures against PRRSV transmission is a pressing problem. The nucleocapsid (N) protein of PRRSV is specifically localized in the cytoplasm and nucleus of virus-infected cells which is important for PRRSV replication. In the current study, a new host restricted factor, Moloney leukemia virus 10-like protein (MOV10), was identified as an inhibitor of PRRSV replication. N protein levels and viral replication were significantly reduced in Marc-145 cells stably overexpressing MOV10 compared with those in wild-type Marc-145 cells. Adsorption experiments revealed that MOV10 did not affect the attachment and internalization of PRRSV. Co-immunoprecipitation and immunofluorescence co-localization analyses showed that MOV10 interacted and co-localized with the PRRSV N protein in the cytoplasm. Notably, MOV10 affected the distribution of N protein in the cytoplasm and nucleus, leading to the retention of N protein in the former. Taken together, these findings demonstrate for the first time that MOV10 inhibits PRRSV replication by restricting the nuclear import of N protein. These observations have great implications for the development of anti-PRRSV drugs and provide new insight into the role of N protein in PRRSV biology.


Asunto(s)
Citoplasma/metabolismo , Proteínas de la Nucleocápside/química , Virus del Síndrome Respiratorio y Reproductivo Porcino/fisiología , ARN Helicasas/metabolismo , Replicación Viral , Crianza de Animales Domésticos , Animales , Línea Celular , Chlorocebus aethiops , Replicación del ADN , Células HEK293 , Humanos , Virus de la Leucemia Murina de Moloney/metabolismo , Síndrome Respiratorio y de la Reproducción Porcina/metabolismo , Unión Proteica , Porcinos , Proteínas no Estructurales Virales/metabolismo
6.
Cancer Cell Int ; 18: 149, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30275772

RESUMEN

BACKGROUND: Marsdenia tenacissima is an herb medicine which has been utilized to treat malignant diseases for decades. The M. tenacissima extract (MTE) shows significant anti-proliferation activity against non-small cell lung cancer (NSCLC) cells, but the underlying mechanisms remain unclear. In this study, we explored the potential anti-proliferation mechanisms of MTE in NSCLC cells in relation to apoptosis as well as autophagy, which are two critical forms to control cancer cell survival and death. METHODS: The proliferation of H1975 and A549 cells was evaluated by MTT assay. Cell apoptosis was assessed by Annexin V and PI staining, Caspase 3 expression and activity. Autophagy flux proteins were detected by Western blot with or without autophagy inducer and inhibitor. Endogenous LC3-II puncta and LysoTracker staining were monitored by confocal microscopy. The formation of autophagic vacuoles was measured by acridine orange staining. ERK is a crucial molecule to interplay with cell autophagy and apoptosis. The role of ERK on cell apoptosis and autophagy influenced by MTE was determined in the presence of MEK/ERK inhibitor U0126. RESULTS: The significant growth inhibition and apoptosis induction were observed in MTE treated NSCLC cells. MTE induced cell apoptosis coexisted with elevated Caspase 3 activity. MTE also impaired autophagic flux by upregulated LC3-II and p62 expression. Autophagy inducer EBSS could not abolish the impaired autophagic flux by MTE, while it was augmented in the presence of autophagy inhibitor Baf A1. The autophagosome-lysosome fusion was blocked by MTE via affecting lysosome function as evidenced by decreased expression of LAMP1 and Cathepsin B. The molecule ERK became hyperactivated after MTE treatment, but the MEK/ERK inhibitor U0126 abrogated autophagy inhibition and apoptosis induction caused by MTE, suggested that ERK signaling pathways partially contributed to cell death caused by MTE. CONCLUSION: Our results demonstrate that MTE caused apoptosis induction as well as autophagy inhibition in NSCLC cells. The activated ERK is partially associated with NSCLC apoptotic and autophagic cell death in response to MTE treatment. The present findings reveal new mechanisms for the anti-tumor activity of MTE against NSCLC.

7.
Virus Genes ; 53(6): 823-830, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28866831

RESUMEN

We describe a novel species of torque teno mini virus called TTMV-204, which was isolated from the gingival epithelium of patients with periodontitis and characterized using viral metagenomics. The sequence of the full genome is 2824 nt in length. Phylogenetic analysis and genetic analyses show classic Betatorquevirus species organization with less than 40% amino acid similarity in ORF1. The prevalence of TTMV-204 in the periodontitis patient population was 18.75% (15/80), which was higher than in periodontally healthy individuals (10.00%, 10/80). However, the difference of the TTMV-204 prevalence between two groups was not statistically significant (p = 0.115). Further investigation is required to determine whether this new virus is associated with inflammation.


Asunto(s)
Epitelio/virología , Encía/virología , Periodontitis/virología , Torque teno virus/genética , Adulto , Aminoácidos/genética , Anelloviridae/genética , Infecciones por Virus ADN/virología , ADN Viral/genética , Femenino , Genoma Viral/genética , Humanos , Masculino , Filogenia , Prevalencia
8.
Arch Virol ; 159(9): 2513-7, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24719194

RESUMEN

The SD0803 strain of the bovine viral diarrhea virus (BVDV) was isolated from a piglet in China in 2008 and has been classified as a novel subgenotype of BVDV-1. To describe the molecular features of this novel subgenotype, we sequenced and characterized the complete genome of the SD0803 virus. The genome is 12,271 bp in length and contains 5' and 3' untranslated regions (UTRs) that flank an open reading frame (ORF) encoding a 3,898-amino-acid polypeptide. The full-length genome of the SD0803 strain shares 78.8% to 83.3% identity with those of other BVDV-1 strains, 70.0% to 70.7% identity with those of BVDV-2 strains, and less than 67.6% identity with those of other pestiviruses. The highest level of shared identity was 83.3% between the complete SD0803 genome and that of the ZM-95 strain of BVDV-1. Phylogenetic analysis of the 5' UTR and the coding sequence for the N-terminal protease fragment of the SD0803 polyprotein indicated that the SD0803 virus is a member of the novel subgenotype BVDV-1q, isolates of which have been identified recently in dairy cattle and camels in China.


Asunto(s)
Virus de la Diarrea Viral Bovina Tipo 1/clasificación , Virus de la Diarrea Viral Bovina Tipo 1/genética , Genoma Viral , Infecciones por Pestivirus/veterinaria , ARN Viral/genética , Análisis de Secuencia de ADN , Porcinos/virología , Regiones no Traducidas 3' , Regiones no Traducidas 5' , Animales , China , Análisis por Conglomerados , Virus de la Diarrea Viral Bovina Tipo 1/aislamiento & purificación , Datos de Secuencia Molecular , Sistemas de Lectura Abierta , Infecciones por Pestivirus/virología , Filogenia , Homología de Secuencia
9.
Sci Rep ; 14(1): 789, 2024 01 08.
Artículo en Inglés | MEDLINE | ID: mdl-38191488

RESUMEN

Music and speech are encountered daily and are unique to human beings. Both are transformed by the auditory pathway from an initial acoustical encoding to higher level cognition. Studies of cortex have revealed distinct brain responses to music and speech, but differences may emerge in the cortex or may be inherited from different subcortical encoding. In the first part of this study, we derived the human auditory brainstem response (ABR), a measure of subcortical encoding, to recorded music and speech using two analysis methods. The first method, described previously and acoustically based, yielded very different ABRs between the two sound classes. The second method, however, developed here and based on a physiological model of the auditory periphery, gave highly correlated responses to music and speech. We determined the superiority of the second method through several metrics, suggesting there is no appreciable impact of stimulus class (i.e., music vs speech) on the way stimulus acoustics are encoded subcortically. In this study's second part, we considered the cortex. Our new analysis method resulted in cortical music and speech responses becoming more similar but with remaining differences. The subcortical and cortical results taken together suggest that there is evidence for stimulus-class dependent processing of music and speech at the cortical but not subcortical level.


Asunto(s)
Música , Humanos , Habla , Acústica , Vías Auditivas , Benchmarking
10.
Math Biosci Eng ; 20(1): 365-382, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36650770

RESUMEN

Accurate segmentation is a basic and crucial step for medical image processing and analysis. In the last few years, U-Net, and its variants, have become widely adopted models in medical image segmentation tasks. However, the multiple training parameters of these models determines high computation complexity, which is impractical for further applications. In this paper, by introducing depthwise separable convolution and attention mechanism into U-shaped architecture, we propose a novel lightweight neural network (DSCA-Net) for medical image segmentation. Three attention modules are created to improve its segmentation performance. Firstly, Pooling Attention (PA) module is utilized to reduce the loss of consecutive down-sampling operations. Secondly, for capturing critical context information, based on attention mechanism and convolution operation, we propose Context Attention (CA) module instead of concatenation operations. Finally, Multiscale Edge Attention (MEA) module is used to emphasize multi-level representative scale edge features for final prediction. The number of parameters in our network is 2.2 M, which is 71.6% less than U-Net. Experiment results across four public datasets show the potential and the dice coefficients are improved by 5.49% for ISIC 2018, 4.28% for thyroid, 1.61% for lung and 9.31% for nuclei compared with U-Net.


Asunto(s)
Núcleo Celular , Procesamiento de Imagen Asistido por Computador , Redes Neurales de la Computación , Glándula Tiroides
11.
JACC Basic Transl Sci ; 8(9): 1081-1097, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37791312

RESUMEN

Sodium-glucose cotransporter 2 (SGLT2) inhibitors reduce epicardial adipose tissue (EAT) in humans, enhancing cardioprotective effects on heart failure and atrial fibrillation. We investigated the direct effect of the SGLT2 inhibitor empagliflozin on human primary epicardial adipocytes and preadipocytes. SGLT2 is primarily expressed in human preadipocytes in the EAT. The expression levels of SGLT2 significantly diminished when the preadipocytes were terminally differentiated. Adipogenesis of preadipocytes was attenuated by empagliflozin treatment without affecting cell proliferation. The messenger RNA levels and secreted protein levels of interleukin 6 and monocyte chemoattractant protein 1 were significantly decreased in empagliflozin-treated adipocytes. Coculture of human induced pluripotent stem cell-derived atrial cardiomyocytes and adipocytes pretreated with or without empagliflozin revealed that empagliflozin significantly suppressed reactive oxygen species. IL6 messenger RNA expression in human EAT showed significant clinically relevant associations. Empagliflozin suppresses human epicardial preadipocyte differentiation/maturation, likely inhibiting epicardial adipogenesis and improving the paracrine secretome profile of EAT, particularly by regulating IL6 expression.

12.
Front Endocrinol (Lausanne) ; 13: 1028429, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36743934

RESUMEN

Ischemia with non-obstructive coronary artery (INOCA) is a blind spot of coronary artery disease (CAD). Such patients are often reassured but offered no specific care, that lead to a heightened risk of adverse cerebrovascular disease (CVD) outcomes. Epicardial adipose tissue (EAT) is proven to correlate independently with CAD and its severity, but it is unknown whether EAT is a specific and sensitive indicator of INOCA. This review focuses on the INOCA epidemiology and related factors, as well as the association between EAT.


Asunto(s)
Enfermedad de la Arteria Coronaria , Humanos , Enfermedad de la Arteria Coronaria/epidemiología , Pericardio , Isquemia , Tejido Adiposo
13.
Front Optoelectron ; 15(1): 49, 2022 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-36637681

RESUMEN

Organic photodiodes (OPDs) have shown great promise for potential applications in optical imaging, sensing, and communication due to their wide-range tunable photoelectrical properties, low-temperature facile processes, and excellent mechanical flexibility. Extensive research work has been carried out on exploring materials, device structures, physical mechanisms, and processing approaches to improve the performance of OPDs to the level of their inorganic counterparts. In addition, various system prototypes have been built based on the exhibited and attractive features of OPDs. It is vital to link the device optimal design and engineering to the system requirements and examine the existing deficiencies of OPDs towards practical applications, so this review starts from discussions on the required key performance metrics for different envisioned applications. Then the fundamentals of the OPD device structures and operation mechanisms are briefly introduced, and the latest development of OPDs for improving the key performance merits is reviewed. Finally, the trials of OPDs for various applications including wearable medical diagnostics, optical imagers, spectrometers, and light communications are reviewed, and both the promises and challenges are revealed.

14.
Health Sci Rep ; 5(5): e757, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-36101718

RESUMEN

Background and Aims: Clinical skills practice is an essential component in standardized residency training. However, traditionally skill training methods are dogmatic and not all residents are exposed to such prescribed situations during their residency. The aims of this study were to evaluate the effectiveness and influence factors of a four-step approach combining situational simulation teaching methods in clinical practice for residents. Methods: Enrolled all second-year residents from the internal medicine base between May 2017 and May 2018 (n = 94), randomly divided into two groups. Forty-eight residents were selected as experimental group, while the others 46 as the control group. Adopted traditional clinical practice method in the teaching and assessment of the control group, while used four-step approach combining situational simulation teaching method in experimental group. We compared the theoretical and skill assessment scores in preclass and postclass. Conducted a satisfaction survey after class and analyzed the influencing factors of the teaching effect evaluation. Results: There were no significant differences in the theoretical and skill assessment scores between experimental group and control group at the beginning. After the class, both the average skill assessment and Direct Observation of Procedural Skills scores of the experimental group were higher than those of the control. Satisfaction survey findings identified that the experimental group expressed higher satisfaction. Logistic regression showed that educational background, "situational simulation mode helps to improve clinical skills training," "helps to maintain attention during learning," and "helps improve the ability to exercise analysis and solve problems" were the influencing factors of learners' satisfaction. Conclusion: The application of four-step approach combining situational simulation teaching methods in the clinical practice of residents can significantly improve skills, thinking ability, decision-making ability, and teaching satisfaction. Therefore, four-step approach combining situational simulation teaching methods is worth promoting in teaching clinical skills for internal medicine residency training.

15.
ACS Appl Mater Interfaces ; 14(27): 31066-31074, 2022 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-35762628

RESUMEN

Organic optoelectronic devices exhibit distinctive photoresponse to the near-infrared (NIR) light and show great potential in many fields. However, the optoelectronic properties of the existing devices hardly meet the technical requirements of new applications such as energy conversion and health sensing, thus raising the demand to develop high-performance NIR organic semiconductors. To address this issue, a new NIR material, namely, BFIC, is designed and synthesized by inserting fluorothieno[3,4-b]thiophene (FTT) as a π-bridge. Since the introduction of FTT can extend the conjugation, stabilize the quinoid resonant structure, and enhance the intramolecular charge transfer, BFIC displays a broad and intense absorption in the NIR region, ranging from 700 to 1050 nm. As a result, the organic solar cell based on BFIC and a polymer donor PTB7-Th realizes a power conversion efficiency of 10.38%. The semitransparent organic solar cell (OSC) shows a power conversion efficiency of 6.15%, accompanied by an average visible transmittance of 38.79% due to the selective photoresponse in the NIR range. The organic photodetector based on PTB7-Th:BFIC delivers a broad spectral response ranging from 330 to 1030 nm with a specific detectivity over 1013 Jones under the self-powered mode, which is one of the highest detectivities among the broad-band organic photodetectors.

16.
Trends Hear ; 26: 23312165221136934, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36384325

RESUMEN

Listening in a noisy environment is challenging, but many previous studies have demonstrated that comprehension of speech can be substantially improved by looking at the talker's face. We recently developed a deep neural network (DNN) based system that generates movies of a talking face from speech audio and a single face image. In this study, we aimed to quantify the benefits that such a system can bring to speech comprehension, especially in noise. The target speech audio was masked with signal to noise ratios of -9, -6, -3, and 0 dB and was presented to subjects in three audio-visual (AV) stimulus conditions: (1) synthesized AV: audio with the synthesized talking face movie; (2) natural AV: audio with the original movie from the corpus; and (3) audio-only: audio with a static image of the talker. Subjects were asked to type the sentences they heard in each trial and keyword recognition was quantified for each condition. Overall, performance in the synthesized AV condition fell approximately halfway between the other two conditions, showing a marked improvement over the audio-only control but still falling short of the natural AV condition. Every subject showed some benefit from the synthetic AV stimulus. The results of this study support the idea that a DNN-based model that generates a talking face from speech audio can meaningfully enhance comprehension in noisy environments, and has the potential to be used as a visual hearing aid.


Asunto(s)
Comprensión , Percepción del Habla , Humanos , Habla , Ruido/efectos adversos , Redes Neurales de la Computación
17.
Brain Imaging Behav ; 15(4): 1868-1875, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32918183

RESUMEN

Acute stress has substantial impact on white matter microstructure of people exposed to trauma. Its long-term consequence and how the brain changes from the stress remain unclear. In this study, we address this issue via diffusion tensor imaging (DTI). Twenty-two trauma-exposed individuals who did not meet post-traumatic stress disorder (PTSD) diagnostic criteria were recruited from the most affected area of Wenchuan earthquake and scanned twice (within twenty-five days and two years after the quake, respectively). Their emotional distress was evaluated with the Self-Rating Anxiety/Depression Scales (SAS/SDS) at both scans. Automatic fiber quantification was used to examine brain microstructure alterations. Correlation analyses were also conducted to investigate relationships between brain microstructure changes and symptom improvement. A group of demographically matched healthy controls (N = 22) from another project were scanned once before the quake using the same imaging protocols as used with trauma-exposed non-PTSD (TENP) participants. Two years after the earthquake, TENP individuals exhibited significantly reduced FA in the parietal portion of left superior longitudinal fasciculus and high FA in the parietal portion of left corticospinal tract. Over the follow-up, increased FA of the left uncinate fasciculus and the left corticospinal tract with parallel reduction of SAS and SDS were observed in TENP. No significant association was found between brain microstructure changes and symptom improvement. These results indicate changes in WM microstructure integrity of TENP brains parallel with symptom improvement over time after acute stress. However, the change would be a long-term process without external intervention.


Asunto(s)
Trastornos por Estrés Postraumático , Sustancia Blanca , Anisotropía , Encéfalo/diagnóstico por imagen , Imagen de Difusión Tensora , Humanos , Imagen por Resonancia Magnética , Sustancia Blanca/diagnóstico por imagen
18.
ACS Appl Mater Interfaces ; 13(43): 51279-51288, 2021 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-34672513

RESUMEN

Non-fullerene acceptors (NFAs) with near-infrared (NIR) absorption show promising advantages in organic solar cells (OSCs). However, only a few NFAs can extend the absorption spectra over 1000 nm, and their photovoltaic performance has been unsatisfactory so far. To address this issue, three new NFAs, namely, 6-IFIC, 6-IF2F, and 6-IF4F, were synthesized by simultaneously introducing π-bridge units and different end groups. The π-bridge unit enlarges the conjugation and planarizes the molecular geometry, leading to intense absorption in the NIR range. The asymmetric configuration provides a large dipole moment, enhances the intermolecular interaction, and tunes the miscibility, consequently being beneficial for achieving a favorable morphology in OSCs. When blended with a donor polymer PTB7-Th, the 6-IF2F-based OSC yields the best power conversion efficiency (PCE) of 11.20%, which is among the highest PCEs based on NFAs with absorption over 1000 nm. More importantly, the absorption of the blend film provides a transparency window in the visible range from 400 and 650 nm. Therefore, the semitransparent OSCs based on these three NFAs can achieve over 28% average visible transmittance.

19.
Chem Commun (Camb) ; 56(77): 11433-11436, 2020 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-32845952

RESUMEN

A new non-fullerene acceptor PDFC is prepared by introducing perylene diimide into the core of an A-DA'D-A architecture. Due to the large conjugation and electron-deficient ability of perylene diimide, PDFC shows strong absorption, suitable energy levels and favorable face-on packing. The optimal device realizes a PCE of 12.56% with one of the highest fill factors (81.3%). A PCE of 9.66% is obtained in a 570 nm thick-film device based on PDFC.

20.
Nanomicro Lett ; 12(1): 84, 2020 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-34138089

RESUMEN

Previous reports of formamidinium/methylamine (FAMA)-mixed halide perovskite solar cells have focused mainly on controlling the morphology of the perovskite film and its interface-for example, through the inclusion of bromine and surface passivation. In this paper, we describe a new processing pathway for the growth of a high-quality bromine-free FAMAPbI3 halide perovskites via the control of intermediate phase. Through low-temperature aging growth (LTAG) of a freshly deposited perovskite film, α-phase perovskites can be seeded in the intermediate phase and, at the same time, prevent beta-phase perovskite to nucleate. After postannealing, large grain-size perovskites with significantly reduced PbI2 presence on the surface can be obtained, thereby eliminating the need of additional surface passivation step. Our pristine LTAG-treated solar cells could provide PCEs of greater than 22% without elaborate use of bromine or an additional passivation layer. More importantly, when using this LTAG process, the growth of the pure alpha-phase FAMAPbI3 was highly reproducible.

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