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1.
Ying Yong Sheng Tai Xue Bao ; 35(3): 687-694, 2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38646756

RESUMO

Understanding land structure change and stability in the process of oasisization is particularly important for the desertification control in sandy land. Based on land use data of eight periods from 1980 to 2020, we extracted the spatial distribution information of oasis land in Mu Us Sandy Land, and analyzed the spatio-temporal variations of land transformation patterns and stability of oasis land with overlay analysis and grid analysis. The results showed that desertification in the Mu Us Sandy Land had reversed, with a significant process of oasis. The area of forest and grassland increased from 10.2% in 1980 to 73.7% in 2020, while the area of oasisization land increased from 32500 km2 in 1980 to 33900 km2 in 2020. The area of extremely severe, severe, and moderate desertification significantly decreased, while the area of non-desertification and mild desertification obviously increased. The four patterns of oasisization land transformation, including stability, fluctuation, expansion, and retreat, which accounted for 78.7%, 12.2%, 6.2%, and 2.9% of the oasisization land area in 2020, respectively. The oasisization land with low change intensity (the cumulative change intensity less than 0.12) in the Mu Us Sandy Land accounted for 82.7% of the total oasisization area, and the oasisization land in the sandy land was generally stable. Zoning management strategies should be applied according to the stability of sand belt and transformation pattern of oasisization land to achieve the goal of efficient system management and improvement, including eliminating sand hazards at desertification expansion areas with strong wind and sand activities, consolidating sand resources at oasisization areas where ecologically fragile desertification was frequent, and sustainably managing and utilizing sand resources at stable expansion of oases in forest- and grass-rich oasisization areas.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , China , Árvores/crescimento & desenvolvimento , Dióxido de Silício , Florestas , Pradaria , Areia , Poaceae/crescimento & desenvolvimento
2.
Adv Mater ; : e2310080, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38479011

RESUMO

Modifying perovskite surface using various organic ammonium halide cations has proven to be an effective approach for enhancing the overall performance of perovskite solar cells. Nevertheless, the impact of the structural symmetry of these ammonium halide cations on perovskite interface termination has remained uncertain. Here, this work investigates the influence of symmetry on the performance of the devices, using molecules based on symmetrical bis(2-chloroethyl)ammonium cation (B(CE)A+ ) and asymmetrical 2-chloroethylammonium cation (CEA+ ) as interface layers between the perovskite and hole transport layer. These results reveal that the symmetrical B(CE)A+ cations lead to a more homogeneous surface potential and more comprehensive chelation with uncoordinated Pb2+ compared to the asymmetrical cations, resulting in a more favorable energy band alignment and strengthened defect healing. This strategy, leveraging the spatial geometrical symmetry of the interface cations, promotes hole carrier extraction between functional layers and reduces nonradiative recombination on the perovskite surface. Consequently, perovskite solar cells processed with the symmetrical B(CE)A+ cations achieve a power conversion efficiency (PCE) of 25.60% and retain ≈91% of their initial PCE after 500 h of maximum power point operation. This work highlights the significant benefits of utilizing structurally symmetrical cations in promoting the performance and stability of perovskite solar cells.

3.
Biomed Chromatogr ; 38(5): e5846, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38412865

RESUMO

This study investigates the impact of exosomes on bone fracture healing in a rat tibial model, distinguishing between fast and slow healing processes. Bone healing and protein expression were assessed through X-ray examinations, hematoxylin and eosin staining, and immunohistochemical staining. Exosomes were isolated, characterized and subjected to liquid chromatography-mass spectrometry for protein analysis. Molecular differences were explored using differentially expressed protein analysis, Kyoto Encyclopedia of Genes and Genomes pathway enrichment and protein-protein interaction networks. Differential bone healing patterns and protein expressions were observed between the control and model groups. Exosomes were successfully isolated and characterized, revealing 2004 identified proteins, including distinct expression profiles. Notably, ribosomal proteins, ferritin and beta-actin emerged as pivotal players in bone fracture healing. This study unveils dynamic changes in bone healing and underscores the role of exosomes in the process. Identified proteins and pathways offer valuable insights for developing innovative therapeutic strategies for bone healing.


Assuntos
Modelos Animais de Doenças , Exossomos , Consolidação da Fratura , Proteoma , Proteômica , Ratos Sprague-Dawley , Fraturas da Tíbia , Animais , Ratos , Proteômica/métodos , Exossomos/metabolismo , Exossomos/química , Consolidação da Fratura/fisiologia , Fraturas da Tíbia/metabolismo , Proteoma/análise , Proteoma/metabolismo , Masculino , Cromatografia Líquida/métodos , Mapas de Interação de Proteínas
4.
Arab J Gastroenterol ; 25(1): 37-41, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38220480

RESUMO

BACKGROUND AND STUDY AIMS: It has been suggested that the combined detection of multiple serum biomarkers can effectively screen out the high-risk population of chronic atrophic gastritis in the general population. Therefore, it is necessary to establish an effective predictive model of chronic atrophic gastritis. PATIENTS AND METHODS: Serum biopsies were assessed using five stomach-specific circulating biomarkers pepsinogen I (PGI), PGII, PGI/II ratio, anti- H. pylori antibody, and gastrin-17 (G-17) to identify high-risk individuals and evaluate the risk of developing chronic atrophic gastritis. RESULTS: In the cross-sectional analysis, PGII, the PG ratio, G17, anti- H. pylori IgG were positively associated with the presence of chronic atrophic gastritis, and combined prediction of the five biomarkers was more accurate than single-factor prediction ((0.692 vs 0.54(PG1), 0.604 (PGⅡ), 0.616(PGI/II ratio), 0.629(G-17)). CONCLUSION: The combination of PGI, PGII, the PGI/II ratio, G17, and anti-H. pylori antibodies for serological analysis are helpful to screen chronic atrophic gastritis high-risk subjects from the general population and recommend that these people carry out further endoscopy and biopsy.


Assuntos
Gastrite Atrófica , Infecções por Helicobacter , Helicobacter pylori , Humanos , Gastrite Atrófica/diagnóstico , Estudos Transversais , Biomarcadores , Pepsinogênio A , Pepsinogênio C , Anticorpos Antibacterianos , Infecções por Helicobacter/complicações , Infecções por Helicobacter/diagnóstico
5.
Small ; : e2310908, 2024 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-38279585

RESUMO

The high potassization/depotassization energy barriers and lack of efficient ion diffusion pathways are two serious obstacles for carbon-based materials to achieve satisfactory potassium ion storage performance. Herein, a facile and controllable one-step exfoliation-doping-etching strategy is proposed to construct heteroatoms (N, O, and S)-doped mesoporous few-layer carbon nanosheets (NOS-C). The mixed molten salts of KCl/K2 SO4 are innovatively used as the exfoliators, dopants, and etching agents, which enable NOS-C with expanded interlayer spacing and uniformly distributed mesopores with the adjusted electronic structure of surrounding carbon atoms, contributing efficient dual (vertical and horizontal) K-ion diffusion pathways, low potassization/depotassization energy barriers and abundant active sites. Thus, the NOS anodes achieve a high reversible capacity of 516.8 mAh g-1 at 0.05 A g-1 , superior rate capability of 202.8 mAh g-1 at 5 A g-1 and excellent long-term cyclic stability, and their practical application potential is demonstrated by the assembled potassium-ion full batteries. Moreover, a surface-interlayer synergetic K+ storage mechanism is revealed by a combined theoretical and experimental approach including in situ EIS, in situ Raman, ex situ XPS, and SEM analysis. The proposed K+ storage mechanism and unique structural engineering provide a new pathway for potassium-ion storage devices and even beyond.

6.
Nat Commun ; 14(1): 6831, 2023 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-37884521

RESUMO

The middle ear ossicles in modern mammals are repurposed from postdentary bones in non-mammalian cynodonts. Recent discoveries by palaeontological and embryonic studies have developed different models for the middle ear evolution in mammaliaforms. However, little is known about the evolutionary scenario of the middle ear in early therians. Here we report a detached middle ear preserved in a new eutherian mammal from the Early Cretaceous Jehol Biota. The well-preserved articulation of the malleus and incus suggest that the saddle-shaped incudomallear joint is a major apomorphy of Early Cretaceous eutherians. By contrast to the distinct saddle-like incudomallear articulation in therians, differences between the overlapping versus the half-overlapping incudomallear joints in monotremes and stem mammals would be relatively minor. The middle ear belongs to the microtype by definition, indicating its adaptation to high-frequency hearing. Current evidence indicates that significant evolutionary innovations of the middle ear in modern therians evolved in Early Cretaceous.


Assuntos
Evolução Biológica , Eutérios , Animais , Filogenia , Mamíferos , Orelha Média , Fósseis
7.
Regen Ther ; 24: 103-111, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37384240

RESUMO

The skin, being the largest organ in the human body, plays a vital role in shielding internal organs from external physical and chemical factors. However, skin damage caused by various factors such as injuries, surgeries, diabetes, or burns can lead to wounds that diminish the skin's protective function. Monitoring essential physiological parameters like temperature, moisture, and pH is crucial to facilitate antibiotic treatment, remote physician monitoring, patient comfort, cost reduction, and prevention of hospital-acquired infections. To this end, innovative wound coverings made of biological materials like gelatin, carboxymethyl chitosan, and titanium nanoparticles have been developed, mainly for hospital and pediatric applications. These wound coverings come equipped with sensors to monitor temperature, pH, and moisture and are suitable for pediatric hospitals where children experience difficulty in wound healing due to their sensitive skin. The temperature monitoring feature allows physicians to accurately assess the wound's temperature, detect potential infections, and take prompt actions. These wound coverings can significantly enhance wound treatment for patients, as real-time monitoring of physiological parameters enables informed decision-making by physicians, leading to better therapeutic outcomes. Furthermore, the use of these wound coverings can minimize the risk of hospital-acquired infections. Their adaptability and flexibility make them ideal for various wound types and sizes, ensuring patient comfort and compliance with the treatment plan. In conclusion, the development of innovative and flexible wound coverings using biological materials and equipped with sensors represents a significant breakthrough in wound management. The use of these wound coverings has the potential to revolutionize wound care and improve patient outcomes, particularly in pediatric hospitals where wound healing is often challenging.

8.
Front Neurosci ; 17: 1141701, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36968504

RESUMO

Spiking neural networks (SNNs) have attracted intensive attention due to the efficient event-driven computing paradigm. Among SNN training methods, the ANN-to-SNN conversion is usually regarded to achieve state-of-the-art recognition accuracies. However, many existing ANN-to-SNN techniques impose lengthy post-conversion steps like threshold balancing and weight renormalization, to compensate for the inherent behavioral discrepancy between artificial and spiking neurons. In addition, they require a long temporal window to encode and process as many spikes as possible to better approximate the real-valued ANN neurons, leading to a high inference latency. To overcome these challenges, we propose a calcium-gated bipolar leaky integrate and fire (Ca-LIF) spiking neuron model to better approximate the functions of the ReLU neurons widely adopted in ANNs. We also propose a quantization-aware training (QAT)-based framework leveraging an off-the-shelf QAT toolkit for easy ANN-to-SNN conversion, which directly exports the learned ANN weights to SNNs requiring no post-conversion processing. We benchmarked our method on typical deep network structures with varying time-step lengths from 8 to 128. Compared to other research, our converted SNNs reported competitively high-accuracy performance, while enjoying relatively short inference time steps.

9.
Adv Mater ; 35(23): e2210186, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36961356

RESUMO

Sequential deposition has been widely employed to modulate the crystallization of perovskite solar cells because it can avoid the formation of nucleation centers and even initial crystallization in the precursor solution. However, challenges remain in overcoming the incomplete and random transformation of PbI2 films with organic ammonium salts. Herein, a unique intermediate phase engineering strategy has been developed by simultaneously introducing 2,2-azodi(2-methylbutyronitrile) (AMBN) to both PbI2 and ammonium salt solutions to regulate perovskite crystallization. AMBN not only coordinates with PbI2 to form a favorably mesoporous PbI2 film due to the coordination between Pb2+ and the cyano group (C≡N), but also suppresses the vigorous activity of FA+ ions by interacting with FAI, leading to the full PbI2 transformation with the preferred orientation. Therefore, perovskites with favorable facet orientations are obtained, and the defects are largely suppressed owing to the passivation of uncoordinated Pb2+ and FA+ . As a result, a champion power conversion efficiency over 25% with a stabilized efficiency of 24.8% is achieved. Moreover, the device exhibits an improved operational stability, retaining 96% of initial power conversion efficiency under 1000 h continuous white-light illumination with an intensity of 100 mW cm-2 at ≈55 °C in N2 atmosphere.

10.
Biomed Pharmacother ; 154: 113628, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36058145

RESUMO

Immunoglobulin protein CD47 is overexpressed in malignant tumor cells, allowing them to evade host immunity mainly by inhibiting macrophage-mediated phagocytosis. Taxus chinensis var. mairei (TC) exhibits high antitumor efficacy with low toxicity and notable cost-effectiveness. However, it is unknown whether aqueous extract of TC (AETC) is an immunomodulator that mediates antitumor efficacy. In this study, we aimed to elucidate the critical role of CD47 degradation in the treatment of AETC in non-small cell lung cancer (NSCLC) cells. A mouse Lewis lung carcinoma model was developed to determine whether the administration of AETC, as an anti-CD47 antibody, in combination with anti-PD-1 could synergistically inhibit tumor growth and promote a peripheral immune response. AETC treatment downregulated CD47 levels in NSCLC cells and Lewis tumor xenograft mice. Furthermore, treatment enhanced immunity against NSCLC by triggering CD47 ubiquitination and degradation, promoting macrophage-mediated tumor cell phagocytosis, and activating CD8+ T cells. The present study empirically demonstrated, for the first time, that AETC exerts antitumor properties as an immunomodulator. Our findings present AETC as a promising alternative or adjuvant treatment in lung cancer therapy.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Taxus , Animais , Antígeno CD47 , Linfócitos T CD8-Positivos/metabolismo , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Xenoenxertos , Humanos , Neoplasias Pulmonares/patologia , Camundongos
11.
Genes Dis ; 9(6): 1757-1758, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36157500

RESUMO

[This corrects the article DOI: 10.1016/j.gendis.2020.07.005.][This corrects the article DOI: 10.1016/j.gendis.2021.09.001.].

12.
Artigo em Inglês | MEDLINE | ID: mdl-35954892

RESUMO

Wind erosion is crucial for assessing regional ecosystem services and sustainable development. The Agro-Pastoral Ecotone of northern China (APEC) is a typical region undergoing wind erosion and soil degradation. In this study, the National Wind Erosion Survey Model of China, the Integrated Wind Erosion Modeling System, and the regional versions of the Revised Wind Erosion Equation and Wind Erosion Prediction System were used to evaluate the regional potential wind erosion of the APEC during 2000 and 2012. The results showed that the potential wind erosion predicted by National Wind Erosion Survey Model of China (NWESMC), Revised Wind Erosion Equation (RWEQ), Wind Erosion Prediction System (WEPS), and Integrated Wind Erosion Modeling System (IWEMS) were significantly related to the observed wind erosion collected from published literature, but the observed data were generally smaller than the predicted values. The average potential wind erosions were 12.58, 25.87, 52.63, and 58.72 t hm-2 a-1 for NWESMC, RWEQ, WEPS, and IWEMS, respectively, while the spatial pattern and temporal trend of annual potential wind erosion were similar for different wind erosion models. Wind speed, soil moisture, and vegetation coverage were the dominant factors affecting regional wind erosion estimation. These results highlight that it is necessary to comprehensively calibrate and validate the selected wind erosion models. A long-term standard wind erosion monitoring network is urgently required. This study can serve as a useful reference for improving wind erosion models.


Assuntos
Ecossistema , Vento , China , Conservação dos Recursos Naturais , Solo
13.
IEEE Trans Biomed Circuits Syst ; 16(4): 636-650, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35802542

RESUMO

Human brain cortex acts as a rich inspiration source for constructing efficient artificial cognitive systems. In this paper, we investigate to incorporate multiple brain-inspired computing paradigms for compact, fast and high-accuracy neuromorphic hardware implementation. We propose the TripleBrain hardware core that tightly combines three common brain-inspired factors: the spike-based processing and plasticity, the self-organizing map (SOM) mechanism and the reinforcement learning scheme, to improve object recognition accuracy and processing throughput, while keeping low resource costs. The proposed hardware core is fully event-driven to mitigate unnecessary operations, and enables various on-chip learning rules (including the proposed SOM-STDP & R-STDP rule and the R-SOM-STDP rule regarded as the two variants of our TripleBrain learning rule) with different accuracy-latency tradeoffs to satisfy user requirements. An FPGA prototype of the neuromorphic core was implemented and elaborately tested. It realized high-speed learning (1349 frame/s) and inference (2698 frame/s), and obtained comparably high recognition accuracies of 95.10%, 80.89%, 100%, 94.94%, 82.32%, 100% and 97.93% on the MNIST, ETH-80, ORL-10, Yale-10, N-MNIST, Poker-DVS and Posture-DVS datasets, respectively, while only consuming 4146 (7.59%) slices, 32 (3.56%) DSPs and 131 (24.04%) Block RAMs on a Xilinx Zynq-7045 FPGA chip. Our neuromorphic core is very attractive for real-time resource-limited edge intelligent systems.


Assuntos
Redes Neurais de Computação , Plasticidade Neuronal , Algoritmos , Computadores , Humanos , Neurônios
14.
Genes Dis ; 9(2): 443-455, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35224159

RESUMO

Podocyte injury is an important cause of proteinuria. Angiopoietin-like protein 4 (Angptl4) is a secreted glycoprotein and has a role in proteinuria. However, the exact role of Angptl4 in podocyte injury and its upstream regulators has not been clarified. In this study, we used lipopolysaccharide (LPS)-induced mice and cultured podocytes as podocyte injury models. Our results indicated that LPS increased the expression of podocyte Angptl4 in vivo and in vitro. Furthermore, we showed that Angptl4 overexpression deteriorated LPS-induced podocyte injury by inducing podocyte cytoskeleton rearrangement, reducing the expression of synaptopodin while Angptl4 knockdown alleviated LPS-induced podocyte injury. In addition, we found that inhibitors and siRNA targeting TLR4/MyD88/NF-κB signaling inhibited the upregulation of Angptl4 in LPS-induced podocytes. Moreover, inhibitors and siRNA targeting calcineurin/NFAT signaling also relieved LPS-induced Angptl4 expression and podocyte injury in vivo and in vitro. Taken together, our study has elucidated that both of the TLR4/MyD88/NF-κB and calcineurin/NFAT signaling mediate the upregulation of Angptl4 in LPS-induced podocytes, which has important implications for further understanding the molecular mechanism of LPS-induced podocyte injury.

15.
Philos Trans R Soc Lond B Biol Sci ; 377(1847): 20210042, 2022 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-35125007

RESUMO

Here we report on a new Early Cretaceous eutherian represented by a partial skeleton from the Jiufotang Formation at Sihedang site, Lingyuan City, Liaoning Province that fills a crucial gap between the earliest eutherians from the Yixian Formation and later Cretaceous eutherians. The new specimen reveals, to our knowledge for the first time in eutherians, that the Meckelian cartilage was ossified but reduced in size, confirming a complete detachment of the middle ear from the lower jaw. Seven hyoid elements, including paired stylohyals, epihyals and thyrohyals and the single basihyal are preserved. For the inner ear the ossified primary lamina, base of the secondary lamina, ossified cochlear ganglion and secondary crus commune are present and the cochlear canal is coiled through 360°. In addition, plesiomorphic features of the dentition include weak conules, lack of pre- and post-cingula and less expanded protocones on the upper molars and height differential between the trigonid and talonid, a large protoconid and a small paraconid on the lower molars. The new taxon displays an alternating pattern of tooth replacement with P3 being the last upper premolar to erupt similar to the basal eutherian Juramaia. Parsimony analysis places the new taxon with Montanalestes, Sinodelphys and Ambolestes as a sister group to other eutherians. This article is part of the theme issue 'The impact of Chinese palaeontology on evolutionary research'.


Assuntos
Eutérios , Fósseis , Animais , Biota , Mamíferos , Filogenia
17.
Ecol Evol ; 11(17): 11689-11699, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34522333

RESUMO

The construction of morphological character matrices is central to paleontological systematic study, which extracts paleontological information from fossils. Although the word information has been repeatedly mentioned in a wide array of paleontological systematic studies, its meaning has rarely been clarified nor specifically defined. It is important, however, to establish a standard to measure paleontological information because fossils are hardly complete, rendering the recognition of homologous and homoplastic structures difficult. Here, based on information theory, we show the deep connections between paleontological systematic study and communication system engineering. Information is defined as the decrease of uncertainty and it is the information in morphological characters that allows distinguishing operational taxonomic units (OTUs) and reconstructing evolutionary history. We propose that concepts in communication system engineering such as source coding and channel coding, correspond to the construction of diagnostic features and the entire character matrices in paleontological studies. The two coding strategies should be distinguished following typical communication system engineering, because they serve dual purposes. With character matrices from six different vertebrate groups, we analyzed their information properties including source entropy, mutual information, and channel capacity. Estimation of channel capacity shows character saturation of all matrices in transmitting paleontological information, indicating that, due to the presence of noise, oversampling characters not only increases the burden in character scoring, but also may decrease quality of matrices. We further test the use of information entropy, which measures how informative a variable is, as a character weighting criterion in parsimony-based systematic studies. The results show high consistency with existing knowledge with both good resolution and interpretability.

18.
Cell Death Dis ; 12(2): 186, 2021 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-33589596

RESUMO

Chemotherapy drug-induced nephrotoxicity limits clinical applications for treating cancers. Pyroptosis, a newly discovered programmed cell death, was recently reported to be associated with kidney diseases. However, the role of pyroptosis in chemotherapeutic drug-induced nephrotoxicity has not been fully clarified. Herein, we demonstrate that the chemotherapeutic drug cisplatin or doxorubicin, induces the cleavage of gasdermin E (GSDME) in cultured human renal tubular epithelial cells, in a time- and concentration-dependent manner. Morphologically, cisplatin- or doxorubicin-treated renal tubular epithelial cells exhibit large bubbles emerging from the cell membrane. Furthermore, activation of caspase 3, not caspase 9, is associated with GSDME cleavage in cisplatin- or doxorubicin-treated renal tubular epithelial cells. Meanwhile, silencing GSDME alleviates cisplatin- or doxorubicin-induced HK-2 cell pyroptosis by increasing cell viability and decreasing LDH release. In addition, treatment with Ac-DMLD-CMK, a polypeptide targeting mouse caspase 3-Gsdme signaling, inhibits caspase 3 and Gsdme activation, alleviates the deterioration of kidney function, attenuates renal tubular epithelial cell injury, and reduces inflammatory cytokine secretion in vivo. Specifically, GSDME cleavage depends on ERK and JNK signaling. NAC, a reactive oxygen species (ROS) inhibitor, reduces GSDME cleavage through JNK signaling in human renal tubular epithelial cells. Thus, we speculate that renal tubular epithelial cell pyroptosis induced by chemotherapy drugs is mediated by ROS-JNK-caspase 3-GSDME signaling, implying that therapies targeting GSDME may prove efficacious in overcoming chemotherapeutic drug-induced nephrotoxicity.


Assuntos
Caspase 3/metabolismo , Cisplatino/efeitos adversos , Doxorrubicina/efeitos adversos , Nefropatias/induzido quimicamente , Receptores de Estrogênio/metabolismo , Animais , Linhagem Celular , Linhagem Celular Tumoral , Cisplatino/farmacologia , Doxorrubicina/farmacologia , Células Epiteliais/efeitos dos fármacos , Humanos , Nefropatias/metabolismo , Nefropatias/patologia , Túbulos Renais/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Piroptose/efeitos dos fármacos , Distribuição Aleatória
19.
Adv Mater ; 33(3): e2007126, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33296122

RESUMO

So far, the combination of methylammonium bromide/methylammonium chloride (MABr/MACl) or methylammonium iodide (MAI)/MACl is the most frequently used additives to stabilize formamidinium lead iodide (FAPbI3 ) fabricated by the sequential deposition method. However, the enlarged bandgap due to the addition of bromide and the ambiguous functions of these additives in lead iodide (PbI2 ) transformation are still worth considering. Herein, the roles of MACl in sequentially deposited Br-free FA-based perovskites are systematically investigated. It is found that MACl can finely regulate the PbI2 /FAI reaction, tune the phase transition at room temperature, and adjust intermediate-related perovskite crystallization and decomposition during thermal annealing. Compared to FAPbI3 , the perovskite with MACl exhibits larger grain, longer carrier lifetime, and reduced trap density. The resultant solar cell therefore achieves a champion power conversion efficiency (PCE) of 23.1% under reverse scan with a stabilized power output of 23.0%. In addition, it shows much improved photostability under 100 mW cm-2 white illumination (xenon lamp) in nitrogen atmosphere without encapsulation.

20.
ACS Appl Mater Interfaces ; 12(43): 48458-48466, 2020 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-33073991

RESUMO

Wide-band gap (WBG) mixed-halide perovskites have drawn much attention because of their excellent optoelectronic properties and the potential to be deployed in tandem solar cells. Nevertheless, the bromine incorporation inevitably leads to photoinduced phase segregation in WBG mixed-halide perovskites. Herein, potassium is used to effectively suppress photoinduced phase segregation, which is visualized with confocal photoluminescence microscopy imaging. Strikingly, the potassium passivation not only inhibits the formation of the narrow-band gap subphase but also enhances the crystallinity of the WBG mixed-halide perovskite. In addition, the potassium-passivated WBG perovskite exhibits lower defect density, longer charge carrier lifetime, and better photostability. As a result, the optimized KI (2 mol %)-passivated WBG perovskite solar cells (PSCs) deliver a champion power conversion efficiency of 18.3% with negligible hysteresis. They maintain 98% of their initial efficiency after 400 h under 100 mW·cm-2 white light illumination in nitrogen.

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