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1.
Adv Sci (Weinh) ; 11(9): e2305861, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38111327

RESUMO

Anomalous thermal transport of Cs2 NaYbCl6 double-halide perovskite above room temperature is reported and rationalized. Calculations of phonon dispersion relations and scattering rates up to the fourth order in lattice anharmonicity have been conducted to determine their effective dependence on temperature. These findings show that specific phonon group velocities and lifetimes increase if the temperature is raised above 500 K. This, in combination with anharmonicity, provides the microscopic mechanism responsible for the increase in lattice thermal conductivity at high temperatures, contrary to the predictions of phonon transport theories based on solely cubic anharmonicity. The model accurately and quantitatively reproduces the experimental thermal conductivity data as a function of temperature.

2.
Funct Integr Genomics ; 23(3): 225, 2023 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-37418046

RESUMO

Y box binding protein 3 (YBX3) is an indispensable factor for protein synthesis, cellular growth, and proliferation, and is intricately involved in the progression of diverse tumor types. The objective of the current study was to investigate the role of YBX3 in the prognosis, immune infiltration, and progression of clear cell renal clear cell carcinoma (ccRCC). The expression level of YBX3 in ccRCC tissues was compared using The Cancer Genome Atlas (TCGA) and analyzed using the Wilcoxon rank sum test. Logistic regression and multivariate Cox analyses were subsequently employed to scrutinize the association between YBX3 expression and the clinicopathological characteristics of patients. The TIMER 2.0 tool was also utilized to quantify the degree of immune cell infiltration of YBX3. Kaplan Meier analysis was performed to assess the correlation between YBX3 and the survival rate. A high expression level of YBX3 was significantly correlated with the tumor pathological stage, histological grade, TNM stage, and the abundance of aDC, pDC, Th1, and Treg immune cells. Higher expression of YBX3 in advanced ccRCC was found to be associated with a lower overall survival rate in the M0, N0, and T2 subgroups. In vitro, after the silencing of YBX3 in A498 cells and overexpression of YBX3 in ACHN cells, cell proliferation, colony formation, migration, invasion, cell cycle assays, and flow cytometric apoptotic analysis were performed to evaluate the role of YBX3 in the progression of ccRCC. YBX3 was found to be intricately associated with the progression and prognosis of ccRCC, and may serve as an effective treatment target for ccRCC or a biomarker for prognosis prediction.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Humanos , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/metabolismo , Carcinoma de Células Renais/patologia , Estimativa de Kaplan-Meier , Neoplasias Renais/genética , Neoplasias Renais/metabolismo , Neoplasias Renais/patologia , Oncogenes , Proteínas de Ligação a RNA/genética
3.
Animals (Basel) ; 13(10)2023 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-37238144

RESUMO

To protect birds, it is crucial to identify their species and determine their population across different regions. However, currently, bird monitoring methods mainly rely on manual techniques, such as point counts conducted by researchers and ornithologists in the field. This method can sometimes be inefficient, prone to errors, and have limitations, which may not always be conducive to bird conservation efforts. In this paper, we propose an efficient method for wetland bird monitoring based on object detection and multi-object tracking networks. First, we construct a manually annotated dataset for bird species detection, annotating the entire body and head of each bird separately, comprising 3737 bird images. We also built a new dataset containing 11,139 complete, individual bird images for the multi-object tracking task. Second, we perform comparative experiments using a state-of-the-art batch of object detection networks, and the results demonstrated that the YOLOv7 network, trained with a dataset labeling the entire body of the bird, was the most effective method. To enhance YOLOv7 performance, we added three GAM modules on the head side of the YOLOv7 to minimize information diffusion and amplify global interaction representations and utilized Alpha-IoU loss to achieve more accurate bounding box regression. The experimental results revealed that the improved method offers greater accuracy, with mAP@0.5 improving to 0.951 and mAP@0.5:0.95 improving to 0.815. Then, we send the detection information to DeepSORT for bird tracking and classification counting. Finally, we use the area counting method to count according to the species of birds to obtain information about flock distribution. The method described in this paper effectively addresses the monitoring challenges in bird conservation.

4.
Nat Chem Biol ; 19(8): 940-950, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37055614

RESUMO

Microbial communities often display region-specific properties, which give rise to complex interactions and emergent behaviors that are critical to the homeostasis and stress response of the communities. However, systems-level understanding of these properties still remains elusive. In this study, we established RAINBOW-seq and profiled the transcriptome of Escherichia coli biofilm communities with high spatial resolution and high gene coverage. We uncovered three modes of community-level coordination, including cross-regional resource allocation, local cycling and feedback signaling, which were mediated by strengthened transmembrane transport and spatially specific activation of metabolism. As a consequence of such coordination, the nutrient-limited region of the community maintained an unexpectedly high level of metabolism, enabling it to express many signaling genes and functionally unknown genes with potential sociality functions. Our work provides an extended understanding of the metabolic interplay in biofilms and presents a new approach of investigating complex interactions in bacterial communities on the systems level.


Assuntos
Escherichia coli K12 , Escherichia coli K12/genética , Escherichia coli/genética , Transcriptoma , Biofilmes , Bactérias/genética
5.
Sensors (Basel) ; 23(4)2023 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-36850614

RESUMO

Perovskite CsPbBr3 semiconductors exhibit unusually high defect tolerance leading to outstanding and unique optoelectronic properties, demonstrating strong potential for γ-radiation and X-ray detection at room temperature. However, the total dose effects of the perovskite CsPbBr3 must be considered when working in a long-term radiation environment. In this work, the Schottky type of perovskite CsPbBr3 detector was fabricated. Their electrical characteristics and γ-ray response were investigated before and after 60Co γ ray irradiation with 100 and 200 krad (Si) doses. The γ-ray response of the Schottky-type planar CsPbBr3 detector degrades significantly with the increase in total dose. At the total dose of 200 krad(Si), the spectral resolving ability to γ-ray response of the CsPbBr3 detector has disappeared. However, with annealing at room temperature for one week, the device's performance was partially recovered. Therefore, these results indicate that the total dose effects strongly influence the detector performance of the perovskite CsPbBr3 semiconductor. Notably, it is concluded that the radiation-induced defects are not permanent, which could be mitigated even at room temperature. We believe this work could guide the development of perovskite detectors, especially under harsh radiation conditions.

6.
Environ Microbiol ; 24(12): 5774-5787, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36053758

RESUMO

There is a lack of appropriate methods for preparing bacterial RNA-seq library with ultra-low amount of RNA. To address this issue, we developed miniBac-seq, a strand-specific method for high-quality library construction from sub-nanogram of total RNA, which is 100-fold lower than the current benchmark kit and dramatically reduces preparation cost ($28 + $15 × samples). We further demonstrated the high sensitivity of miniBac-seq via detecting more than 500 genes from amount of total RNA equivalent to that of a single bacterial cell. Finally, we profiled the transcriptome of growth-arrested bacteria in isogenic culture of Escherichia coli. This subpopulation of bacteria is generally low in abundance but is a potent reservoir of antibiotic persistence, and their gene expression has been largely unknown due to technical limitations. Using miniBac-seq, we identified potential molecular driver towards arrested growth as well as antibiotic tolerance. Our method thus expands the capacity to quantify bacterial transcriptome in situ, which is useful to the understanding of bacterial physiology and regulation in their native contexts.


Assuntos
Perfilação da Expressão Gênica , Transcriptoma , Análise de Sequência de RNA/métodos , Perfilação da Expressão Gênica/métodos , RNA , Bactérias/genética , Antibacterianos/farmacologia , Sequenciamento de Nucleotídeos em Larga Escala/métodos
7.
IEEE Trans Med Imaging ; 41(11): 3053-3061, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35594210

RESUMO

X-ray photon-counting detectors capable of resolving the energies of single X-ray photons are critical in medical imaging, and a high count rate is essential for photon-counting detectors. Here, we report the performance of the perovskite CsPbBr3 single-crystal semiconductor detector for X-ray photon counting. The CsPbBr3 detector noise floor, energy response linearity, energy resolution, count rate, and polarization were evaluated. By fine-tuning the detector working conditions, our CsPbBr3 detector with a planar electrode can count an incident X-ray photon rate of ~0.099 and ~0.336 Mcps/pixel at 10% and 30% deadtime loss, respectively, with corresponding energy resolutions of ~18% at 59.5 keV and ~12% at 122 keV at same pulse processing conditions. We also demonstrated that our CsPbBr3 detectors show negligible polarization under an X-ray flux of ~0.45 M photons/s/mm2 for the typical timescale of multiple clinical X-ray scans, such as 1 s- 100 s. Our evaluation demonstrates the high potential of CsPbBr3 detectors for X-ray photon-counting applications in medical and industrial diagnostics with a lower cost than the current state-of-the-art.


Assuntos
Fótons , Raios X , Radiografia
8.
Ann Clin Lab Sci ; 52(2): 230-239, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35414502

RESUMO

OBJECTIVE: Thymosin b10 (TMSB10), a member of the thymosin family, is mainly located in cells and participates in the assembly and occurrence of cytoskeleton. We aimed to investigate the regulatory mechanism of TMSB10 in ccRCC. METHODS: In this study, Xiantao Academic Tools were taken to perform the pan-cancer expression and immune infiltration analysis of TMSB10. Furthermore, it is found that there is a binding site for JUN in the promoter region of TMSB10 through the JASPAR database predictive analysis. The CHIP experiment is used to confirm that JUN regulates the expression of TMSB10 through transcription, and to further detect the mRNA expression level of TMSB10 and JUN in ccRCC cell lines by qRT-PCR. Proliferation and apoptosis function analysis was also carried out to determine the functional changes of ccRCC cell lines after the expression of TMSB10 was regulated by JUN transcription. RESULTS: The results show that TMSB10 is significantly up-regulated in a variety of cancers. Moreover, JUN regulates the high expression of TMSB10 through transcription and further promotes the proliferation of ccRCC cells and inhibits their apoptosis. CONCLUSIONS: In conclusion, this study shows that JUN transcription regulates the high expression of TMSB10 and promotes the progress of ccRCC.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Timosina , Apoptose/genética , Carcinoma de Células Renais/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Renais/genética , Prognóstico , Timosina/genética , Timosina/metabolismo , Timosina/farmacologia
9.
IEEE Trans Radiat Plasma Med Sci ; 6(7): 804-810, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37008042

RESUMO

Semiconductor-based radiation detectors can typically achieve better energy and spatial resolution when compared to scintillator-based detectors. However, if used for positron emission tomography (PET), semiconductor-based detectors normally cannot achieve excellent coincidence time resolution (CTR), due to the relatively slow charge carrier collection time limited by the carrier drift velocity. If we can collect prompt photons emitted from certain semiconductor materials, there are possibilities that the CTR can be greatly improved, and time-of-flight (ToF) capability can be achieved. In this paper, we studied the prompt photon emission (mainly Cherenkov luminescence) property and fast timing capability of cesium lead chloride (CsPbCl3) and cesium lead bromide (CsPbBr3), which are two new perovskite semiconductor materials. We also compared their performance with thallium bromide (TlBr), another semiconductor material that has already been studied for timing using its Cherenkov emissions. We performed coincidence measurements using silicon photomultipliers (SiPMs), and the full-width-at-half-maximum (FWHM) CTR acquired between a semiconductor sample crystal and a reference lutetium-yttrium oxyorthosilicate (LYSO) crystal (both with dimensions of 3 × 3 × 3 mm3) is 248 ± 8 ps for CsPbCl3, 440 ± 31 ps for CsPbBr3, and 343 ± 16 ps for TlBr. Deconvolving the contribution to CTR from the reference LYSO crystal (around 100 ps) and then multiplying by the square root of 2, the estimated CTR between two of the same semiconductor crystals was calculated as 324 ± 10 ps for CsPbCl3, 606 ± 43 ps for CsPbBr3 and 464 ± 22 ps for TlBr. This ToF capable CTR performance combined with an easily scalable crystal growth process, low cost and toxicity, as well as good energy resolution lead us to the conclusion that new perovskite materials such as CsPbCl3 and CsPbBr3 could be excellent candidates as PET detector materials.

10.
J Am Chem Soc ; 143(16): 6221-6228, 2021 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-33856803

RESUMO

Chalcogenide-based phase change memory (PCM) is a key enabling technology for optical data storage and electrical nonvolatile memory. Here, we report a new phase change chalcogenide consisting of a 3D network of ionic (K···Se) and covalent bonds (Bi-Se), K2Bi8Se13 (KBS). Thin films of amorphous KBS deposited by DC sputtering are structurally and chemically homogeneous and exhibit a surface roughness of 5 nm. The KBS film crystallizes upon heating at ∼483 K. The optical bandgap of the amorphous film is about 1.25 eV, while its crystalline phase has a bandgap of ∼0.65 eV shows 2-fold difference between the two states. The bulk electrical conductivity of the amorphous and crystalline film is ∼7.5 × 10-4 and ∼2.7 × 10-2 S/cm, respectively. We have demonstrated a phase change memory effect in KBS by Joule heating in a technologically relevant vertical memory cell architecture. Upon Joule heating, the vertical device undergoes switching from its amorphous to crystalline state of KBS at 1-1.5 V (∼50 kV/cm), increasing conductivity by a factor of ∼40. Besides the large electrical and optical contrast in the crystalline and amorphous KBS, its elemental cost-effectiveness, stoichiometry, fast crystallization kinetics, as determined by the ratio of the glass transition and melting temperature, Tg/Tm ∼ 0.5, as well as the scalable synthesis of the thin film determine that KBS is a promising PC material for next general phase change memory.

11.
Open Med (Wars) ; 16(1): 224-236, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33585699

RESUMO

BACKGROUND: Previous work has shown that miR-142-5p in cervical cancer tissues increased significantly compared with adjacent normal tissues. However, the function and the mechanism of miR-142-5p in cervical cancer have not been reported. METHODS: Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was used to determine the gene expression levels. MTT, flow cytometry, and transwell assays were performed to explore the functions of miR-142-5p in HeLa cells. The potential target gene of miR-142-5p was investigated via luciferase reporter assays. The protein expression levels were analyzed by Western blotting. RESULTS: We found that miR-142-5p expression was elevated but LIM homeobox transcription factor 1 alpha (LMX1A) was decreased in cervical cancer tissues and cells. Overexpression of miR-142-5p or knockdown of LMX1A inhibited cell apoptosis, promoted cell proliferation, migration, invasion abilities, and activated the Wnt/ß-catenin pathway. However, knockdown of miR-142-5p or overexpression of LMX1A showed opposite results. LMX1A was identified as a direct target of miR-142-5p by luciferase reporter assays. Finally, rescue experiments demonstrated that LMX1A overexpression attenuated the carcinogenic effect of miR-142-5p mimic on HeLa cells. CONCLUSIONS: These findings suggested that miR-142-5p might be a cervical cancer oncogene and could serve as a potential therapeutic target for the treatment of cervical cancer.

12.
Adv Mater ; 33(8): e2006010, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33475209

RESUMO

Low ionic migration is required for a semiconductor material to realize stable high-performance X-ray detection. In this work, successful controlled incorporation of not only methylammonium (MA+ ) and cesium (Cs+ ) cations, but also bromine (Br- ) anions into the FAPbI3 lattice to grow inch-sized stable perovskite single crystal (FAMACs SC) is reported. The smaller cations and anions, comparing to the original FA+ and I- help release lattice stress so that the FAMACs SC shows lower ion migration, enhanced hardness, lower trap density, longer carrier lifetime and diffusion length, higher charge mobility and thermal stability, and better uniformity. Therefore, X-ray detectors made of the superior FAMACs SCs show the highest sensitivity of (3.5 ± 0.2) × 106 µC Gyair -1 cm-2 , about 29 times higher than the latest record of 1.22 × 105 µC Gyair -1 cm-2 for polycrystalline MAPbI3 wafer under the same 40 keV X-ray radiation. Furthermore, the FAMACs SC X-ray detector shows a low detection limit of 42 nGy s-1 , stable dark current, and photocurrent response. Finally, it is demonstrated that high contrast X-ray imaging is realized using the FAMACs SC detector. The effective triple-cation mixed halide strategy and the high crystalline quality make the present FAMACs SCs promising for next-generation X-ray imaging systems.

13.
J Am Chem Soc ; 143(6): 2545-2551, 2021 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-33465309

RESUMO

Pressure processing is efficient to regulate the structural and physical properties of two-dimensional (2D) halide perovskites which have been emerging for advanced photovoltaic and light-emitting applications. Increasing numbers of studies have reported pressure-induced and/or enhanced emission properties in the 2D halide perovskites. However, no research has focused on their photoresponse properties under pressure tuning. It is also unclear how structural change affects their excitonic features, which govern the optoelectronic properties of the halide perovskites. Herein, we report significantly enhanced photocurrents in the all-inorganic 2D perovskite Cs2PbI2Cl2, achieving over 3 orders of magnitude increase at the industrially achievable level of 2 GPa in comparison with its initial photocurrent. Lattice compression effectively regulates the excitonic features of Cs2PbI2Cl2, reducing the exciton binding energy considerably from 133 meV at ambient conditions to 78 meV at 2.1 GPa. Impressively, such a reduced exciton binding energy of 2D Cs2PbI2Cl2 is comparable to the values of typical 3D perovskites (MAPbBr3 and MAPbI3), facilitating the dissociating of excitons into free carriers and enhancing the photocurrent. Further pressurization leads to a layer-sliding-induced phase transition and an anomalous negative linear compression, which has not been observed so far in other halide perovskites. Our findings reveal the dramatically enhanced photocurrents in the 2D halide perovskite by regulating its excitonic features and, more broadly, provide new insights into materials design toward extraordinary properties.

14.
J Am Chem Soc ; 143(4): 2068-2077, 2021 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-33492148

RESUMO

The detection of γ-rays at room temperature with high-energy resolution using semiconductors is one of the most challenging applications. The presence of even the smallest amount of defects is sufficient to kill the signal generated from γ-rays which makes the availability of semiconductors detectors a rarity. Lead halide perovskite semiconductors exhibit unusually high defect tolerance leading to outstanding and unique optoelectronic properties and are poised to strongly impact applications in photoelectric conversion/detection. Here we demonstrate for the first time that large size single crystals of the all-inorganic perovskite CsPbCl3 semiconductor can function as a high-performance detector for γ-ray nuclear radiation at room temperature. CsPbCl3 is a wide-gap semiconductor with a bandgap of 3.03 eV and possesses a high effective atomic number of 69.8. We identified the two distinct phase transitions in CsPbCl3, from cubic (Pm-3m) to tetragonal (P4/mbm) at 325 K and finally to orthorhombic (Pbnm) at 316 K. Despite crystal twinning induced by phase transitions, CsPbCl3 crystals in detector grade can be obtained with high electrical resistivity of ∼1.7 × 109 Ω·cm. The crystals were grown from the melt with volume over several cubic centimeters and have a low thermal conductivity of 0.6 W m-1 K-1. The mobilities for electron and hole carriers were determined to ∼30 cm2/(V s). Using photoemission yield spectroscopy in air (PYSA), we determined the valence band maximum at 5.66 ± 0.05 eV. Under γ-ray exposure, our Schottky-type planar CsPbCl3 detector achieved an excellent energy resolution (∼16% at 122 keV) accompanied by a high figure-of-merit hole mobility-lifetime product (3.2 × 10-4 cm2/V) and a long hole lifetime (16 µs). The results demonstrate considerable defect tolerance of CsPbCl3 and suggest its strong potential for γ-radiation and X-ray detection at room temperature and above.

15.
Exp Cell Res ; 397(1): 112335, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-33132134

RESUMO

PURPOSE: Skp2, an oncoprotein, regulates tumor proliferation, invasion and metastasis. Ku70 is a critical component of the non-homologous end-joining (NHEJ) process. Both Skp2 and Ku70 are positively associated in multiple cancers. However, there is no report about the relationship between Skp2 and Ku70 proteins. METHODS: In this study, we carried out Bioinformatics and molecular biological methods to investigate the relationship between Skp2 and Ku70 proteins. RESULTS: We first observed Skp2 and Ku70 mRNAs were significantly increased in cervical cancer tissues. And we identified Ku70 as a Skp2-binding protein and the binding site located in the C-terminal of Ku70 protein. We further found that Skp2 knockdown decreased the Ku70 protein level in cells, and increase the cellular apoptosis and DNA damage, suggesting Skp2 mediates the Ku70 protein stability and function via post-translational modification. CONCLUSION: The direct interaction between Skp2 and Ku70 proteins mediates the DNA damage repair and cellular apoptosis by regulating Ku70 stability and function via post-translational modification. The molecular mechanisms how Skp2 stabilize Ku70 would be clarified in our following research work.


Assuntos
Apoptose , Dano ao DNA , Reparo do DNA , Autoantígeno Ku/metabolismo , Processamento de Proteína Pós-Traducional , Proteínas Quinases Associadas a Fase S/metabolismo , Neoplasias do Colo do Útero/patologia , Feminino , Humanos , Autoantígeno Ku/genética , Proteínas Quinases Associadas a Fase S/genética , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/metabolismo
16.
Nat Commun ; 11(1): 3007, 2020 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-32522997

RESUMO

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

17.
Ann Clin Lab Sci ; 50(3): 412-416, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32581037

RESUMO

Rhabdomyosarcoma (RMS) is a primitive embryonal mesenchymal neoplasm demonstrating skeletal muscle differentiation. Diagnosis of RMS remains difficult due to the diversity of clinical features, pathological forms, and lesion's locations. Immunohistochemistry and Fluorescence in Situ Hybridization are common methods used to aid RMS diagnosis. In this research we tested protein expression of Desmin (Clone MX046), MyoD1 (Clone MX049), MyoD1 (Clone 5.8A), MyoD1 (Clone EP212), Myogenin (Clone F5D), and cytogenetic features in 21 RMS cases, with following results: positive rates of Desmin (Clone MX046), MyoD1 (Clone MX049), MyoD1 (Clone 5.8A), MyoD1 (Clone EP212) and Myogenin (Clone F5D) were 100.00%, 100.00%, 90.48%, 95.24% and 85.71%, respectively, with cytoplasmic stains of MyoD1 (Clone 5.8A) in 38.10% (8/21) cases and only nuclear stains of MyoD1 (Clone EP212), MyoD1 (Clone MX049) in all positive cases. FOXO1 gene was detected apart in 9 alveolar RMS samples, where MyoD1 (Clone MX049), MyoD1 (Clone 5.8A) and MyoD1 (Clone EP212) were 100% positive but MyoD1 (Clone 5.8A) only 44.44% (4/9). Thus we believe MyoD1 (Clone MX049) performs more sensitive and specific than MyoD1 (Clone 5.8A) and MyoD1 (Clone EP212).


Assuntos
Anticorpos Monoclonais/imunologia , Rabdomiossarcoma/diagnóstico , Rabdomiossarcoma/imunologia , Adolescente , Adulto , Anticorpos Monoclonais/metabolismo , Biomarcadores Tumorais , China , Desmina/genética , Desmina/imunologia , Diagnóstico Diferencial , Feminino , Fluorescência , Humanos , Imuno-Histoquímica , Hibridização in Situ Fluorescente , Masculino , Pessoa de Meia-Idade , Proteína MyoD/imunologia , Proteína MyoD/metabolismo , Miogenina/genética , Miogenina/imunologia , Rabdomiossarcoma/metabolismo
18.
Nat Commun ; 11(1): 2304, 2020 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-32385231

RESUMO

The organic-inorganic hybrid lead halide perovskites have emerged as a series of star materials for solar cells, lasers and detectors. However, the issues raised by the toxic lead element and marginal stability due to the volatile organic components have severely limited their potential applications. In this work, we develop a nucleation-controlled solution method to grow large size high-quality Cs3Bi2I9 perovskite single crystals (PSCs). Using the technique, we harvest some centimeter-sized single crystals and achieved high device performance. We find that X-ray detectors based on PSCs exhibit high sensitivity of 1652.3 µC Gyair-1 cm-2 and very low detectable dose rate of 130 nGyair s-1, both desired in medical diagnostics. In addition, its outstanding thermal stability inspires us to develop a high temperature X-ray detector with stable response at up to 100 °C. Furthermore, PSCs exhibit high X-ray imaging capability thanks to its negligible signal drifting and extremely high stability.

19.
Angew Chem Int Ed Engl ; 59(29): 11856-11860, 2020 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-32270587

RESUMO

Semiconductive metal-organic frameworks (MOFs) have emerged in applications such as chemical sensors, electrocatalysts, energy storage materials, and electronic devices. However, examples of semiconductive MOFs within flexible electronics have not been reported. We present flexible X-ray detectors prepared by thermoplastic dispersal of a semiconductive MOF (SCU-13) through a commercially available polymer, poly(vinylidene fluoride). The flexible detectors exhibit efficient X-ray-to-electric current conversion with enhanced charge-carrier mobility and low trap density compared to pelleted devices. A high X-ray detection sensitivity of 65.86 µCGyair -1 cm-2 was achieved, which outperforms other pelleted devices and commercial flexible X-ray detectors. We demonstrate that the MOF-based flexible detectors can be operated at multiple bending angles without a deterioration in detection performance. As a proof-of-concept, an X-ray phase contrast under bending conditions was constructed using a 5×5 pixelated MOF-based imager.

20.
J Am Chem Soc ; 142(18): 8342-8351, 2020 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-32279505

RESUMO

Hybrid layered halide perovskites have achieved impressive performance in optoelectronics. New structural types in the two-dimensional (2D) halide system such as the Dion-Jacobson phases have attracted wide research attention due to the short interlayer distance and unique layer orientation that facilitate better charge-transport and higher stability in optoelectronic devices. Here, we report the first solid solution series incorporating both A and A' cations in the 2D Dion-Jacobson family, with the general formula (A')(A)Pb2Br7 ((A' = 3-(aminomethyl)piperidinium (3AMP) and 4-(aminomethyl)piperidinium) (4AMP); A = methylammonium (MA) and formamidinium (FA)). Mixing the spacing A' cations and perovskitizer A cations generates the new (3AMP)a(4AMP)1-a(FA)b(MA)1-bPb2Br7 perovskites. The crystallographically refined crystal structures using single-crystal X-ray diffraction data reveal that the distortion of the inorganic framework is heavily influenced by the degree of A' and A alloying. A rising fraction of 4AMP in the structure, decreases the Pb-Br-Pb angles, making the framework more distorted. On the contrary, higher FA fractions increase the Pb-Br-Pb angles. This structural evolution fine-tunes the optical properties where the larger the Pb-Br-Pb angle, the narrower the band gap. The photoluminescence emission energy mirrors this trend. Raman spectroscopy reveals a highly dynamical lattice similar to MAPbBr3 and consistent with the local distortion environment of the [Pb2Br7] framework. Density functional theory (DFT) calculations of the electronic structures reveal the same trend as the experimental results where (3AMP)(FA)Pb2Br7 has the smallest band gap while (4AMP)(MA)Pb2Br7 has the largest band gap. The structural effects from solely the organic cations in the 2D system highlight the importance of understanding the high sensitivity of the optoelectronic properties on the structural tuning in this broad class of materials.

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