RESUMO
Free from strategically important elements such as lithium, nickel, cobalt, and copper, potassium-ion batteries (PIBs) are heralded as promising low-cost and sustainable electrochemical energy storage systems that complement the existing lithium-ion batteries (LIBs). However, the reported electrochemical performance of PIBs is still suboptimal, especially under practically relevant battery manufacturing conditions. The primary challenge stems from the lack of electrolytes capable of concurrently supporting both the low-voltage anode and high-voltage cathode with satisfactory Coulombic efficiency (CE) and cycling stability. Herein, we report a promising electrolyte that facilitates the commercially mature graphite anode (> 3 mAh cm-2) to achieve an initial CE of 91.14% (with an average cycling CE around 99.94%), fast redox kinetics, and negligible capacity fading for hundreds of cycles. Meanwhile, the electrolyte also demonstrates good compatibility with the 4.4 V (vs. K+/K) high-voltage K2Mn[Fe(CN)6] (KMF) cathode. Consequently, the KMF||graphite full-cell without precycling treatment of both electrodes can provide an average discharge voltage of 3.61 V with a specific energy of 316.5 Wh kg-1-(KMF+graphite), comparable to the LiFePO4||graphite LIBs, and maintain 71.01% capacity retention after 2000 cycles.
RESUMO
OBJECTIVE: We developed a few-shot learning (FSL) framework for the diagnosis of osteopenia and osteoporosis in knee X-ray images. METHODS: Computer vision models containing deep convolutional neural networks were fine-tuned to enable generalization from natural images (ImageNet) to chest X-ray images (normal vs. pneumonia, base images). Then, a series of automated machine learning classifiers based on the Euclidean distances of base images were developed to make predictions for novel images (normal vs. osteopenia vs. osteoporosis). The performance of the FSL framework was compared with that of junior and senior radiologists. In addition, the gradient-weighted class activation mapping algorithm was used for visual interpretation. RESULTS: In Cohort #1, the mean accuracy (0.728) and sensitivity (0.774) of the FSL models were higher than those of the radiologists (0.512 and 0.448). A diagnostic pipeline of FSL model (first)-radiologists (second) achieved better performance (0.653 accuracy, 0.582 sensitivity, and 0.816 specificity) than radiologists alone. In Cohort #2, the diagnostic pipeline also showed improved performance. CONCLUSIONS: The FSL framework yielded practical performance with respect to the diagnosis of osteopenia and osteoporosis in comparison with radiologists. This retrospective study supports the use of promising FSL methods in computer-aided diagnosis tasks involving limited samples.
Assuntos
Doenças Ósseas Metabólicas , Osteoporose , Humanos , Osteoporose/diagnóstico por imagem , Osteoporose/diagnóstico , Doenças Ósseas Metabólicas/diagnóstico por imagem , Doenças Ósseas Metabólicas/diagnóstico , Feminino , Masculino , Pessoa de Meia-Idade , Idoso , Joelho/diagnóstico por imagem , Joelho/patologia , Algoritmos , Redes Neurais de Computação , Aprendizado de Máquina , Radiografia/métodos , Adulto , Estudos Retrospectivos , Articulação do Joelho/diagnóstico por imagem , Articulação do Joelho/patologia , Diagnóstico por Computador/métodosRESUMO
We herein report a "Fight Aggregation with Aggregation" (FAA) approach for redirection of amyloid-ß peptide (Aß) aggregation using a europium(III) complex (EuL3) that can undergo H-aggregation in aqueous solution under physiological conditions. The H-aggregates of EuL3 may serve as scaffolds that can facilitate the accumulation of Aß to form non-fibrillar co-assemblies. As a result, the Aß aggregation-induced cytotoxicity was inhibited.
Assuntos
Peptídeos beta-Amiloides , Complexos de Coordenação , Európio , Agregados Proteicos , Európio/química , Európio/farmacologia , Peptídeos beta-Amiloides/metabolismo , Peptídeos beta-Amiloides/química , Complexos de Coordenação/química , Complexos de Coordenação/farmacologia , Complexos de Coordenação/síntese química , Agregados Proteicos/efeitos dos fármacos , Humanos , Sobrevivência Celular/efeitos dos fármacos , AnimaisRESUMO
Coxsackievirus B3 (CVB3) triggers viral myocarditis, with no effective vaccine yet. This fecal-oral transmitted pathogen has prompted interest in mucosal immunization strategies to impede CVB3 spread. We developed a new attenuated vaccine strain, named CVB3(mu). The potential of CVB3(mu) to stimulate mucosal immune protection remains to be elucidated. This study evaluates the attenuation characteristics of CVB3(mu) via a rapid evolution cellular model and RNA sequencing. Its temperature sensitivity and safety were evaluated through in vitro and in vivo experiments. The mucosal immunity protection of CVB3(mu) was assessed via intranasal immunization in Balb/c mice. The results indicate that CVB3(mu) exhibits temperature sensitivity and forms smaller plaques. It sustains fewer genetic mutations and still possesses certain attenuated traits up to the 25th passage, in comparison to CVB3(WT). Intranasal immunization elicited a significant serum neutralizing antibodies, and a substantial sIgA response in nasal washes. In vivo trials revealed CVB3(mu) protection in adult mice and passive protection in suckling mice against lethal CVB3(WT) challenges. In conclusion, CVB3(mu), a live attenuated intranasal vaccine, provides protection involving humoral and mucosal immunity, making it a promising candidate to control CVB3 spread and infection.
Assuntos
Administração Intranasal , Anticorpos Neutralizantes , Anticorpos Antivirais , Infecções por Coxsackievirus , Enterovirus Humano B , Imunidade nas Mucosas , Camundongos Endogâmicos BALB C , Vacinas Atenuadas , Vacinas Virais , Animais , Enterovirus Humano B/imunologia , Vacinas Atenuadas/imunologia , Vacinas Atenuadas/administração & dosagem , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Infecções por Coxsackievirus/imunologia , Infecções por Coxsackievirus/prevenção & controle , Vacinas Virais/imunologia , Vacinas Virais/administração & dosagem , Camundongos , Imunoglobulina A Secretora/imunologia , Humanos , Feminino , Modelos Animais de DoençasRESUMO
Background: Although the research reports on locally advanced breast cancer (LABC) are increasing year by year, there are few reports on T1 LABC axillary lymph node metastasis (ALNM). By establishing a prediction model for T1 LABC ALNM, this study provides a reference value for the probability of ALNM of related patients, which helps clinicians to develop a more effective and individualized treatment plan for LABC. Methods: Cases with pathologically confirmed T1 breast cancer (BC) between 2010 and 2015 in the Surveillance, Epidemiology, and End Results (SEER) database were identified. Logistic regression was used to analyze the correlation between LABC lymph node metastasis and every factor, and the odds ratio (OR) and 95% confidence interval (CI) were used to identify any influencing factors. A nomogram was drawn after incorporating meaningful factors identified in multivariate logistic regression into the model. The receiver operating characteristic (ROC) curve of the model was drawn, and the area under the curve (AUC) and its 95% CI were calculated. Hosmer-Lemeshow goodness-of-fit test and clinical decision curve analysis (DCA) were performed. The results were validated in the validation group. Results: A total of 200,933 female T1 BC patients were included in this study. Univariate and multivariate logistic regression analysis of T1 BC showed that progesterone receptor (PR)-negative, race, age, lobular carcinoma, micropapillary ductal carcinoma, axillary tail tumor, poor differentiation, and larger tumor diameter increased the probability of ALNM in T1 LABC. A predictive nomogram was established using the above predictors, the AUC of the modeling group was 0.739 (95% CI: 0.732-0.747), and when the AUC cut-off value was 0.026, the specificity and sensitivity of the model were 65.78% and 69.99%, respectively. Validation of the model showed that the AUC of the validation group (n=60,280) was 0.741. When all the risk factors were met, the predicted probability of N2-N3 was 50.40%. Conclusions: In this study, it was found that PR-negative, Black race, age, lobular carcinoma, micropapillary ductal carcinoma, axillary tail tumor, poor differentiation, and tumor diameter increased the probability of large lymph node metastasis in T1 LABC small tumors.
RESUMO
The limited oxidation stability of ether solvents has posed significant challenges for their applications in high-voltage lithium metal batteries (LMBs). To tackle this issue, the prevailing strategy either adopts a high concentration of fluorinated salts or relies on highly fluorinated solvents, which will significantly increase the manufacturing cost and create severe environmental hazards. Herein, an alternative and sustainable salt engineering approach is proposed to enable the utilization of dilute electrolytes consisting of fluorine (F)-free ethers in high-voltage LMBs. The proposed 0.8â M electrolyte supports stable lithium plating-stripping with a high Coulombic efficiency of 99.47 % and effectively mitigates the metal dissolution, phase transition, and gas release issues of the LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode upon charging to high voltages. Consequently, the 4.5â V high-loading Li||NCM 811â cell shows a capacity retention of 75.2 % after 300 cycles. Multimodal experimental characterizations coupled with theoretical investigations demonstrate that the boron-containing salt plays a pivotal role in forming the passivation layers on both anode and cathode. The present simple and cost-effective electrolyte design strategy offers a promising and alternative avenue for using commercially mature, environmentally benign, and low-cost F-free ethers in high-voltage LMBs.
RESUMO
Background: Cytomegalovirus (CMV) reactivation is a significant concern following allogeneic stem cell transplantation. While previous research has highlighted the anti-CMV reactivation effect of γδ T cells in immunocompromised transplant patients, their characterization in recipients at high risk of CMV reactivation remains limited. Methods: This study focused on D+/R+ recipients (where both donor and recipient are CMV seropositive) at high risk of CMV reactivation. We analyzed 28 patients who experienced CMV recurrence within 100 days post-allogeneic hematopoietic stem cell transplantation, along with 36 matched recipients who did not experience CMV recurrence. Clinical data from both groups were compared, and risk factors for CMV reactivation were identified. Additionally, CMV viral load was measured, and flow cytometric analysis was conducted to assess changes in peripheral blood γδ T cell proportions, subpopulation distribution, and differentiation status. We also analyzed the CDR3 repertoire of the TCR δ chain in different γδ T cell subsets. Functional analysis was performed by measuring the lysis of CMV-infected cells upon stimulation. Results: CMV reactivation post-transplantation was associated with acute graft-versus-host disease (aGvHD) and reactivation of non-CMV herpesviruses. Notably, CMV reactivation led to sustained expansion of γδ T cells, primarily within the Vδ2neg γδ T cell subpopulation, with a trend toward differentiation from Naive to effector memory cells. Analysis of the δ chain CDR3 repertoire revealed a delay in the reconstitution of clonal diversity in Vδ2neg γδ T cells following CMV reactivation, while Vδ2pos T cells remained unaffected. Upon stimulation with CMV-infected MRC5 cells, the Vδ2neg γδ T cell subpopulation emerged as the primary effector cell group producing IFN-γ and capable of lysing CMV-infected cells. Moreover, our findings suggest that NKG2D is not necessary involved in Vδ2neg γδ T cell-mediated anti-CMV cytotoxicity. Conclusion: This study provides novel insights into the role of γδ T cells in the immune response to CMV reactivation in transplantation recipients at high risk of CMV infection. Specifically, the Vδ2neg γδ T cell subpopulation appears to be closely associated with CMV reactivation, underscoring their potential role in controlling infection and reflecting CMV reactivation in HSCT patients.
Assuntos
Infecções por Citomegalovirus , Citomegalovirus , Transplante de Células-Tronco Hematopoéticas , Receptores de Antígenos de Linfócitos T gama-delta , Transplante Homólogo , Ativação Viral , Humanos , Infecções por Citomegalovirus/imunologia , Infecções por Citomegalovirus/virologia , Masculino , Citomegalovirus/imunologia , Citomegalovirus/fisiologia , Ativação Viral/imunologia , Feminino , Adulto , Pessoa de Meia-Idade , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Receptores de Antígenos de Linfócitos T gama-delta/metabolismo , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Doença Enxerto-Hospedeiro/imunologia , Adulto Jovem , Células T de Memória/imunologia , IdosoRESUMO
Transforming growth factor ß1 (TGF-ß1) has a neuroprotective function in traumatic brain injury (TBI) through its anti-inflammatory and immunomodulatory properties. However, the precise mechanisms underlying the neuroprotective actions of TGF-ß1 on the cortex require further investigation. In this study, we were aimed to investigate the regulatory function of TGF-ß1 on neuronal autophagy and apoptosis using an in vitro primary cortical neuron trauma-injury model. LDH activity was assayed to measure cell viability, and intracellular [Ca2+] was measured using Fluo-4-AM in an in vitro primary cortical neuron trauma-injury model. RNA-sequencing (RNAseq), immunofluorescent staining, transmission electron microscopy (TEM), western blot and CTSD activity detection were employed. We observed significant enrichment of DEGs related to autophagy, apoptosis, and the lysosome pathway in trauma-injured cortical neurons. TEM confirmed the presence of autophagosomes as well as autophagolysosomes. Western blot revealed upregulation of autophagy-related protein light chain 3 (LC3-II/LC3-I), sequestosome 1 (SQSTM1/p62), along with apoptosis-related protein cleaved-caspase 3 in trauma-injured primary cortical neurons. Furthermore, trauma-injured cortical neurons showed an upregulation of lysosomal marker protein (LAMP1) and lysosomal enzyme mature cathepsin D (mCTSD), but a decrease in the activity of CTSD enzyme. These results indicated that apoptosis was up-regulated in trauma- injured cortical neurons at 24 h, accompanied by lysosomal dysfunction and impaired autophagic flux. Notably, TGF-ß1 significantly reversed these changes. Our results suggested that TGF-ß1 exerted neuroprotective effects on trauma- injured cortical neurons by reducing lysosomal dysfunction, decreasing the accumulation of autophagosomes and autophagolysosomes, and enhancing autophagic flux.
RESUMO
Sodium-ion battery (SIB) is a candidate for the stationary energy storage systems because of the low cost and high abundance of sodium. However, the energy density and lifespan of SIBs suffer severely from the irreversible consumption of the Na-ions for the formation of the solid electrolyte interphase (SEI) layer and other side reactions on the electrodes. Here, Na3.5C6O6 is proposed as an air-stable high-efficiency sacrificial additive in the cathode to compensate for the lost sodium. It is characteristic of low desodiation (oxidation) potential (3.4-3.6 V vs. Na+/Na) and high irreversible desodiation capacity (theoretically 378 mAh g-1). The feasibility of using Na3.5C6O6 as a sodium compensation additive is verified with the improved electrochemical performances of a Na2/3Ni1/3Mn1/3Ti1/3O2ÇÇhard carbon cells and cells using other cathode materials. In addition, the structure of Na3.5C6O6 and its desodiation path are also clarified on the basis of comprehensive physical characterizations and the density functional theory (DFT) calculations. This additive decomposes completely to supply abundant Na ions during the initial charge without leaving any electrochemically inert species in the cathode. Its decomposition product C6O6 enters the carbonate electrolyte without bringing any detectable negative effects. These findings open a new avenue for elevating the energy density and/or prolonging the lifetime of the high-energy-density secondary batteries.
RESUMO
In this paper, the principles of spectral data cube reconstruction based on an integral field snapshot imaging spectrometer and GPU-based acceleration are presented. The primary focus is on improving the reconstruction algorithm using GPU parallel computing technology to enhance the computational efficiency for real-time applications. And the computational tasks of the spectral reconstruction algorithm were transferred to the GPU through program parallelization and memory optimization, resulting in significant performance gains. Experimental results indicate that the average processing time of the GPU-based parallel algorithm is approximately 29.43â ms, showing a substantial acceleration ratio of about 14.27 compared to the traditional CPU serial algorithm with an average processing time of around 420.46â ms. The study aims to refine the GPU parallelization algorithm for continued improvement in computational efficiency and overall performance. The anticipated applications of this research include providing crucial technical support for the perception and monitoring of crop growth traits in agricultural production, contributing to the modernization and advancement of intelligence in the field.
RESUMO
Androgen receptor (AR) has been extensively established as a potential therapeutic target for nearly all stages of prostate cancer (PCa). However, acquired resistance to AR-targeted drugs inevitably develops and severely limits their clinical efficacy. Particularly, there currently exists no efficient treatment for patients expressing the constitutively active AR splice variants, such as AR-V7. Herein, we report the structure-activity relationship studies of 55 N-heterocycle-substituted hydantoins, which identified the structural motifs required for AR/AR-V7 degradation. Among them, the most potent compound 27c exhibited selective AR/AR-V7 degradation over other hormone receptors and excellent antiproliferative activities in LNCaP and 22RV1 cells. RNA sequence analysis confirmed that 27c effectively suppressed transcriptional activity of the AR signaling pathway. Importantly, 27c demonstrated potent antitumor efficacy in an enzalutamide-resistant 22RV1 xenograft model. These results highlight the potential of 27c as a promising dual AR/AR-V7 degrader for overcoming drug resistance in advanced PCa expressing AR splice variants.
Assuntos
Neoplasias de Próstata Resistentes à Castração , Receptores Androgênicos , Masculino , Humanos , Receptores Androgênicos/metabolismo , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Linhagem Celular Tumoral , Transdução de Sinais , Relação Estrutura-Atividade , Nitrilas/farmacologia , Resistencia a Medicamentos AntineoplásicosRESUMO
To address the problems associated with Li metal anodes, a fluoride-rich solid-like electrolyte (SLE) that combines the benefits of solid-state and liquid electrolytes is presented. Its unique triflate-group-enhanced frame channels facilitate the formation of a functional inorganic-rich solid electrolyte interphase (SEI), which not only improves the reversibility and interfacial charge transfer of Li anodes but also ensures uniform and compact Li deposition. Furthermore, these triflate groups contribute to the decoupling of Li+ and provide hopping sites for rapid Li+ transport, enabling a high room-temperature ionic conductivity of 1.1 mS cm-1 and a low activation energy of 0.17 eV, making it comparable to conventional liquid electrolytes. Consequently, Li symmetric cells using such SLE achieve extremely stable plating/stripping cycling over 3500 h at 0.5 mA cm-2 and support a high critical current up to 2 mA cm-2. The assembled Li||LiFePO4 solid-like batteries exhibit exceptional cyclability for over 1 year and a half, even outperforming liquid cells. Additionally, high-voltage cylindrical cells and high-capacity pouch cells are demonstrated, corroborating much simpler processibility in battery assembly compared to all-solid-state batteries.
RESUMO
INTRODUCTION: Ascending aortic aneurysm is a serious health risk. In order to study ascending aortic aneurysms, elastase and calcium ion treatment for aneurysm formation are mainly used, but their aneurysm formation time is long and the aneurysm formation rate is low. Thus, this study aimed to construct a rat model of ascending aorta aneurysm with a short modeling time and high aneurysm formation rate, which may mimic the pathological processes of human ascending aorta aneurysm. METHODS: Cushion needles with different pipe diameters (1.0, 1.2, 1.4, and 1.6 mm) were used to establish a human-like rat model of ascending aortic aneurysm by narrowing the ascending aorta of rats and increasing the force of blood flow on the vessel wall. The vascular diameters were evaluated using color Doppler ultrasonography after 2 weeks. The characteristics of ascending aortic aneurysm in rats were detected by Masson's trichrome staining, Verhoeff's Van Gieson staining, and hematoxylin and eosin staining, while real-time polymerase chain reaction was utilized to assess the total RNA of cytokine interleukin-1ß, interleukin 6, transforming growth factor-beta 1, and metalloproteinase 2. RESULTS: Two weeks after surgery, the ultrasound images and the statistical analysis demonstrated that the diameter of the ascending aorta in rats increased more than 1.5 times, similar to that in humans, indicating the success of animal modeling of ascending aortic aneurysm. Moreover, the optimal constriction diameter of the ascending aortic aneurysm model is 1.4 mm by the statistical analysis of the rate of ascending aortic aneurysm and mortality rate in rats with different constriction diameters. CONCLUSIONS: The human-like ascending aortic aneurysm model developed in this study can be used for the studies of the pathological processes and mechanisms of ascending aortic aneurysm in a more clinically relevant fashion.
Assuntos
Aneurisma Aórtico , Modelos Animais de Doenças , Ratos Sprague-Dawley , Animais , Ratos , Humanos , Aneurisma Aórtico/patologia , Masculino , Aorta/patologia , Aorta/diagnóstico por imagem , Fator de Crescimento Transformador beta1/metabolismo , Metaloproteinase 2 da Matriz/metabolismo , Aneurisma da Aorta AscendenteRESUMO
Halide solid electrolytes, known for their high ionic conductivity at room temperature and good oxidative stability, face notable challenges in all-solid-state Li-ion batteries (ASSBs), especially with unstable cathode/solid electrolyte (SE) interface and increasing interfacial resistance during cycling. In this work, we have developed an Al3+-doped, cation-disordered epitaxial nanolayer on the LiCoO2 surface by reacting it with an artificially constructed AlPO4 nanoshell; this lithium-deficient layer featuring a rock-salt-like phase effectively suppresses oxidative decomposition of Li3InCl6 electrolyte and stabilizes the cathode/SE interface at 4.5â V. The ASSBs with the halide electrolyte Li3InCl6 and a high-loading LiCoO2 cathode demonstrated high discharge capacity and long cycling life from 3 to 4.5â V. Our findings emphasize the importance of specialized cathode surface modification in preventing SE degradation and achieving stable cycling of halide-based ASSBs at high voltages.
RESUMO
DNA polymerase theta (Polθ) has recently emerged as a new attractive synthetic lethal target involved in DNA damage repair. Inactivating Polθ alone or in combination with PARP inhibitors has demonstrated substantial therapeutic potential against tumors with homologous recombination (HR) defects such as alternation of BRCA genes. Herein, we report the design and proof of concept of a highly potent dual Polθ/PARP inhibitor 25d, which exhibited low nanomolar inhibitory activities against both Polθ and PARP1. Compared to combination treatment, 25d demonstrated superior antitumor efficacy in both MDA-MB-436 cells and xenografts by inducing more DNA damage and apoptosis. Importantly, 25d retained sensitivity in PARP inhibitor-resistant MDA-MB-436 cells with 53BP1 defect. Altogether, these findings illustrate the potential advantages of 25d, a first-in-class dual Polθ/PARP inhibitor, over monotherapy in treating HR-deficient tumors, including those with acquired PARP inhibitor resistance.
Assuntos
Antineoplásicos , Neoplasias , Humanos , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Neoplasias/tratamento farmacológico , Reparo do DNA , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Recombinação Homóloga , Linhagem Celular TumoralRESUMO
Two-dimensional moiré materials are formed by overlaying two layered crystals with small differences in orientation or/and lattice constant, where their direct coupling generates moiré potentials. Moiré materials have emerged as a platform for the discovery of new physics and device concepts, but while moiré materials are highly tunable, once formed, moiré lattices cannot be easily altered. Here we demonstrate the electrostatic imprinting of moiré lattices onto a target monolayer semiconductor. The moiré potential-created by a lattice of electrons that is supported by a Mott insulator state in a remote MoSe2/WS2 moiré bilayer-imprints a moiré potential that generates flat bands and correlated insulating states in the target monolayer and can be turned on/off by gate tuning the doping density of the moiré bilayer. Additionally, we studied the interplay between the electrostatic and structural relaxation contributions to moiré imprinting. Our results demonstrate a pathway towards gate control of moiré lattices.
RESUMO
The increasing demand for accurate imaging spectral information in remote sensing detection has driven the development of hyperspectral remote sensing instruments towards a larger view field and higher resolution. As the core component of the spectrometer slit, the designed length reaches tens of millimeters while the precision maintained within the µm level. Such precision requirements pose challenges to traditional machining and laser processing. In this paper, a high-precision air slit was created with a large aspect ratio through MEMS technology on SOI silicon wafers. In particular, a MEMS slit was prepared with a width of 15 µm and an aspect ratio exceeding 4000:1, and a spectral spectroscopy system was created and tested with a Hg-Cd light source. As a result, the spectral spectrum was linear within the visible range, and a spectral resolution of less than 1 nm was obtained. The standard deviation of resolution is only one-fourth of that is seen in machined slits across various view fields. This research provided a reliable and novel manufacturing technique for high-precision air slits, offering technical assistance in developing high-resolution wide-coverage imaging spectrometers.
RESUMO
The explorations of new three-dimensional (3D) microporous metal halides, especially the iodoargentate-based hybrids, and understanding of their structure-activity relationships are still quite essential but full of great challenges. Herein, with the aromatic 4,4'-dpa (4,4'-dpa = 4,4'-dipyridylamine) ligands as the structural directing agents, we solvothermal synthesized and structurally characterized a novel member of microporous iodoargentate family, namely [H2-4,4'-dpa]Ag6I8 (1). Compound 1 possesses a unique and complicated 3D [Ag6I8]n2n- anionic architecture that was built up from the unusual hexameric [Ag6I13] secondary building units (SBUs). Research on optical properties indicated that compound 1 exhibited semiconductor behavior, with an optical band gap of 2.50 eV. Under the alternate irradiation of light, prominent photoelectric switching abilities could be achieved by compound [H2-4,4'-dpa]Ag6I8, whose photocurrent densities (0.37 µA·cm-2 for visible light and 1.23 µA·cm-2 for full-spectrum) compared well with or exceeded those of some high-performance halide counterparts. Further theoretical calculations revealed that the relatively dispersed conduction bands (CBs) structures in compound 1 induced higher electron mobilities, which may be responsible for its good photoelectricity. Presented in this work also comprised the analyses of Hirshfeld surface, powder X-ray diffractometer (PXRD), thermogravimetric measurement, energy-dispersive X-ray spectrum (EDX) along with X-ray photoelectron spectroscopy (XPS).
RESUMO
Chern insulators, which are the lattice analogues of the quantum Hall states, can potentially manifest high-temperature topological orders at zero magnetic field to enable next-generation topological quantum devices1-3. Until now, integer Chern insulators have been experimentally demonstrated in several systems at zero magnetic field3-8, whereas fractional Chern insulators have been reported in only graphene-based systems under a finite magnetic field9,10. The emergence of semiconductor moiré materials11, which support tunable topological flat bands12,13, provides an opportunity to realize fractional Chern insulators13-16. Here we report thermodynamic evidence of both integer and fractional Chern insulators at zero magnetic field in small-angle twisted bilayer MoTe2 by combining the local electronic compressibility and magneto-optical measurements. At hole filling factor ν = 1 and 2/3, the system is incompressible and spontaneously breaks time-reversal symmetry. We show that they are integer and fractional Chern insulators, respectively, from the dispersion of the state in the filling factor with an applied magnetic field. We further demonstrate electric-field-tuned topological phase transitions involving the Chern insulators. Our findings pave the way for the demonstration of quantized fractional Hall conductance and anyonic excitation and braiding17 in semiconductor moiré materials.
RESUMO
Islet transplantation has poor long-term efficacy because of the lack of extracellular matrix support and neovascularization; this limits its wide application in diabetes research. In this study, we develop a 3D-printed islet organoid by combining a pancreatic extracellular matrix (pECM) and hyaluronic acid methacrylate (HAMA) as specific bioinks. The HAMA/pECM hydrogel was validated in vitro to maintain islet cell adhesion and morphology through the Rac1/ROCK/MLCK signaling pathway, which helps improve islet function and activity. Further, in vivo experiments confirmed that the 3D-printed islet-encapsulated HAMA/pECM hydrogel increases insulin levels in diabetic mice, maintains blood glucose levels within a normal range for 90 days, and rapidly secretes insulin in response to blood glucose stimulation. In addition, the HAMA/pECM hydrogel can facilitate the attachment and growth of new blood vessels and increase the density of new vessels. Meanwhile, the designed 3D-printed structure was conducive to the formation of vascular networks and it promoted the construction of 3D-printed islet organoids. In conclusion, our experiments optimized the HAMA/pECM bioink composition and 3D-printed structure of islet organoids with promising therapeutic effects compared with the HAMA hydrogel group that can be potentially used in clinical applications to improve the effectiveness and safety of islet transplantation in vivo. STATEMENT OF SIGNIFICANCE: The extraction process of pancreatic islets can easily cause damage to the extracellular matrix and vascular system, resulting in poor islet transplantation efficiency. We developed a new tissue-specific bioink by combining pancreatic extracellular matrix (pECM) and hyaluronic acid methacrylate (HAMA). The islet organoids constructed by 3D printing can mimic the microenvironment of the pancreas and maintain islet cell adhesion and morphology through the Rac1/ROCK/MLCK signaling pathway, thereby improving islet function and activity. In addition, the 3D-printed structures we designed are favorable for the formation of new blood vessel networks, bringing hope for the long-term efficacy of islet transplantation.