Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 116
Filtrar
Mais filtros

País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Cell ; 183(6): 1665-1681.e18, 2020 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-33188776

RESUMO

We present deterministic barcoding in tissue for spatial omics sequencing (DBiT-seq) for co-mapping of mRNAs and proteins in a formaldehyde-fixed tissue slide via next-generation sequencing (NGS). Parallel microfluidic channels were used to deliver DNA barcodes to the surface of a tissue slide, and crossflow of two sets of barcodes, A1-50 and B1-50, followed by ligation in situ, yielded a 2D mosaic of tissue pixels, each containing a unique full barcode AB. Application to mouse embryos revealed major tissue types in early organogenesis as well as fine features like microvasculature in a brain and pigmented epithelium in an eye field. Gene expression profiles in 10-µm pixels conformed into the clusters of single-cell transcriptomes, allowing for rapid identification of cell types and spatial distributions. DBiT-seq can be adopted by researchers with no experience in microfluidics and may find applications in a range of fields including developmental biology, cancer biology, neuroscience, and clinical pathology.


Assuntos
Código de Barras de DNA Taxonômico , Genômica , Especificidade de Órgãos/genética , Animais , Automação , Encéfalo/embriologia , Análise por Conglomerados , DNA Complementar/genética , Embrião de Mamíferos/metabolismo , Olho/embriologia , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Camundongos Endogâmicos C57BL , Microfluídica , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reprodutibilidade dos Testes , Análise de Célula Única , Transcriptoma/genética
2.
Nature ; 623(7987): 531-537, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37853122

RESUMO

Achieving both high efficiency and long-term stability is the key to the commercialization of perovskite solar cells (PSCs)1,2. However, the diversity of perovskite (ABX3) compositions and phases makes it challenging to fabricate high-quality films3-5. Perovskite formation relies on the reaction between AX and BX2, whereas most conventional methods for film-growth regulation are based solely on the interaction with the BX2 component. Herein, we demonstrate an alternative approach to modulate reaction kinetics by anion-π interaction between AX and hexafluorobenzene (HFB). Notably, these two approaches are independent but work together to establish 'dual-site regulation', which achieves a delicate control over the reaction between AX and BX2 without unwanted intermediates. The resultant formamidinium lead halides (FAPbI3) films exhibit fewer defects, redshifted absorption and high phase purity without detectable nanoscale δ phase. Consequently, we achieved PSCs with power conversion efficiency (PCE) up to 26.07% for a 0.08-cm2 device (25.8% certified) and 24.63% for a 1-cm2 device. The device also kept 94% of its initial PCE after maximum power point (MPP) tracking for 1,258 h under full-spectrum AM 1.5 G sunlight at 50 ± 5 °C. This method expands the range of chemical interactions that occur in perovskite precursors by exploring anion-π interactions and highlights the importance of the AX component as a new and effective working site to improved photovoltaic devices with high quality and phase purity.

3.
Opt Express ; 32(10): 18237-18246, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38858985

RESUMO

Quantum random numbers play a crucial role in diverse applications, including cryptography, simulation, and artificial intelligence. In contrast to predictable algorithm-based pseudo-random numbers, quantum physics provides new avenues for generating theoretically true random numbers by exploiting the inherent uncertainty contained in quantum phenomena. Here, we propose and demonstrate a quantum random number generator (QRNG) using a prepared broadband squeezed state of light, where the randomness of the generated numbers entirely originates from the quantum noise introduced by squeezing operation rather than vacuum noise. The relationship between entropy rate and squeezing level is analyzed. Furthermore, we employ a source-independent quantum random number protocol to enhance the security of the random number generator.

4.
Opt Express ; 32(10): 17028-17037, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38858895

RESUMO

Efficient diode-pumped continuous-wave (CW) and wavelength tunable Tm:YAP lasers based on the vibronic and electronic transitions are investigated. A total maximum output power of 4.1 W is achieved with multi-wavelength output around 2162 nm and 2274 nm, corresponding to a slope efficiency of 29.8% for a 3 at. % Tm:YAP crystal. A maximum output power of 2.48 W with a slope efficiency of 25.4% is obtained at 2146 nm for a 4 at. % Tm:YAP crystal. Using a birefringent filter (BF), the emission wavelengths of the Tm:YAP laser are tuned over spectral ranges of 59 nm from 2115 nm to 2174 nm and 127 nm from 2267 nm to 2394 nm, respectively, which is the first demonstration of wavelength tunable Tm:YAP laser based on the electronic transition 3H4→3H5 and vibronic transition 3F4→3H6, to the best of our knowledge. The results show great potentials of the Tm:YAP crystal for realizing efficient lasers in the spectral range of 2.1-2.4 µm.

5.
Phys Rev Lett ; 132(14): 140802, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38640392

RESUMO

Quantum dense coding (QDC) means to transmit two classical bits by only transferring one quantum bit, which has enabled high-capacity information transmission and strengthened system security. Continuous-variable QDC offers a promising solution to increase communication rates while achieving seamless integration with classical communication systems. Here, we propose and experimentally demonstrate a high-speed quantum radio-frequency-over-light (RFOL) communication scheme based on QDC with an entangled state, and achieve a practical rate of 20 Mbps through digital modulation and RFOL communication. This scheme bridges the gap between quantum technology and real-world communication systems, which bring QDC closer to practical applications and offer prospects for further enhancement of metropolitan communication networks.

6.
Langmuir ; 2024 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-38343282

RESUMO

Magnetic polymer composites have been widely utilized in potential applications in material science, such as reduction of dyes, immunodiagnostics, biomedicals, and magnetically controllable photonic crystals owing to large surface areas, fast separation, and recyclable performance. In this work, anisotropic magnetic particles were prepared by seeded emulsion polymerization, with morphologies of "Fe3O4-shell", "hemisphere-like", "raspberry-like", "multiple lobes-like", and "sandwich-like". Poly(styrene/divinylbenzene/mono-2-(methacryloxy)ethyl succinate)@ Fe3O4 (P(St/DVB/MMES)@Fe3O4) were the seed microspheres, and P(St/DVB/MMES)@Fe3O4@polymer particles are achieved by seeded emulsion polymerizations. The morphology of the particles depends on polymerization conditions (monomer ratios and surfactant), particle properties, and so on. Then, the minimum surface free energy change principles were used to predict the equilibrium morphologies of the magnetic polymer composites. Through theory, the model gives the correct tendency and good agreement with the equilibrium morphology which was in tandem with TEM results. Lastly, after in situ surface deposition of Ag nanoparticles, magnetic composite particles with sandwich-like morphology were applied for the catalytic degradation of 4-nitrophenol (4-NP) reacting with NaBH4. The apparent rate coefficient is 0.0069 s-1, and it can keep mainly about 80% efficiency in catalysis after five cycles.

7.
Ecotoxicol Environ Saf ; 271: 115953, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38244512

RESUMO

The widespread use of biogas slurry could potentially raise the environmental risk of antibiotics. Dissolved organic matter (DOM), as the most active part of biogas slurry, was able to interact with antibiotics and play a crucial role in the structure and function of soil and aquatic ecosystems. The recent shifts in global climate patterns have garnered significant attention due to their substantial impact on temperature, thereby exerting a direct influence on the characteristics of DOM and subsequently on the environmental behavior of antibiotics. However, there is limited research concerning the impact of temperature on the binding of DOM and antibiotics. Thus, this study aimed to explore the temperature-dependent structural transformation and driving factors of biogas slurry-derived DOM (BSDOM). Additionally, the binding characteristics between BSDOM and the commonly used antibiotic norfloxacin (NOR) at different temperatures were studied by using multi spectroscopic methods and two-dimensional correlation spectroscopy (2D-COS) analysis. The results suggested that the temperature-dependent structural transformation of BSDOM was reversible, with a slight lag in the transition temperature under cooling (13 °C for heating and 17 °C for cooling). Heating promoted the conversion of protein-like to humic-like substances while cooling favored the decomposition of humic-like substances. BSDOM and NOR were static quenching, with oxygen-containing functional groups such as C-O and -OH playing an important role. Temperature influenced the order of binding, the activity of the protein fraction, and its associated functional groups. At temperatures of 25 °C and 40 °C, the fluorescent components were observed to exhibit consistent binding preferences, whereby the humic-like component demonstrated a greater affinity for NOR compared to the protein-like component. However, the functional group binding order exhibited an opposite trend. At 10 °C, a new protein-like component appeared and bound preferentially to NOR, when no C-O stretch corresponding to the amide was observed. The finding will contribute to a comprehensive understanding of the interaction mechanisms between DOM and antibiotics under climate change, as well as providing a theoretical basis to reduce the environmental risks of biogas slurry and antibiotics.


Assuntos
Matéria Orgânica Dissolvida , Norfloxacino , Temperatura , Biocombustíveis , Ecossistema , Espectrometria de Fluorescência/métodos , Substâncias Húmicas/análise , Antibacterianos , Proteínas
8.
Small ; 19(21): e2300233, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36843293

RESUMO

Nowadays, the rapidly development of advanced antidetection technology raises stringent requirements for microwave absorption materials (MAMs) to focus more attention on wider bandwidth, thinner thickness, and lower density. Adding magnetic medium to realize broadband absorption may usually result in the decline of service performance and accelerating corrosion of MAMs. Chiral MAMs can produce extra magnetic loss without adding magnetic medium due to the unique electromagnetic cross polarization effect. However, more efforts should be taken to furtherly promote efficient bandwidth of chiral MAMs and reveal attenuation mode and modulation method of chiral structure. Herein, a novel superhelical nano-microstructure based on chiral polyaniline and helical polypyrrole is successfully achieved via in situ polymerization strategy. The enhanced multiscale-chiral synergistic effect contributes to broaden effective absorption bandwidth, covering 8.6 GHz at the thickness of 3.6 mm, and the minimum reflection loss can reach -51.3 dB simultaneously. Besides, to further explain response modes and loss mechanism of superhelical nano-microstructures, the electromagnetic simulation and test analysis are applied together to reveal their synergistic enhancement attenuation mechanism. Taken together, this strategy gives a new thought of how to design, prepare, and optimize the hierarchical structure materials to achieving broadband and high-performance microwave absorption.

9.
Opt Lett ; 48(21): 5599-5602, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37910712

RESUMO

A high-efficiency, high-energy, narrow bandwidth, hundred-nanosecond pulse width 355 nm ultraviolet (UV) laser was realized. A high-energy single-frequency 1064 nm fundamental laser was demonstrated firstly with multistage end-pumped preamplifiers and side-pumped main amplifiers. The corresponding pulse energy, repetition rate, pulse duration, bandwidth, and beam quality factor M2 were determined to be 221 mJ, 100 Hz, 156 ns, 2.25 MHz, and 1.23, respectively. By using type-I phase-matching LBO crystal for second harmonic generation (SHG) and type-II phase-matching LBO crystal for the sum frequency generation of the third harmonic, 67 mJ, a narrow bandwidth 355 nm UV laser was obtained with a pulse width of 137 ns and an energy stability of RMS < 1.2%@2 h. The fundamental to UV optical conversion efficiency was 30.3%. Our results provided a new way for generating high-energy, narrow bandwidth hundred-nanosecond 355 nm UV lasers used for direct-detection Doppler wind lidar (DWL) system.

10.
Opt Lett ; 48(10): 2768-2771, 2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-37186761

RESUMO

As the critical device of microwave photonics and optical communication, the low-loss and high-efficiency optical phase shifter has attracted intense attention in photonic integrated circuits. However, most of their applications are restricted to a particular band. Little is known about the characteristics of broadband. In this paper, an SiN-MoS2 integrated broadband racetrack phase shifter is demonstrated. The coupling region and the structure of the racetrack resonator are elaborately designed to improve the coupling efficiency at each resonance wavelength. The ionic liquid is introduced to form a capacitor structure. Then, the effective index of the hybrid waveguide can be efficiently tuned by adjusting the bias voltage. We achieve a phase shifter with a tunable range covering all the WDM bands and even up to 1900 nm. The highest phase tuning efficiency is measured to be 72.75 pm/V at 1860 nm, and the corresponding half-wave-voltage-length product is calculated as 0.0608 V·cm.

11.
Chem Rec ; 23(12): e202300293, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38010365

RESUMO

Cancer stands as a serious malady, posing substantial risks to human well-being and survival. This underscores the paramount necessity to explore and investigate novel antitumor medications. Nitrogen-containing compounds, especially those derived from natural sources, form a highly significant category of antitumor agents. Among these, antitumor agents with six-membered aromatic nitrogen heterocycles have consistently attracted the attention of chemists and pharmacologists. Accordingly, we present a comprehensive summary of synthetic strategies and clinical implications of these compounds in this review. This entails an in-depth analysis of synthesis pathways for pyridine, quinoline, pyrimidine, and quinazoline. Additionally, we explore the historical progression, targets, mechanisms of action, and clinical effectiveness of small molecule inhibitors possessing these structural features.


Assuntos
Antineoplásicos , Compostos Heterocíclicos , Humanos , Compostos Heterocíclicos/farmacologia , Compostos Heterocíclicos/química , Nitrogênio/química , Antineoplásicos/farmacologia , Antineoplásicos/química
12.
Phys Chem Chem Phys ; 25(8): 5913-5925, 2023 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-36779513

RESUMO

Traditional microwave absorbing materials (MAMs) have exposed more and more problems in multi-spectrum detection and a harsh service environment, which hinder their further application. Bionic materials and structures have attracted more and more attention from researchers in the field of stealth materials due to their excellent properties, such as high strength and high conductivity, along with easy access to scale adjustability and structural design. By introducing the concept of bionics into their structural design and material design, we can obtain highly efficient stealth materials with multiple properties. In addition, the concept of multispectral stealth is furthered by comparing the difference in the principle and methods of achievement between radar stealth and infrared stealth. This paper fundamentally summarizes the research status of bionic structure design ideas in stealth materials, analyzing the structure-activity relationship between the structural size effect and electromagnetic characteristics from low order to high order. Then, the design ideas and universal strategies of typical bionic structures are summarised and an idea for the integrated design of radar absorption compatible with infrared stealth is put forward. This will provide profound insights for the application of biomimetic stealth materials and the future development of intelligent-response and dynamically adjustable materials.

13.
Future Oncol ; 19(13): 947-959, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37199346

RESUMO

Aim: To explore whether immune checkpoint inhibitors (ICIs) increase the incidence of radiation-induced brain injury in lung cancer patients with brain metastases. Methods: According to whether they received ICIs within 6 months before and after cranial radiotherapy (CRT), all patients were divided into two groups: ICIs + CRT group and CRT + non-ICIs group. Results: The incidence of radiation necrosis (RN) in the CRT + ICIs group was 14.3%, while that in the CRT + non-ICIs group was 5.8% (p = 0.090). If ICIs were used within 3 months of CRT, there was statistical significance. A maximum diameter of brain metastasis >3.3 cm and cumulative radiation dose of metastatic lesions >75.7 Gy were risk factors for RN. Conclusion: ICIs could increase the risk of RN, especially when used within 3 months of CRT.


Assuntos
Lesões Encefálicas , Neoplasias Encefálicas , Neoplasias Pulmonares , Humanos , Estudos Retrospectivos , Neoplasias Pulmonares/patologia , Neoplasias Encefálicas/secundário , Imunoterapia/efeitos adversos
14.
Gene Ther ; 29(3-4): 115-126, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-33191399

RESUMO

Glioblastoma (GBM) is regarded as an incurable disease due to its poor prognosis and limited treatment options. Virotherapies were once utilized on cancers for their oncolytic effects. And they are being revived on GBM treatment, as accumulating evidence presents the immunogenic effects of virotherapies in remodeling immunosuppressive GBM microenvironment. In this review, we focus on the immune responses induced by oncolytic virotherapies and viral vectors in GBM. The current developments of GBM virotherapies are briefly summarized, followed by a detailed depiction of their immune response. Limitations and lessons inferred from earlier experiments and trials are discussed. Moreover, we highlight the importance of engaging the immune responses induced by virotherapies into the multidisciplinary management of GBM.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Terapia Viral Oncolítica , Vírus Oncolíticos , Neoplasias Encefálicas/terapia , Glioblastoma/genética , Glioblastoma/terapia , Humanos , Vírus Oncolíticos/genética , Microambiente Tumoral
15.
Opt Express ; 30(7): 11026-11035, 2022 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-35473055

RESUMO

A modified Frantz-Nodvik (F-N) equation and a simple one-dimensional unfolded slicing model for numerically simulating high-power Innoslab picosecond amplifier are developed for the first time. The anisotropic stimulated emission cross-section of laser crystal, the influence of the tilted optical path, the spatial overlap of the seed and pump laser, as well as the pump absorption saturation effect are considered. Based on the as-developed model, 4-, 6- and 8-pass schemes high-power Nd:YVO4 Innoslab picosecond amplifiers are designed with output powers of 76.2 W, 81.4 W, and 85.5 W, respectively. The experimental results agree well with that of numerical simulation, indicating that our model is a powerful tool and paves a new way for designing and optimizing high-power Innoslab picosecond laser amplifier.

16.
Opt Lett ; 47(5): 1254-1257, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-35230340

RESUMO

Gradient-based optimization combined with the adjoint method has been demonstrated to be an efficient way to design a nano-structure with a vast number of degrees of freedom. However, most inverse-designed photonic devices are applied as linear photonic devices. Here, we demonstrate the nonlinear optical response in inverse-designed integrated splitters fabricated on a SiN platform. The splitting ratio is tunable under different incident powers. The thermo-optical effect can be used as an effective approach for adjusting the nonlinear optical response threshold and modulation depth of the device. These promising results indicate the great potential of inverse-designed photonic devices in nonlinear optics and optical communications.

17.
Opt Lett ; 47(4): 949-952, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-35167566

RESUMO

We demonstrate a low-power, compact micro-ring phase shifter based on hybrid integration with atomically thin two-dimensional layered materials, and experimentally establish a low-loss silicon nitride platform. Using a wet transfer method, a large-area few-layer MoS2 film is hybrid integrated with a micro-ring phase shifter, leading to a tuning efficiency of 5.8 pm V-1 at a center wavelength of 1545.294 nm and a half-wave-voltage-length product as low as 0.09 V cm. Our device is designed to provide a hybrid-integration-based active phase modulation scheme for integrated optical communication networks with large-cross-section silicon nitride waveguides.

18.
Int J Mol Sci ; 23(19)2022 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-36233223

RESUMO

S-equol, a metabolite of soy isoflavone daidzein transformed by the gut microbiome, is the most biologically potent among all soy isoflavones and their metabolites. Soy isoflavones are phytoestrogens and exert their actions through estrogen receptor-ß. Epidemiological studies in East Asia, where soy isoflavones are regularly consumed, show that dietary isoflavone intake is inversely associated with cognitive decline and dementia; however, randomized controlled trials of soy isoflavones in Western countries did not generally show their cognitive benefit. The discrepant results may be attributed to S-equol production capability; after consuming soy isoflavones, 40-70% of East Asians produce S-equol, whereas 20-30% of Westerners do. Recent observational and clinical studies in Japan show that S-equol but not soy isoflavones is inversely associated with multiple vascular pathologies, contributing to cognitive impairment and dementia, including arterial stiffness and white matter lesion volume. S-equol has better permeability to the blood-brain barrier than soy isoflavones, although their affinity to estrogen receptor-ß is similar. S-equol is also the most potent antioxidant among all known soy isoflavones. Although S-equol is available as a dietary supplement, no long-term trials in humans have examined the effect of S-equol supplementation on arterial stiffness, cerebrovascular disease, cognitive decline, or dementia.


Assuntos
Disfunção Cognitiva , Demência , Microbioma Gastrointestinal , Isoflavonas , Antioxidantes , Disfunção Cognitiva/prevenção & controle , Demência/prevenção & controle , Equol/metabolismo , Receptor beta de Estrogênio , Humanos , Isoflavonas/metabolismo , Isoflavonas/farmacologia , Fitoestrógenos/metabolismo , Receptores de Estrogênio
19.
Childs Nerv Syst ; 37(7): 2399-2403, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33029729

RESUMO

Spinal neurocytoma (SN), although frequently reportedly as tumors of the central nervous system (CNS), are a distinct class of tumors, which can achieve a better prognosis following subtotal or gross total tumor resection. Nonetheless, even with the premise of successful treatment after tumor resection, poor prognosis after treatment due to the SN high proliferation index (typically known as atypical SN) have been reported. Over the past two decades, atypical SN was only reported in four pediatric cases, amidst the lingering controversy surrounding its postoperative adjuvant therapy. Thus, herein, we report a unique case of atypical SN with epidermal growth factor receptor (EGFR) amplification mutation in a 12-year-old boy. We, however, also highlighted the significance of radiotherapy and target therapy for patients with SN.


Assuntos
Neoplasias Encefálicas , Neurocitoma , Criança , Terapia Combinada , Receptores ErbB/genética , Humanos , Masculino , Mutação , Neurocitoma/diagnóstico por imagem , Neurocitoma/genética , Prognóstico
20.
Angew Chem Int Ed Engl ; 60(15): 8189-8197, 2021 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-33403799

RESUMO

Doping of polymeric semiconductors limits the miscibility between polymers and dopants. Although significant efforts have been devoted to enhancing miscibility through chemical modification, the electrical conductivities of n-doped polymeric semiconductors are usually below 10 S cm-1 . We report a different approach to overcome the miscibility issue by modulating the solution-state aggregates of conjugated polymers. We found that the solution-state aggregates of conjugated polymers not only changed with solvent and temperature but also changed with solution aging time. Modulating the solution-state polymer aggregates can directly influence their solid-state microstructures and miscibility with dopants. As a result, both high doping efficiency and high charge-carrier mobility were simultaneously obtained. The n-doped electrical conductivity of P(PzDPP-CT2) can be tuned up to 32.1 S cm-1 . This method can also be used to improve the doping efficiency of other polymer systems (e.g. N2200) with different aggregation tendencies and behaviors.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA