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1.
Nano Lett ; 24(23): 6838-6843, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38825784

RESUMO

Moiré superlattices, constituted by two-dimensional materials, demonstrate a variety of strongly correlated and topological phenomena including correlated insulators, superconductivity, and integer/fractional Chern insulators. In the realm of topological nontrivial Chern insulators within specific moiré superlattices, previous studies usually observe a single Chern number at a given filling factor in a device. Here we present the observation of gate-tunable Chern numbers within the Chern insulator state of an ABC-stacked trilayer graphene/hexagonal boron nitride moiré superlattice device. Near quarter filling, the moiré superlattice exhibits spontaneous valley polarization and distinct ferromagnetism associated with the Chern insulator states over a range of the displacement field. Surprisingly we find a transition of the Chern number from C = 3 to 4 as the displacement field is increased. Our observation of gate-tunable correlated Chern insulators suggests new ways to control and manipulate topological states in a moiré superlattice device.

2.
Nat Mater ; 23(2): 189-195, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38177380

RESUMO

Electron superlattices allow the engineering of correlated and topological quantum phenomena. The recent emergence of moiré superlattices in two-dimensional heterostructures has led to exciting discoveries related to quantum phenomena. However, the requirement for the moiré pattern poses stringent limitations, and its potential cannot be switched on and off. Here, we demonstrate remote engineering and on/off switching of correlated states in bilayer graphene. Employing a remote Coulomb superlattice realized by localized electrons in twisted bilayer WS2, we impose a Coulomb superlattice in the bilayer graphene with period and strength determined by the twisted bilayer WS2. When the remote superlattice is turned off, the two-dimensional electron gas in the bilayer graphene is described by a Fermi liquid. When it is turned on, correlated insulating states at both integer and fractional filling factors emerge. This approach enables in situ control of correlated quantum phenomena in two-dimensional materials hosting a two-dimensional electron gas.

3.
Int J Mol Sci ; 24(21)2023 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-37958741

RESUMO

DNA synthesis catalyzed by DNA polymerase is essential for all life forms, and phosphodiester bond formation with phosphorus center inversion is a key step in this process. Herein, by using a single-selenium-atom-modified dNTP probe, we report a novel strategy to visualize the reaction stereochemistry and catalysis. We capture the before- and after-reaction states and provide explicit evidence of the center inversion and in-line attacking SN2 mechanism of DNA polymerization, while solving the diastereomer absolute configurations. Further, our kinetic and thermodynamic studies demonstrate that in the presence of Mg2+ ions (or Mn2+), the binding affinity (Km) and reaction selectivity (kcat/Km) of dGTPαSe-Rp were 51.1-fold (or 19.5-fold) stronger and 21.8-fold (or 11.3-fold) higher than those of dGTPαSe-Sp, respectively, indicating that the diastereomeric Se-Sp atom was quite disruptive of the binding and catalysis. Our findings reveal that the third metal ion is much more critical than the other two metal ions in both substrate recognition and bond formation, providing insights into how to better design the polymerase inhibitors and discover the therapeutics.


Assuntos
Selênio , DNA Polimerase Dirigida por DNA/metabolismo , Metais/farmacologia , Catálise , DNA , Íons , Cinética
4.
Sensors (Basel) ; 23(22)2023 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-38005529

RESUMO

A kind of full-function two-sided optical bench interferometer (OBI) is designed to meet the practical requirements of the Taiji Program for space gravitational wave detection. The main optical paths are arranged on the A-side for transmission and interference, and other optical paths and electronic devices are placed on the B-side. According to the design scheme, we successfully constructed two OBIs by using hydrogen-oxygen catalytic stress-free bonding technology. When the OBI is installed and adjusted, the position and Angle error of the interference beam are controlled within 30 µm and 50 µrad through the self-designed precision mechanical clamping mechanism and beam position measuring device. The built OBI was placed on the vibration isolation platform in the vacuum tank for the stability test. The test results show that the noise of the OBI is less than 10 pm/√Hz in the frequency band of 0.1 Hz to 1 Hz, which meets the noise budget requirements of the Taiji Pathfinder in the middle- and high-frequency band.

5.
Sensors (Basel) ; 23(19)2023 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-37836917

RESUMO

In space gravitational wave detection missions, a drag-free system is used to keep the test mass (TM) free-falling in an ultralow-noise environment. Ground verification experiments should be carried out to clarify the shielding and compensating capabilities of the system for multiple stray force noises. A hybrid apparatus was designed and analyzed based on the traditional torsion pendulum, and a technique for enhancing the sensitivity of the torsion pendulum system by employing the differential wavefront sensing (DWS) optical readout was proposed. The readout resolution experiment was then carried out on an optical bench that was designed and established. The results indicate that the angular resolution of the DWS signal in optical readout mode can reach the level of 10 nrad/Hz1/2 over the full measurement band. Compared with the autocollimator, the sensitivity of the torsional pendulum is noticeably improved, and the background noise is expected to reach 4.5 × 10-15 Nm/Hz1/2@10 mHz. This method could also be applied to future upgrades of similar systems.

6.
Nano Lett ; 23(15): 7023-7028, 2023 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-37474137

RESUMO

ABC-stacked trilayer graphene on boron nitride (ABC-TLG/hBN) moiré superlattices provides a tunable platform for exploring Wigner crystal states in which the electron correlation can be controlled by electric and magnetic fields. Here we report the observation of magnetic field-stabilized Wigner crystal states in a ABC-TLG/hBN. We show that correlated insulating states emerge at multiple fractional and integer fillings corresponding to ν = 1/3, 2/3, 1, 4/3, 5/3, and 2 electrons per moiré lattice site under a magnetic field. These correlated insulating states can be attributed to generalized Mott states for the integer fillings and generalized Wigner crystal states for the fractional fillings. The generalized Wigner crystal states are stabilized by a vertical magnetic field and are strongest at one magnetic flux quantum per three moiré superlattices. The ν = 2 insulating state persists up to 30 T, which can be described by a Mott-Hofstadter transition at a high magnetic field.

7.
BMC Oral Health ; 23(1): 63, 2023 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-36732711

RESUMO

BACKGROUND: Porphyromonas gingivalis (Pg) is one of the keystone pathogens involved in periodontitis. The present study aimed to observe the relationship among different infection forms of Pg, systemic inflammation, and acute myocardial infarction (AMI). METHODS: A total of 382 patients diagnosed with AMI and 78 patients without coronary heart disease (CHD) were included in the study. DNA from exfoliated oral cells, circulating cell-free DNA (cfDNA), and genomic DNA (gDNA) from blood samples were extracted. The qPCR method was employed to detect Pg infection. Clinical characteristics, inflammatory parameters, and severity of coronary artery lesions of the patients were analyzed and compared. RESULTS: Both the oral colonization and distant invasion of Pg correlated positively with systemic inflammation. Multivariate logistic regression analysis suggested that Pg positivity in gDNA was correlated with the risk of AMI [Model 1 (odds ratio (OR) = 1.917, 95% confidence interval (CI) 1.108-3.315), Model 2 (OR = 1.863, 95% CI 1.064-3.262), and Model 3 (OR = 1.853, 95% CI 1.042-3.295); p < 0.05]. Pg positivity in cfDNA and gDNA was related to the severity of coronary artery lesions (cfDNA-positive cases, adjusted OR = 1.577, p < 0.05; gDNA-positive cases, adjusted OR = 1.976, p < 0.01). CONCLUSIONS: The distant invasion and colonization of Pg were the risk factors of AMI. They also affected the severity of CHD, indicating that periodontitis severity and distant invasion of periodontal pathogens were related to CHD. The presence of Pg was likely able to drive systemic inflammation, suggesting that there was an inflammatory relationship between periodontitis and AMI.


Assuntos
Doença das Coronárias , Infarto do Miocárdio , Periodontite , Porphyromonas gingivalis , Humanos , Estudos Transversais , Inflamação , Infarto do Miocárdio/complicações , Periodontite/microbiologia
8.
Nature ; 614(7949): 688-693, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36813893

RESUMO

Thermally excited electrons and holes form a quantum-critical Dirac fluid in ultraclean graphene and their electrodynamic responses are described by a universal hydrodynamic theory. The hydrodynamic Dirac fluid can host intriguing collective excitations distinctively different from those in a Fermi liquid1-4. Here we report the observation of the hydrodynamic plasmon and energy wave in ultraclean graphene. We use the on-chip terahertz (THz) spectroscopy technique to measure the THz absorption spectra of a graphene microribbon as well as the propagation of the energy wave in graphene close to charge neutrality. We observe a prominent high-frequency hydrodynamic bipolar-plasmon resonance and a weaker low-frequency energy-wave resonance of the Dirac fluid in ultraclean graphene. The hydrodynamic bipolar plasmon is characterized by the antiphase oscillation of massless electrons and holes in graphene. The hydrodynamic energy wave is an electron-hole sound mode with both charge carriers oscillating in phase and moving together. The spatial-temporal imaging technique shows that the energy wave propagates at a characteristic speed of [Formula: see text] near the charge neutrality2-4. Our observations open new opportunities to explore collective hydrodynamic excitations in graphene systems.

9.
Cancers (Basel) ; 15(3)2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36765885

RESUMO

Cancer stem cells (CSCs) play significant roles in cancer development, drug resistance and cancer recurrence. In cancer treatments based on the CSC characteristics and inducing factors, MYC is a promising target for therapeutic molecules. Although it has been regarded as an undrugable target, its stability tightly regulated by the ubiquitin-proteasome system offers a new direction for molecule targeting and cancer treatment. Herein we report our discoveries in this research area, and we have found that deubiquitinase USP45 can directly bind with MYC, resulting in its deubiquitination and stabilization. Further, USP45 overexpressing can upregulate MYC, and this overexpressing can significantly enhance cancer development, cancer cell stemness and drug resistance. Interestingly, without enhancing cancer development, MYC silencing with shRNA can only suppress USP45-induced stemness and drug resistance. Moreover, we have identified that USP45 can be specifically bound and inhibited by a natural small molecule (α-mangostin), in turn significantly suppressing USP45-induced stemness and drug resistance. Since USP45 is significantly expressed in cervical tumors, we have discovered that the combination of α-mangostin and doxorubicin can significantly inhibit USP45-induced cervical tumorigenesis in an animal model. In general, on the basis of our USP45 discoveries on its MYC deubiquitination and α-mangostin inhibition, suppressing USP45 has opened a new window for suppressing cancer development, stemness and drug resistance.

10.
Stat Med ; 42(5): 656-675, 2023 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-36563324

RESUMO

In this paper we propose a new robust estimation of precision matrices for high-dimensional data when the number of variables is larger than the sample size. Different from the existing methods in literature, the proposed model combines the technique of modified Cholesky decomposition (MCD) with the robust generalized M-estimators. The MCD reparameterizes a precision matrix and transforms its estimation into solving a series of linear regressions, in which the commonly used robust techniques can be conveniently incorporated. Additionally, the proposed method adopts the model averaging idea to address the ordering issue in the MCD approach, resulting in an accurate estimation for precision matrices. Simulations and real data analysis are conducted to illustrate the merits of the proposed estimator.


Assuntos
Modelos Lineares , Humanos , Tamanho da Amostra , Causalidade
11.
Oral Dis ; 29(8): 3698-3706, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36321885

RESUMO

OBJECTIVES: To investigate oral infections in patients suffering in-stent restenosis (ISR) and non-ISR and analyze the possible correlation between the oral infection and triglyceride-glucose (TyG) index, a clinical surrogate indicator of insulin resistance (IR). MATERIALS AND METHODS: A cross-sectional design was used, in which 586 patients with acute coronary syndrome who underwent coronary angiography 6-24 months after coronary stent implantation were recruited. The modified total dental index (TDI) was used to evaluate the status of oral inflammation. RESULTS: In both univariate analyses, TDI scores [3 (1.5, 4.5) vs. 2.5 (1.5, 4.0), p < 0.01] and a multivariate regression model (OR = 1.202, 95% CI = 1.085-1.333, p < 0.01), the TDI significantly correlated with ISR. The TyG index was positively associated with ISR (OR = 1.766, 95% CI = 1.055-2.957, p < 0.05). Correlation analysis showed that TDI was positively correlated with TyG index (r = 0.190, p < 0.01). Using linear regression analysis, higher TDI scores were significantly associated with IR (95% CI = 0.029-0.063, p < 0.01). CONCLUSIONS: Oral infections and TyG index were independently and positively correlated with ISR in patients with acute coronary syndrome. Oral inflammatory burden assessed by TDI score was associated with IR.


Assuntos
Síndrome Coronariana Aguda , Reestenose Coronária , Humanos , Glucose , Reestenose Coronária/diagnóstico por imagem , Reestenose Coronária/etiologia , Triglicerídeos , Estudos Transversais , Fatores de Risco
12.
Ear Nose Throat J ; : 1455613221138214, 2022 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-36330830

RESUMO

Papillary thyroid carcinoma (PTC) is prone to regional lymph node metastasis, which is more common in central lymph nodes and lateral cervical lymph nodes, and retropharyngeal lymph node metastasis (RLNM) is extremely rare. A male with PTC presented with extensive cervical lymph node metastasis and the initial RLNM. After full evaluation by preoperative imaging examination, the patient underwent total thyroidectomy + left central lymph node dissection + left neck lymph node dissection (II III IV V) + left retropharyngeal tumor resection, and the postoperative recovery was good without recurrence long-term complications, and no local recurrence and metastasis were found during one-year follow-up.

13.
Dig Dis Sci ; 67(12): 5529-5539, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35314916

RESUMO

BACKGROUND: The NF-κB signaling cascade regulates immune response and is often dysregulated in tumor development. UBE2W is a novel type I ubiquitin-conjugating enzyme (E2) whose biological function is still unclear. AIMS: This study was designed to investigate whether UBE2W regulates NF-κB signaling pathway and is involved in the progression of experimental colitis. METHODS: At the cellular level, the effect of UBE2W on NF-κB transcriptional activity was measured using a dual-luciferase reporter assay. The influence of UBE2W on NF-κB pathway activation and the entry of p65 into the nucleus were determined by Western blot and immunofluorescence analyses, respectively. Moreover, the colitis model was established by administering 2.5% dextran sulfate sodium (DSS)/water to UBE2W overexpression, UBE2W-knockdown and control mice. Body weight, stool consistency, colon length and clinical severity were examined. Expression of pro-inflammatory cytokines and phosphorylation of p65 and IκB in the colon tissue were measured by qRT-PCR and Western blot, respectively. RESULTS: UBE2W inhibited TNFα-induced NF-κB transcription activity, attenuated IκB and p65 phosphorylation, downregulated TNFα and IL-8 expression and blocked the entry of p65 into the nucleus. In the DSS-induced colitis model, UBE2W-knockdown mice had increased weight loss, more serious diarrhea and mucosal injures compared with the control mice. Moreover, phosphorylation of IκB and p65 and the expression of pro-inflammatory mediators such as TNFα, IL-6 were significantly increased in UBE2W knockdown mice. However, these changes were completely reversed in UBE2W overexpression mice. CONCLUSIONS: The overexpression of UBE2W ameliorates the severity of DSS-induced colitis, which may be mediated by inhibiting the expression of pro-inflammatory mediators and activation of the NF-κB signaling pathway. These findings provide evidence that UBE2W might have potential therapeutic implications in IBD.


Assuntos
Colite , NF-kappa B , Camundongos , Animais , NF-kappa B/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , Sulfato de Dextrana/toxicidade , Modelos Animais de Doenças , Colite/patologia , Transdução de Sinais , Mediadores da Inflamação/metabolismo , Camundongos Endogâmicos C57BL , Enzimas de Conjugação de Ubiquitina/genética , Enzimas de Conjugação de Ubiquitina/metabolismo
14.
Nano Lett ; 22(1): 238-245, 2022 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-34978444

RESUMO

The flat bands resulting from moiré superlattices exhibit fascinating correlated electron phenomena such as correlated insulators, ( Nature 2018, 556 (7699), 80-84), ( Nature Physics 2019, 15 (3), 237) superconductivity, ( Nature 2018, 556 (7699), 43-50), ( Nature 2019, 572 (7768), 215-219) and orbital magnetism. ( Science 2019, 365 (6453), 605-608), ( Nature 2020, 579 (7797), 56-61), ( Science 2020, 367 (6480), 900-903) Such magnetism has been observed only at particular integer multiples of n0, the density corresponding to one electron per moiré superlattice unit cell. Here, we report the experimental observation of ferromagnetism at noninteger filling (NIF) of a flat Chern band in a ABC-TLG/hBN moiré superlattice. This state exhibits prominent ferromagnetic hysteresis behavior with large anomalous Hall resistivity in a broad region of densities centered in the valence miniband at n = -2.3n0. We observe that, not only the magnitude of the anomalous Hall signal, but also the sign of the hysteretic ferromagnetic response can be modulated by tuning the carrier density and displacement field. Rotating the sample in a fixed magnetic field demonstrates that the ferromagnetism is highly anisotropic and likely purely orbital in character.

15.
J Clin Med ; 12(1)2022 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-36615114

RESUMO

Background: Several recent studies have reported the relationship between atherosclerosis and gut microbial imbalance. Small intestinal bacterial overgrowth (SIBO) is one of the most common forms of gut microbiota imbalance, and studies have shown that SIBO plays an important role in human health. However, the relationship between SIBO and subclinical atheromatous plaques remains unclear. The aim of this study was to investigate the frequency of subclinical atheromatous plaques in patients with SIBO and to explore the association between these two conditions. Methods: A total of 411 eligible subjects were included in this study. The lactulose hydrogen-methane breath test was used to diagnose SIBO, and ultrasound examinations of the carotid, abdominal aorta and lower extremity arteries were performed in all subjects to assess the presence of plaques. Results: Plaques were more common in the SIBO-positive group than in the SIBO-negative group (abdominal aorta, 74.2% vs. 38.8%, p < 0.01; carotid arteries, 71.7% vs. 52.3, p < 0.01; lower extremity arteries, 73.4% vs. 57.6%, p < 0.01). After adjusting for traditional confounders, compared to the SIBO-negative population, the SIBO-positive population had, respectively, OR = 4.18 (95% CI = 2.56−6.80, p < 0.001), OR = 1.93 (95% CI = 1.23−3.02, p = 0.004), OR = 1.81 (95% CI = 1.14−2.88, p = 0.011) and OR = 5.42 (95% CI = 2.78−10.58, p < 0.001) for abdominal, carotid, lower extremity and any-territory plaque presence. Conclusion: SIBO was found to be associated with subclinical atheromatous plaques, and the mechanism of this association warrants further exploration.

16.
Am J Transl Res ; 13(7): 7632-7640, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34377240

RESUMO

OBJECTIVE: There is uncertainty of the benefit of percutaneous coronary intervention (PCI) for chronic coronary total occlusion (CTO). The study aimed to investigate potential long-term changes in ischemic burden in patients with CTO after PCI. METHODS: Patients who underwent CTO PCI with available records of 15O-H2O positron emission tomography within 3 months prior to and at least 6 months after successful CTO PCI were retrospectively included. Data on perfusion defect size, hyperemic myocardial blood flow (MBF), and coronary flow reserve (CFR) within the CTO area before and after CTO PCI were extracted and compared for evaluating ischemic burden. The comparisons were also performed after stratifying by baseline perfusion defect sizes. RESULTS: A total of 74 eligible patients were included with an average age of 62.0±7.5 years. Significant decrease in perfusion defect size (3 (2-4) versus 1 (0-2) segments, P<0.001) and significant increase in hyperemic MBF (1.32±0.39 versus 2.27±0.52 mL/min/g, P<0.001) and CFR (1.72±0.47 versus 2.73±0.73, P<0.001) were observed after CTO PCI when compared to that at baseline. When stratifying by baseline perfusion defect size, no significant differences were observed between groups in changes of hyperemic MBF (P=0.301) and CFR (P=0.850), but patients with larger perfusion defect size exhibited greater reduction in perfusion defect size (P<0.001). CONCLUSIONS: CTO PCI relieved ischemic burden for at least 6 months, and patients with larger baseline perfusion defect size might benefit more from CTO PCI in terms of ischemic burden.

17.
Cell Biol Int ; 45(11): 2294-2303, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34296787

RESUMO

This study aimed to investigate the functions of miR-214-3p in diabetic neuropathic rodents. The diabetic neuropathy was induced by intraperitoneal injection of streptozotocin (STZ) in rats, and miR-214-3p was delivered via tail vein injection of lentivirus. Hot or cold stimulus tests demonstrated that STZ induced thermal hyperalgesia. Neurophysiological measurements revealed that motor and sensory nerve conduction velocity and nerve blood flow were decreased in diabetic neuropathic rats. However, the STZ-induced hyperalgesia, and reduced nerve conduction velocity and nerve blood flow were all significantly reversed by miR-214-3p administration. HE staining, TUNEL, ELISA, and immunoblotting demonstrated that STZ led to obvious pathological lesion, cell apoptosis, and inflammation in dorsal root ganglion (DRG), evidenced by altered levels of apoptosis-related protein molecules and inflammatory factors, and activation of Toll-like receptor 4 (TLR4)/myeloid differentiation primary response gene 88/nuclear factor kappa B signaling. The pathological alterations in diabetic neuropathic rats in DRG were significantly ameliorated by miR-214-3p application. In addition, sodium channel protein type 3 subunit alpha isoform 1 (Nav1.3) and TLR4 were identified as targets of miR-214-3p via dual-luciferase reporter assay. MiR-214-3p may play its roles by downregulating Nav1.3 and TLR4. In summary, miR-214-3p alleviated diabetes-induced nerve injury, and pathological lesion, cell apoptosis, and inflammation in DRG by regulating Nav1.3 and TLR4 in STZ-induced rats. These findings may provide novel therapeutic targets for clinical treatment of diabetic neuropathy.


Assuntos
Neuropatias Diabéticas/genética , MicroRNAs/genética , Canal de Sódio Disparado por Voltagem NAV1.3/metabolismo , Receptor 4 Toll-Like/metabolismo , Animais , Apoptose , Diabetes Mellitus Experimental/genética , Neuropatias Diabéticas/fisiopatologia , Modelos Animais de Doenças , Gânglios Espinais/metabolismo , Hiperalgesia/fisiopatologia , Inflamação/metabolismo , Masculino , MicroRNAs/metabolismo , Canal de Sódio Disparado por Voltagem NAV1.3/genética , NF-kappa B/metabolismo , Ratos , Ratos Sprague-Dawley , Transdução de Sinais , Estreptozocina/farmacologia , Receptor 4 Toll-Like/genética
18.
Nature ; 594(7864): 517-521, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34163053

RESUMO

Fizeau demonstrated in 1850 that the speed of light can be modified when it is propagating in moving media1. However, such control of the light speed has not been achieved efficiently with a fast-moving electron media by passing an electrical current. Because the strong electromagnetic coupling between the electron and light leads to the collective excitation of plasmon polaritons, it is hypothesized that Fizeau drag in electron flow systems manifests as a plasmonic Doppler effect. Experimental observation of the plasmonic Doppler effect in electronic systems has been challenge because the plasmon propagation speed is much faster than the electron drift velocity in conventional noble metals. Here we report direct observation of Fizeau drag of plasmon polaritons in strongly biased monolayer graphene by exploiting the high electron mobility and the slow plasmon propagation of massless Dirac electrons. The large bias current in graphene creates a fast-drifting Dirac electron medium hosting the plasmon polariton. This results in non-reciprocal plasmon propagation, where plasmons moving with the drifting electron media propagate at an enhanced speed. We measure the Doppler-shifted plasmon wavelength using cryogenic near-field infrared nanoscopy, which directly images the plasmon polariton mode in the biased graphene at low temperature. We observe a plasmon wavelength difference of up to 3.6 per cent between a plasmon moving with and a plasmon moving against the drifting electron media. Our findings on the plasmonic Doppler effect provide opportunities for electrical control of non-reciprocal surface plasmon polaritons in non-equilibrium systems.

19.
J Biophotonics ; 14(6): e202000444, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33583150

RESUMO

Fourier ptychographic microscopy is a promising imaging technique which can circumvent the space-bandwidth product of the system and achieve a reconstruction result with wide field-of-view (FOV), high-resolution and quantitative phase information. However, traditional iterative-based methods typically require multiple times to get convergence, and due to the wave vector deviation in different areas, the millimeter-level full-FOV cannot be well reconstructed once and typically required to be separated into several portions with sufficient overlaps and reconstructed separately, which makes traditional methods suffer from long reconstruction time for a large-FOV (of the order of minutes) and limits the application in real-time large-FOV monitoring of live sample in vitro. Here we propose a novel deep-learning based method called DFNN which can be used in place of traditional iterative-based methods to increase the quality of single large-FOV reconstruction and reducing the processing time from 167.5 to 0.1125 second. In addition, we demonstrate that by training based on the simulation dataset with high-entropy property (Opt. Express 28, 24 152 [2020]), DFNN could has fine generalizability and little dependence on the morphological features of samples. The superior robustness of DFNN against noise is also demonstrated in both simulation and experiment. Furthermore, our model shows more robustness against the wave vector deviation. Therefore, we could achieve better results at the edge areas of a single large-FOV reconstruction. Our method demonstrates a promising way to perform real-time single large-FOV reconstructions and provides further possibilities for real-time large-FOV monitoring of live samples with sub-cellular resolution.


Assuntos
Processamento de Imagem Assistida por Computador , Redes Neurais de Computação , Microscopia
20.
J Int Med Res ; 48(12): 300060520978122, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33327816

RESUMO

OBJECTIVE: To explore specific flora in mouse models of non-alcoholic steatohepatitis (NASH) to improve NASH diagnostic protocols. METHODS: Sixty mice were divided into normal diet (ND, 20 mice) and high-fat/high-sugar diet (HFSD) groups (40 mice). After 8 weeks of feeding, 10 mice in the ND group and 20 mice in the HFSD group were sacrificed to create the short-term ND and non-alcoholic fatty liver (NAFL) groups, respectively. After 16 weeks of feeding, the remaining mice were sacrificed to create the long-term ND and NASH groups, respectively. We then examined fecal flora, serum biochemical indices, and lipopolysaccharide and tumor necrosis factor-α levels and analyzed liver tissue. RESULTS: The relative abundance of Lactobacillus, Desulfovibrio, Ruminiclostridium 9, and Turicibacter differed between NASH and NAFL mice, and the areas under the receiver operating characteristic curve of the four genera for diagnosing NASH were 0.705, 0.734, 0.737, and 0.937. The non-alcoholic fatty liver disease activity score was positively correlated with the relative abundance of Desulfovibrio (r = 0.353), Ruminiclostridium 9 (r = 0.431), and Turicibacter (r = 0.688). CONCLUSIONS: The relative abundance of Lactobacillus, Desulfovibrio, Ruminiclostridium, and Turicibacter may help distinguish NASH from NAFL.


Assuntos
Microbioma Gastrointestinal , Hepatopatia Gordurosa não Alcoólica , Animais , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Fígado , Camundongos , Hepatopatia Gordurosa não Alcoólica/diagnóstico , Hepatopatia Gordurosa não Alcoólica/microbiologia
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