Publications by authors named "Keke He"

Many important information in medical research and clinical diagnosis are obtained from medical images. Among them, digital pathology images can provide detailed tissue structure and cellular information, which has become the gold standard for clinical tumor diagnosis. With the development of neural networks, computer-aided diagnosis presents the identification results of various cell nuclei to doctors, which facilitates the identification of cancerous regions.

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Covalent 2D magnets such as CrTe, which feature self-intercalated magnetic cations located between monolayers of transition-metal dichalcogenide material, offer a unique platform for controlling magnetic order and spin texture, enabling new potential applications for spintronic devices. Here, it is demonstrated that the unconventional anomalous Hall effect (AHE) in CrTe, characterized by additional humps and dips near the coercive field in AHE hysteresis, originates from an intrinsic mechanism dictated by the self-intercalation. This mechanism is distinctly different from previously proposed mechanisms such as topological Hall effect, or two-channel AHE arising from spatial inhomogeneities.

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Corneal integrity, transparency, and visual acuity are maintained by corneal epithelial cells (CECs), which are continuously renewed by limbal epithelial stem cells (LESCs). The limbal stem cell deficiency is associated with ocular diseases. This study aimed to develop a novel method to differentiate bone marrow mesenchymal stem cells (BM-MSCs) into LESC-like cells using a culture medium and paired box 6 (Pax6) transfection.

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Stacking of graphene with hexagonal boron nitride (h-BN) can dramatically modify its bands from their usual linear form, opening a series of narrow minigaps that are separated by wider minibands. While the resulting spectrum offers strong potential for use in functional (opto)electronic devices, a proper understanding of the dynamics of hot carriers in these bands is a prerequisite for such applications. In this work, we therefore apply a strategy of rapid electrical pulsing to drive carriers in graphene/h-BN heterostructures deep into the dissipative limit of strong electron-phonon coupling.

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Terahertz (THz) plasma oscillations represent a potential path to implement ultrafast electronic devices and circuits. Here, we present an approach to generate on-chip THz signals that relies on plasma-wave stabilization in nanoscale transistors with specific structural asymmetry. A hydrodynamic treatment shows how the transistor asymmetry supports plasma-wave amplification, giving rise to pronounced negative differential conductance (NDC).

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Evidence of robust spin-dependent transport in monolayer graphene, deposited on the (0001) surface of the antiferromagnetic (AFM)/magneto-electric oxide chromia (Cr O ), is provided. Measurements performed in the non-local spin-Hall geometry reveal a robust signal that is present at zero external magnetic field and which is significantly larger than any possible ohmic contribution. The spin-related signal persists well beyond the Néel temperature (≈307 K) that defines the transition between the AFM and paramagnetic states, remaining visible at the highest studied temperature of close to 450 K.

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Magnolia bark is an edible traditional Chinese medicine that has antibacterial activity against Staphylococcus aureus. In the present study, interactions between S. aureus DNA and raw magnolia bark (RMB) and ginger mix-fried magnolia bark (GMB) aqueous extracts were determined via spectroscopic methods.

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Vine tea (Ampelopsis grossedentata) has been approved as a new food ingredient in 2013. Both vine tea extract (VTE) and its active ingredient, 2R, 3R-Dihydromyricetin (DMY), showed good antibacterial activity. The mechanism of VTE and DMY against Staphylococcus aureus were evaluated by morphology observation, cell membrane and wall assay, protein assay, and DNA assay in this study.

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Background: Atopic dermatitis (AD) is a chronic, recurrent skin condition with recently increased incidence in younger children. AD development has been correlated with the skin microbiome, and Staphylococcus aureus enrichment causes significant increases in skin lesions.

Objective: Our objectives were to compare the microbial diversity of the cheek skin of children with or without AD aged 0-1 years in China, and to determine whether 4 types of skin-isolated bacteria could inhibit S.

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We explore the electrical characteristics of TiS nanowire field-effect transistor (FETs), over the wide temperature range from 3 to 350 K. These nanomaterials have a quasi-one-dimensional (1D) crystal structure and exhibit a gate-controlled metal-insulator transition (MIT) in their transfer curves. Their room-temperature mobility is ∼20-30 cm/(V s), 2 orders of magnitude smaller than predicted previously, a result that we explain quantitatively in terms of the influence of polar-optical phonon scattering in these materials.

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Background/aims: Healthy skin harbors numerous microbes known to maintain its health and prevent attacks from external pathogens. The influence of chemical preservatives commonly used in cosmetic products on facial resident flora remains poorly characterized. In this study, we aimed to investigate the antibacterial activity of five such preservatives on in vitro cultivated skin-resident bacteria.

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Carbon dioxide has attracted broad interest as a renewable C1 feedstock for efficient transformation into value-added organic chemicals; nevertheless, far less attention was paid to its stereochemically controlled catalytic fixation/conversion processes. Here, we report a new strategy for the selective synthesis of chiral carbamates from carbon dioxide via polycarbonate intermediates, which are formed by the desymmetric copolymerization of meso-epoxides using enantiopure dinuclear Co(III) catalyst systems with 99% enantioselectivity. Subsequent degradation reaction of the resultant polycarbonates with various primary or secondary amine nucleophiles can afford optically active carbamates, with the complete configuration retention of the two chiral carbon centers.

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By designing a polymer-film-coated asymmetric metallic slit structure that only contains one nanocavity side-coupled with a subwavelength plasmonic waveguide, the Fano resonance is realized in the experiment. The Fano resonance originates from the interference between the narrow resonant spectra of the radiative light from the nanocavity and the broad nonresonant spectra of the directly transmitted light from the slit. The lateral dimension of the asymmetric slit is only 825 nm.

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The development of efficient processes for CO2 transformation into useful products is a long-standing goal for chemists, since CO2 is an abundant, inexpensive and non-toxic renewable C1 resource. Here we describe the enantioselective copolymerization of 3,4-epoxytetrahydrofuran with CO2 mediated by biphenol-linked dinuclear cobalt complex, affording the corresponding polycarbonate with >99% carbonate linkages and excellent enantioselectivity (up to 99% enantiomeric excess). Notably, the resultant isotactic polycarbonate is a typical semicrystalline polymer, possessing a melting point of 271 °C.

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Article Synopsis
  • The study investigates the treatment and long-term outcomes of portal vein thrombosis (PVT) in patients who underwent partial splenic embolization (PSE) for hypersplenism due to cirrhotic portal hypertension.
  • Out of 145 patients treated, 11 developed PVT, with 5 receiving anticoagulant therapy; those treated had better outcomes, as none experienced variceal bleeding during follow-up.
  • The research highlights the importance of early detection and prompt anticoagulation to prevent severe complications associated with PVT following PSE.
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Introduction: Our objective was to trace and evaluate intracoronary transplanted mesenchymal stem cells (MSCs) labelled with superparamagnetic iron oxide (SPIO) by using magnetic resonance imaging (MRI) in a swine model of myocardial infarction (MI).

Methods: MSCs were transfected with a lentiviral vector carrying the gene encoding green fluorescent protein (GFP) and labelled in vitro with SPIO. At 2 weeks after MI, swine were randomized to intracoronary transplantation of dual-labelled MSCs (n=10), MSC-GFP (n=10), and saline (n=5).

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Background: This study was designed to investigate the effects of treatment with autologous mesenchymal stem cells (MSCs) by intracoronary transplantation on myocardial infarction (MI) in swine.

Methods: MSCs were transfected with a lentiviral vector carrying the gene encoding green fluorescent protein (GFP) and labeled in vitro with superparamagnetic iron oxide (SPIO). An acute MI (AMI) model was established by percutaneous balloon occlusion.

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Objective: To evaluate the technique, safety and clinical efficacy of transportal variceal sclerotherapy with n-butyl-2-cyanoacrylate (NBCA) for gastric fundal varices.

Methods: Twenty-one patients with gastric fundal varices confirmed by endoscopy were enrolled in this study. The causes of the gastric varices were cirrhosis caused by hepatitis virus B or C (n = 16) and hepatocellular carcinoma with portal venous obstruction (n = 5).

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Article Synopsis
  • The study aimed to assess how effective multi-detector row CT (MDCT) is for diagnosing gastric varices (GV) in patients with portal hypertension, comparing it to endoscopy and direct portography.
  • In a sample of 36 cirrhotic patients, MDCT successfully diagnosed submucosal GV and perigastric GV with high accuracy and strong agreement among three radiologists, showing a kappa value of 0.85 for submucosal and 1.0 for perigastric GV.
  • The results indicated that MDCT has a high sensitivity and specificity (over 80%) for identifying the veins involved in gastric varices, demonstrating its potential as a reliable imaging technique in the management of portal hypertension
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