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Depositing diamond-like carbon (DLC) film is considered to be more promising for surface modification of microparticles. The development of reliable and precise measurement techniques for DLC coatings on microparticles is crucial for advancing research in this field. This paper introduces a methodological approach for quantifying the thickness of the film on microparticles. The thickness of the film is obtained by establishing the quantitative relationship between the energy lost when electrons pass through the film and the thickness of the film. The proposed method allows for the estimation of film thickness by assessing solely the elemental abundance on the particle surfaces.
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Construction of a vertically aligned and densely interconnected ordered 3D filler framework in a polymer matrix is a challenge to attain significant thermal conductivity (TC) enhancement efficiency. Fortunately, many biomaterials with unique microstructures can be found in nature. With inspiration from wood, artificial composites can be rationally designed to achieve desired properties. Herein, the authors report a facile and effective approach to fabricate anisotropic polymer composites by biotemplate ceramization technology and subsequent vacuum impregnation of epoxy resin. The hierarchical microstructure of wood is perfectly replicated in the cellular biomass derived SiC (bioSiC) framework by carbothermal reduction. Owing to the anisotropic architecture of bioSiC, the epoxy composite with vertically aligned dense SiC microchannels shows interesting properties, including a high TC (10.27 W m-1 K-1 ), a significant enhancement efficiency (259 per 1 vol% loading), an outstanding anisotropic TC ratio (5.77), an extremely low coefficient of linear thermal expansion (12.23 ppm K-1 ), a high flexural strength (222 MPa), and an excellent flame resistance. These results demonstrate that this approach is expected to open a new avenue for design and preparation of high performance thermal management materials to address the heat dissipation of modern electronics.
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Polímeros , Madera , Anisotropía , Electrónica , Conductividad TérmicaRESUMEN
Nickel-cobalt borides (denoted as NCBs) have been considered as a promising candidate for aqueous supercapacitors due to their high capacitive performances. However, most reported NCBs are amorphous that results in slow electron transfer and even structure collapse during cycling. In this work, a nanocrystallized NCBs-based supercapacitor is successfully designed via a facile and practical microimpinging stream reactor (MISR) technique, composed of a nanocrystallized NCB core to facilitate the charge transfer, and a tightly contacted Ni-Co borates/metaborates (NCBi ) shell which is helpful for OH- adsorption. These merits endow NCB@NCBi a large specific capacity of 966 C g-1 (capacitance of 2415 F g-1 ) at 1 A g-1 and good rate capability (633.2 C g-1 at 30 A g-1 ), as well as a very high energy density of 74.3 Wh kg-1 in an asymmetric supercapacitor device. More interestingly, it is found that a gradual in situ conversion of core NCBs to nanocrystallized Ni-Co (oxy)-hydroxides inwardly takes place during the cycles, which continuously offers large specific capacity due to more electron transfer in the redox reaction processes. Meanwhile, the electron deficient state of boron in metal-borates shells can make it easier to accept electrons and thus promote ionic conduction.
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An amendment to this paper has been published and can be accessed via a link at the top of the paper.
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BACKGROUND AND OBJECTIVE: Medical image segmentation plays an important role in many clinical applications such as disease diagnosis, surgery planning, and computer-assisted therapy. However, it is a very challenging task due to variant images qualities, complex shapes of objects, and the existence of outliers. Recently, researchers have presented deep learning methods to segment medical images. However, these methods often use the high-level features of the convolutional neural network directly or the high-level features combined with the shallow features, thus ignoring the role of the global context features for the segmentation task. Consequently, they have limited capability on extensive medical segmentation tasks. The purpose of this work is to devise a neural network with global context feature information for accomplishing medical image segmentation of different tasks. METHODS: The proposed global context network (GC-Net) consists of two components; feature encoding and decoding modules. We use multiple convolutions and batch normalization layers in the encoding module. On the other hand, the decoding module is formed by a proposed global context attention (GCA) block and squeeze and excitation pyramid pooling (SEPP) block. The GCA module connects low-level and high-level features to produce more representative features, while the SEPP module increases the size of the receptive field and the ability of multi-scale feature fusion. Moreover, a weighted cross entropy loss is designed to better balance the segmented and non-segmented regions. RESULTS: The proposed GC-Net is validated on three publicly available datasets and one local dataset. The tested medical segmentation tasks include segmentation of intracranial blood vessel, retinal vessels, cell contours, and lung. Experiments demonstrate that, our network outperforms state-of-the-art methods concerning several commonly used evaluation metrics. CONCLUSION: Medical segmentation of different tasks can be accurately and effectively achieved by devising a deep convolutional neural network with a global context attention mechanism.
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Procesamiento de Imagen Asistido por Computador/métodos , Redes Neurales de la Computación , AlgoritmosRESUMEN
The anticancer agent indisulam inhibits cell proliferation by causing degradation of RBM39, an essential mRNA splicing factor. Indisulam promotes an interaction between RBM39 and the DCAF15 E3 ligase substrate receptor, leading to RBM39 ubiquitination and proteasome-mediated degradation. To delineate the precise mechanism by which indisulam mediates the DCAF15-RBM39 interaction, we solved the DCAF15-DDB1-DDA1-indisulam-RBM39(RRM2) complex structure to a resolution of 2.3 Å. DCAF15 has a distinct topology that embraces the RBM39(RRM2) domain largely via non-polar interactions, and indisulam binds between DCAF15 and RBM39(RRM2), coordinating additional interactions between the two proteins. Studies with RBM39 point mutants and indisulam analogs validated the structural model and defined the RBM39 α-helical degron motif. The degron is found only in RBM23 and RBM39, and only these proteins were detectably downregulated in indisulam-treated HCT116 cells. This work further explains how indisulam induces RBM39 degradation and defines the challenge of harnessing DCAF15 to degrade additional targets.
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Antineoplásicos/farmacología , Péptidos y Proteínas de Señalización Intracelular/química , Proteínas de Unión al ARN/química , Sulfonamidas/farmacología , Secuencias de Aminoácidos , Calorimetría , Clonación Molecular , Fluorometría , Células HCT116 , Células HEK293 , Humanos , Procesamiento de Imagen Asistido por Computador , Péptidos y Proteínas de Señalización Intracelular/genética , Cinética , Proteínas Nucleares/metabolismo , Péptidos/química , Mutación Puntual , Unión Proteica , Estructura Cuaternaria de Proteína , Estructura Secundaria de Proteína , Proteoma , ARN Interferente Pequeño/metabolismo , Proteínas de Unión al ARN/genética , Ubiquitina-Proteína Ligasas/metabolismoRESUMEN
Lipid rafts and associated membrane proteins (flotillin, caveolin) play important roles in cell signaling and sperm fertilization while heat shock proteins (Hsp) ensure properly protein folding to fulfill their physiological functions. The markedly reduced fertility in thawed sperm after cryopreservation could result from disrupted membrane lipid rafts and these proteins. To explore the effect of sperm cryopreservation on lipid rafts and heat shock proteins, we compared lipid raft integrity, and the expression levels of lipid raft associated proteins (Flot-1, Flot-2, Cav-1) as well as heat shock proteins (Hsp90, Hsp70) in fresh and thawed sperm cryopreserved under different scenarios in yellow catfish. We found higher lipid raft integrity, higher protein expression levels of Flot-1, Flot-2, Cav-1, Hsp90, and Hsp70 in fresh sperm samples than in thawed sperm samples, in thawed sperm samples cryopreserved with optimal cooling rate than those cryopreserved with sub-optimal cooling rate, and in thawed sperm samples cryopreserved with extenders supplemented with cholesterol than those supplemented with methyl-ß-cyclodextrin (for cholesterol removal). Our findings indicate that lipid raft integrity, and expression levels of Flot-1, Flot-2, Cav-1, Hsp90, and Hsp70 are clearly associated with sperm quality, and together they may play a cumulative role in reduced fertility associated with thawed sperm in aquatic species.
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Caveolinas/metabolismo , Criopreservación/métodos , Proteínas HSP70 de Choque Térmico/metabolismo , Proteínas HSP90 de Choque Térmico/metabolismo , Microdominios de Membrana/metabolismo , Proteínas de la Membrana/metabolismo , Animales , Bagres/fisiología , Colesterol/farmacología , Masculino , Análisis de Semen , Transducción de Señal , Motilidad Espermática/efectos de los fármacos , Espermatozoides/efectos de los fármacosRESUMEN
Carbon aerogels with excellent conductive characteristics and high specific capacitance have attracted more and more interests for next-generation energy storage applications. Three-dimensional interconnected Mn2O3/carbon aerogel supercapacitor electrodes are prepared by a novel doping method using MnO2 coordinated by N, N-dimethylmethanamide (DMF). The coordinative MnO2 (DMF/MnO2) plays a key role in the sol-gel process of resorcinol and formaldehyde. The doped carbon aerogels exhibits a high specific surface area of 859â¯m2â¯g-1 and a good pore-size distribution of 10-15â¯nm. All of the doped carbon aerogels exhibit higher specific capacitance than pure carbon aerogels, and the highest specific capacitance (170â¯Fâ¯g-1), at current density of 1.0â¯Aâ¯g-1, is obtained in Mn-CA-5% when 5â¯mol% DMF/MnO2 is added to the precursor solution. The specific capacitance is as high as 100â¯Fâ¯g-1, at current density of 10.0â¯Aâ¯g-1, and 97% of initial capacitance is retained over 1000 cycles at a current density of 5.0â¯Aâ¯g-1. The doped carbon aerogels exhibits a high coulombic efficiency (up to 99.8%) and a good rate capability. The corresponding result is due to the novel doping method of DMF/MnO2 addition.
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Environmental problems caused by metal ions have caused widespread concern in recent years. In this work, carbon aerogels (CAs) adsorbing different metal ions were prepared. The adsorption performance and kinetics of metal ions (Cu(II), Cr(VI), and Fe(III)) on carbon aerogels were systematically investigated. The results indicated that the maximum adsorption capacity of Cu(II) was 424 mg·g-1 in 600 mg·L-1 copper solution. Adsorption performances of Cu(II), Cr(VI), and Fe(III) on CAs well fitted with a pseudo-second-order kinetic model. The structures and morphologies of metal-containing samples were characterized by scanning electron micrographs (SEM), Energy Dispersive Spectrometer (EDS), transmission electron microscope (TEM), and X-ray diffraction (XRD). The results demonstrated that the texture and electrochemical performance of CAs adsorbing metal ions exhibited a clear change. The specific surface area of CAs for adsorbing copper ions was 450 m²·g-1 and they showed a small average pore diameter (7.16 nm). Furthermore, CAs adsorbing metals could be used for the super capacitor. The specific capacitance of CAs adsorbing copper ions could reach 255 F·g-1 at a current density of 1.0 A·g-1. The CA-Cu electrode materials exhibited excellent reversibility with a cycling efficiency of 97% after 5000 cycles.
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Pharmacological targeting of breast cancer stem cells (CSCs) is highly promising for the treatment of breast cancer, as the small population of CSCs is responsible for tumor initiation, progression, recurrence and chemo-resistance. Celecoxib is one of the most commonly used non-steroidal anti-inflammatory drugs (NSAIDs), which have chemo-preventive activity against cancers, including breast cancer and colorectal cancer. However, the mechanisms by which NSAIDs exert its cancer prevention effects have yet been completely understood. In the present study, we investigated for the first time the effect of celecoxib on breast CSCs inhibition and its potential molecular mechanisms. Our results demonstrated that celecoxib suppresses CSC self-renewal, sensitizes chemo-resistance, inhibits epithelial to mesenchymal transition (EMT), and attenuates metastasis and tumorigenesis. Further exploring the underlying mechanism revealed that celecoxib targets breast CSCs by inhibiting the synthesis of prostaglandin E2 and down-regulating the Wnt pathway activity. Our findings suggest that celecoxib, by targeting CSCs, may be used as an adjuvant chemotherapy drug to improve breast cancer treatment outcomes.
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At present, conducting standard lightning impulse (LI) tests in the field for gas-insulated switchgear (GIS) equipment is difficult because of the high capacitance of the test equipment and large circuit inductance of traditional impulse devices, which leads to a wavefront time T(f) ≥ 2.5 µs. A novel fully enclosed, compact standard LI generator for testing ultra-high-voltage-class GIS equipment with high capacitance is presented to solve the problem of T(f) exceeding the standard during LI voltage tests for actual large-sized equipment. The impulse generator is installed in a metal vessel filled with SF6 or SF6/N2 gas mixture at a pressure of 0.3-0.5 MPa, providing a more compact structure and a lower series inductance. A newly developed conical voltage sensor is used to accurately measure the output voltage waveform. Two test modes (via bushing docking and direct docking) for the GIS test based on the impulse generator are introduced. Calculation results show that the impulse generator can generate an LI test waveform following the present IEC standard for the test of equipment with capacitance >10,000 pF.
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OBJECTIVE: To study the clinical value and operation skills of nasal endoscopy-assisted bulboprostatic anastomosis in the treatment of posterior urethral stricture. METHODS: Between January 2012 and November 2014, we performed nasal endoscopy-assisted bulboprostatic anastomosis for 12 male patients with posterior urethral stricture. We recorded the operation time, blood loss, exposure of operation visual field, and success rate of anastomosis and summarized the operation skills. RESULTS: Eight of the patients experienced first-stage recovery. Two underwent a urethral dilation at 3 months postoperatively, 1 received 10 urethral dilations within 5 months after surgery, and 1 underwent internal urethrotomy after failure in urethral dilation, but all the 4 cases were cured. CONCLUSION: Nasal endoscopy can significantly improve the operation field exposure, elevate the precision, reduce the difficulty, and enhance the efficiency of bulboprostatic anastomosis in the treatment of posterior urethral stricture.
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Anastomosis Quirúrgica , Endoscopía , Estrechez Uretral/cirugía , Humanos , Masculino , Tempo Operativo , Periodo Posoperatorio , Uretra/patología , Uretra/cirugíaRESUMEN
Hepatitis C virus (HCV) is a major global public health problem. While the current standard of care, a direct-acting antiviral (DAA) protease inhibitor taken in combination with pegylated interferon and ribavirin, represents a major advancement in recent years, an unmet medical need still exists for treatment modalities that improve upon both efficacy and tolerability. Toward those ends, much effort has continued to focus on the discovery of new DAAs, with the ultimate goal to provide interferon-free combinations. The RNA-dependent RNA polymerase enzyme NS5B represents one such DAA therapeutic target for inhibition that has attracted much interest over the past decade. Herein, we report the discovery and optimization of a novel series of inhibitors of HCV NS5B, through the use of structure-based design applied to a fragment-derived starting point. Issues of potency, pharmacokinetics, and early safety were addressed in order to provide a clinical candidate in fluoropyridone 19.
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Antivirales/farmacología , Inhibidores Enzimáticos/farmacología , ARN Polimerasa Dependiente del ARN/antagonistas & inhibidores , Proteínas no Estructurales Virales/antagonistas & inhibidores , Animales , Antivirales/química , Antivirales/farmacocinética , Área Bajo la Curva , Línea Celular Tumoral , Perros , Descubrimiento de Drogas/métodos , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacocinética , Hepacivirus/efectos de los fármacos , Hepacivirus/enzimología , Hepacivirus/fisiología , Hepatitis C/prevención & control , Hepatitis C/virología , Interacciones Huésped-Patógeno/genética , Humanos , Modelos Moleculares , Terapia Molecular Dirigida/métodos , Unión Proteica , Estructura Terciaria de Proteína , Piridonas/síntesis química , Piridonas/farmacocinética , Piridonas/farmacología , ARN Polimerasa Dependiente del ARN/química , ARN Polimerasa Dependiente del ARN/metabolismo , Ratas , Relación Estructura-Actividad , Proteínas no Estructurales Virales/química , Proteínas no Estructurales Virales/metabolismoRESUMEN
Based on the characteristic of high speed line scanning for CCD in transient spectrum detection, a method of transient spectrum detection with array CCD is presented. The high speed line scanning with array CCD was realized by changing the mode of charge transfer. In order to explore the feasibility of this method, a fast detection system of single point based on linear CCD was designed and fabricated. Seven different LED pulses were measured when the system worked at fast detection mode of single point and normal mode respectively. The results demonstrate that the method of fast detection of single point based on linear CCD is feasible, and the rate of single point detection reaches up to 20 MHz. Thus, in theory, it was proved that transient spectrum detection with array CCD by changing the mode of charge transfer is also feasible.
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China has been implementing regional collaborative medical service (also known as e-health) for >5 years, but is still facing the challenges of bridging different community health information systems (CHISs). The fact that different communities have different systems makes it difficult to share information and data between different CHISs. To explore a solution for addressing this problem, we constructed a demonstration CHIS in Beijing's Dongcheng District. This system is based on the Software-as-a-Service model, in which a central data center is used to store users' health records and to provide different services. This system provides a comprehensive platform combining disease prevention, health protection, medical care, rehabilitation, health education, and family planning. In this article, we first show the challenge of implementing e-health-oriented CHIS in China, then we briefly introduce our solution, and finally we share our experience learned from the modern CHIS implementation practice.
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Sistemas de Información/normas , Sistemas de Registros Médicos Computarizados/normas , Integración de Sistemas , Telemedicina , China , HumanosRESUMEN
This article presents the design and applications of a rescue terminal with positioning, vital signs sensing, and communicating function for special environment. The terminal provides three-dimensional positioning functionality via China's Beidou 1 Navigation Satellite (BD1) System and can collect users' vital signs with a set of wireless sensors. A controller of the terminal is in charge of processing data collected from the wireless sensors and communicating with the monitoring platform. With features such as small sizing, low power consumption, and accurate positioning, this terminal is very helpful in special circumstances such as disaster relief, dangerous outdoor sports and adventure monitoring, and antiterrorism activities.
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Desarrollo de Programa , Tecnología de Sensores Remotos/métodos , Comunicaciones por Satélite , Telemedicina/métodos , Signos Vitales , Planificación en Desastres , Sistemas de Comunicación en Hospital , Humanos , Evaluación de Programas y Proyectos de Salud , Sistemas de Socorro , Tecnología de Sensores Remotos/instrumentación , Telemedicina/instrumentación , TerrorismoRESUMEN
Based on the spectral characteristic of the detonation temperature, the present paper presents a measurement system of transient multi-wavelength pyrometry with the theory of multi-wavelength thermometry. The FPGA was applied as the hardware developing platform and the high-speed linear CCD was utilized. Each module was controlled by FPGA to achieve the process of real-time data acquisition, storage and transmission. Using the multiple regression analysis method, the dynamic spectral waveforms were calculated. The two laser spectral lines, 630 and 532 nm, were used to calibrate the corresponding pixel sequence numbers and the No. 175 and No. 270 were confirmed. In this paper, the halide tungsten light was measured. The results show that the system can sample continuous spectrum signal at several different times; the CCD can stably work with 40 MHz clock and the frame scanning frequency can achieve 73 kHz.
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Tendón Calcáneo/irrigación sanguínea , Venodisección , Estomatitis Aftosa/terapia , Niño , Preescolar , Femenino , Humanos , Lactante , MasculinoRESUMEN
Although China started to study and implement telemedicine much later than other advanced countries, telemedicine is developing very fast in this country. Research on telemedicine is also getting popular, and more and more teleconsultant systems are being carried out. For the purpose of assessing the development of telemedicine in China over these past 50 years, we conducted a study of three elements, namely (1) teleconsultations, (2) academic activities, and (3) education. We carried out our study from three perspectives: the teleconsultant, telemedicine academic activities, and telemedicine education. In this article, we also show our recent achievement in telemedicine based on the Regional Collaborative Medical Service.
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Difusión de Innovaciones , Informática Médica , Telemedicina/organización & administración , China , Sistemas de Computación , Educación a Distancia/organización & administración , Educación Médica/organización & administración , Predicción , Planificación en Salud/organización & administración , Humanos , Informática Médica/educación , Informática Médica/instrumentación , Informática Médica/organización & administración , Integración de Sistemas , Telemedicina/instrumentaciónRESUMEN
The objective of this study was to share the experience of building an information security system for a regional collaborative medical platform (RCMP) and discuss the lessons learned from practical projects. Safety measures are analyzed from the perspective of system engineering. We present the essential requirements, critical architectures, and policies for system security of regional collaborative medical platforms.