1,286 research outputs found

    RIS-Assisted SWIPT Network for Internet of Everything Under the Electromagnetics-Based Communication Model

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    In the Internet of Everything (IoE) scenarios, the extensive deployment of devices may result in more stringent power and communication needs. Within this context, we utilize the reconfigurable intelligent surface (RIS) to support the simultaneous wireless information and power transfer (SWIPT) system, whereby the stable transmission of energy and information services can be guaranteed. Specifically, we construct the system model through electromagnetics (EM), which is based on the scattering-parameter (S-parameter) analysis, for revealing the crucial factors of the practical hardware. Relying on the model, the energy-efficient (EE) maximization problem constrained to the quality of services (QoS) is proposed for the users with the framework of co-located receiver (Rx). However, the problem is more intractable due to the introduced channel model. To resolve it, we propose an effective optimization scheme. First, the Neuman series approximation method is adopted to deconstruct the EM transfer model. Then the reformed problem, which includes the variables (i.e., the PS ratio, the active beamformer, and the reflection-coefficient matrix), can be addressed through the strategy of alternative optimization (AO). Further, the inner convex approximation (INCA) scheme and Dinkelbachā€™s algorithm are applied to tackle each sub-problem. In the numerical simulation, we demonstrate that the array configuration can influence not only the hardware properties of RIS but also the EE performance of the whole system. Whatā€™s more, the proposed scheme performs better for the tightly-coupled RIS owing to the awareness of the mutual-coupling (MC) effect

    Graphene-modified nickel foam electrode for cathodic degradation of nitrofuranzone: Kinetics, transformation products and toxicity

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    Simple, efficient, and durable electrodes are highly demanded for practical electroĀ­chemical process. In this study, a reduced graphene oxide modified nickel foam electrode (GRā€‘NiĀ foam) was facilely prepared via one-step cyclic voltammetry electrodeposition of graĀ­phene oxide suspension onto the Ni foam. The electrochemical degradation of nitrofuranĀ­zone (NFZ, a kind of typical antibiotics) was studied on the GR-Ni foam cathode. The cyclic voltammetry and electrochemical impedance spectra analysis confirmed that presence of GR loading accelerated the electron transfer from the cathode surface to NFZ. With the applied cathode potential of āˆ’1.25 V (vs. Ag/AgCl), the removal efficiency of NFZ (C0Ā =Ā 20Ā mg Lāˆ’1) at the GR-Ni foam electrode reached up to 99Ā % within 30 min, showing a higher reaction rate constant (0.1297 mināˆ’1) than 0.0870 mināˆ’1 at the Pd-Ni foam and 0.0186 mināˆ’1 at the Ni foam electrode. It was also found that the pH, dissolved oxygen and NFZ initial concentration have slight effect on NFZ degradation at the GR-Ni foam electrode. The reactions first occurred at nitro groups (-NO2), unsaturated C=N bonds and N-N bonds to generate furan ring-containing products, and then these products were transformed into linear diamine products. The direct reduction by electrons was mainly responsible for NFZ reduction at the GR-Ni foam electrode. Even after 18 cycles, the removal efficiency of NFZ still reached up to 98Ā % within 1 h. In addition, the cathodic degradation process could eliminate the antibacterial activity of NFZ. The GR-Ni foam electrode would have a great potential in electrochemical process for treating wastewater containing furan antibiotics

    OAG-BERT: Pre-train Heterogeneous Entity-augmented Academic Language Models

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    To enrich language models with domain knowledge is crucial but difficult. Based on the world's largest public academic graph Open Academic Graph (OAG), we pre-train an academic language model, namely OAG-BERT, which integrates massive heterogeneous entities including paper, author, concept, venue, and affiliation. To better endow OAG-BERT with the ability to capture entity information, we develop novel pre-training strategies including heterogeneous entity type embedding, entity-aware 2D positional encoding, and span-aware entity masking. For zero-shot inference, we design a special decoding strategy to allow OAG-BERT to generate entity names from scratch. We evaluate the OAG-BERT on various downstream academic tasks, including NLP benchmarks, zero-shot entity inference, heterogeneous graph link prediction, and author name disambiguation. Results demonstrate the effectiveness of the proposed pre-training approach to both comprehending academic texts and modeling knowledge from heterogeneous entities. OAG-BERT has been deployed to multiple real-world applications, such as reviewer recommendations and paper tagging in the AMiner system. It is also available to the public through the CogDL package

    Graphene-modified nickel foam electrode for cathodic degradation of nitrofuranzone: Kinetics, transformation products and toxicity

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    Simple, efficient, and durable electrodes are highly demanded for practical electrochemical process. In this study, a reduced graphene oxide modified nickel foam electrode (GR-Ni foam) was facilely prepared via one-step cyclic voltammetry electrodeposition of graphene oxide suspension onto the Ni foam. The electrochemical degradation of nitrofuranzone (NFZ, a kind of typical antibiotics) was studied on the GR-Ni foam cathode. The cyclic voltammetry and electrochemical impedance spectra analysis confirmed that presence of GR loading accelerated the electron transfer from the cathode surface to NFZ. With the applied cathode potential of āˆ’1.25 V (vs. Ag/AgCl), the removal efficiency of NFZ (C0 = 20 mg Lāˆ’1) at the GR-Ni foam electrode reached up to 99 % within 30 min, showing a higher reaction rate constant (0.1297 mināˆ’1) than 0.0870 mināˆ’1 at the Pd-Ni foam and 0.0186 mināˆ’1 at the Ni foam electrode. It was also found that the pH, dissolved oxygen and NFZ initial concentration have slight effect on NFZ degradation at the GR-Ni foam electrode. The reactions first occurred at nitro groups (-NO2), unsaturated C=N bonds and N-N bonds to generate furan ring-containing products, and then these products were transformed into linear diamine products. The direct reduction by electrons was mainly responsible for NFZ reduction at the GR-Ni foam electrode. Even after 18 cycles, the removal efficiency of NFZ still reached up to 98 % within 1 h. In addition, the cathodic degradation process could eliminate the antibacterial activity of NFZ. The GR-Ni foam electrode would have a great potential in electrochemical process for treating wastewater containing furan antibiotics

    Activation of Ī²-Adrenoceptors by Dobutamine May Induce a Higher Expression of Peroxisome Proliferator-Activated Receptors Ī“ (PPARĪ“) in Neonatal Rat Cardiomyocytes

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    Recent evidence showed the role of peroxisome proliferator-activated receptors (PPARs) in cardiac function. Cardiac contraction induced by various agents is critical in restoring the activity of peroxisome proliferator-activated receptors Ī“ (PPARĪ“) in cardiac myopathy. Because dobutamine is an agent widely used to treat heart failure in emergency setting, this study is aimed to investigate the change of PPARĪ“ in response to dobutamine. Neonatal rat cardiomyocytes were used to examine the effects of dobutamine on PPARĪ“ expression levels and cardiac troponin I (cTnI) phosphorylation via Western blotting analysis. We show that treatment with dobutamine increased PPARĪ“ expression and cTnI phosphorylation in a time- and dose-dependent manner in neonatal rat cardiomyocytes. These increases were blocked by the antagonist of Ī²1-adrenoceptors. Also, the action of dobutamine was related to the increase of calcium ions and diminished by chelating intracellular calcium. Additionally, dobutamine-induced action was reduced by the inhibition of downstream messengers involved in this calcium-related pathway. Moreover, deletion of PPARĪ“ using siRNA generated the reduction of cTnI phosphorylation in cardiomyocytes treated with dobutamine. Thus, we concluded that PPARĪ“ is increased by dobutamine in cardiac cells

    Molecular role of GATA binding protein 4 (GATA-4) in hyperglycemia-induced reduction of cardiac contractility

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    <p>Abstract</p> <p>Background</p> <p>Diabetic cardiomyopathy, a diabetes-specific complication, refers to a disorder that eventually leads to left ventricular hypertrophy in addition to diastolic and systolic dysfunction. In recent studies, hyperglycemia-induced reactive oxygen species (ROS) in cardiomyocytes have been linked to diabetic cardiomyopathy. GATA binding protein 4 (GATA-4) regulates the expression of many cardio-structural genes including cardiac troponin-I (cTnI).</p> <p>Methods</p> <p>Streptozotocin-induced diabetic rats and H9c2 embryonic rat cardiomyocytes treated with a high concentration of glucose (a D-glucose concentration of 30 mM was used and cells were cultured for 24 hr) were used to examine the effect of hyperglycemia on GATA-4 accumulation in the nucleus. cTnI expression was found to be linked to cardiac tonic dysfunction, and we evaluated the expression levels of cTnI and GATA-4 by Western blot analysis.</p> <p>Results</p> <p>Cardiac output was lowered in STZ-induced diabetic rats. In addition, higher expressions of cardiac troponin I (cTnI) and phosphorylated GATA-4 were identified in these rats by Western blotting. The changes were reversed by treatment with insulin or phlorizin after correction of the blood sugar level. In H9c2 cells, ROS production owing to the high glucose concentration increased the expression of cTnI and GATA-4 phosphorylation. However, hyperglycemia failed to increase the expression of cTnI when GATA-4 was silenced by small interfering RNA (siRNA) in H9c2 cells. Otherwise, activation of ERK is known to be a signal for phosphorylation of serine105 in GATA-4 to increase the DNA binding ability of this transcription factor. Moreover, GSK3Ī² could directly interact with GATA-4 to cause GATA-4 to be exported from the nucleus. GATA-4 nuclear translocation and GSK3Ī² ser9 phosphorylation were both elevated by a high glucose concentration in H9c2 cells. These changes were reversed by tiron (ROS scavenger), PD98059 (MEK/ERK inhibitor), or siRNA of GATA-4. Cell contractility measurement also indicated that the high glucose concentration decreased the contractility of H9c2 cells, and this was reduced by siRNA of GATA-4.</p> <p>Conclusions</p> <p>Hyperglycemia can cause systolic dysfunction and a higher expression of cTnI in cardiomyocytes through ROS, enhancing MEK/ERK-induced GATA-4 phosphorylation and accumulation in the cell nucleus.</p

    The effect of adding a home program to weekly institutional-based therapy for children with undefined developmental delay: A pilot randomized clinical trial

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    AbstractBackgroundEarly rehabilitation for children with developmental delay without a defined etiology have included home and clinic programs, but no comparisons have been made and efficacy is uncertain. We compared a weekly visit for institutional-based therapy (IT) to IT plus a structured home activity program (HAP).MethodsSeventy children who were diagnosed with motor or global developmental delay (ages 6-48 months and mean developmental age 12.5 months) without defined etiology were recruited (including 45 males and 23 females). The outcomes included the comprehensive developmental inventory for infants and toddlers test and the pediatric evaluation of disability inventory.ResultsChildren who received only IT improved in developmental level by 2.11 months compared with 3.11 months for those who received a combination of IT and HAP (pĀ =Ā 0.000). On all domains of the comprehensive developmental inventory for infants and toddlers test, except for self-help, children who participated in HAP showed greater improvements, including in cognition (pĀ =Ā 0.015), language (pĀ =Ā 0.010), motor (pĀ =Ā 0.000), and social (pĀ =Ā 0.038) domains. Except on the subdomain of self-care with caregiver assistance, the HAP group showed greater improvement in all the pediatric evaluation of disability inventory subdomains (pĀ <Ā 0.05).ConclusionEarly intervention programs are helpful for these children, and the addition of structured home activity programs may augment the effects on developmental progression

    A compact ka-band active integrated antenna with a GaAs amplifier in a ceramic package

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    This letter presents the design of a Ka-band active integrated antenna in package (AIAiP). A monolithic microwave integrated circuit amplifier based on the GaAs process and a compact patch antenna based on the printed circuit board process are implemented, respectively. Then, the amplifier and antenna are assembled together in a specified package using the wire-bond process. Thus, compared to the traditional solutions, the transmission loss and the size of the proposed AIAiP are significantly reduced. Furthermore, the influence of the bonding wire and the package is taken into account in the design of the amplifier and the antenna, respectively. A good agreement between the simulation and measurement results can be observed. The proposed AIAiP occupies a compact size of 7 Ɨ 7 mm2. Meanwhile, it achieves -10-dB impedance bandwidth from 33.4 to 37.2 GHz and a peak gain of 18.9 dBi at 35 GHz. Additionally, the impact of the package size on the antenna performance has been demonstrated for future AIA designers

    Differences of Various Region-of-Interest Methods for Measuring Dopamine Transporter Availability Using T

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    This study was to investigate whether various region-of-interest (ROI) methods for measuring dopamine transporter (DAT) availabilities by single photon emission computed tomography (SPECT) are statistically different, whether results of medical research are thereby influenced, and causes of these differences. Eighty-four healthy adults with Tc99m-TRODAT-1 SPECT and magnetic resonance imaging (MRI) scans were included. Six major analysis approaches were compared: (1) ROI drawn on the coregistered MRI; (2) ROIs drawn on the SPECT images; (3) standard ROI templates; (4) threshold-ROIs; (5) atlas-based mappings with coregistered MRI; and (6) atlas-based mappings with SPECT images. Using the atlas-based approaches we assessed the influence of striatum ROIs by slice-wise and voxel-wise comparisons. In (5) and (6), three partial-volume correction (PVC) methods were also explored. The results showed that DAT availabilities obtained from different methods were closely related but quite different and leaded to significant differences in determining the declines of DAT availability per decade (range: 5.95ā€“11.99%). Use of 3D whole-striatum or more transverse slices could avoid biases in measuring the striatal DAT declines per decade. Atlas-based methods with PVC may be the preferable methods for medical research
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