Search

N-doped carbon encapsulated small size Ni3Fe particles were constructed successfully. Optimized Ni3Fe@NC-600 exhibits excellent ORR/OER performances in alkaline media.

Using polyvinyl alcohol (PVA), polylactic coglycolic acid (PLGA), and transforming growth factor-β (TGF-β1) as raw materials, PLGA-coated electrospun nanoscaffold (ESNS) PVA-TGF-β1@PLGA was prepared by the coaxial ES method. Its characterization was analyzed by scanning electron microscopy (SEM), high-performance liquid chromatography (HPLC), and Fourier transform infrared spectroscopy (FTIR). Seventy-five healthy New Zealand rabbits were randomly rolled into the control group (no treatment, group C), model group (intervertebral disc degeneration (IDD) model, group M), and nanofiber scaffold group (implant PVA- TGF-β1@PLGA, group P). HE staining was adopted to visualize the histological morphology of the intervertebral disc (IVD) endplate in the different groups. Sox-9, Collagen type II, and Aggrecan genes in different groups of IVD endplate tissues were detected by qPCR. Vascular endothelial growth factor (VEGF), Wnt3α, β-catenin, glycogen synthase kinase-3β (GSK-3β), and vitamin D receptor (VDR) protein in IVD endplate tissues of different groups was detected by immunohistochemistry. IVD VDR protein and IDD-related protein levels were detected by Western blot. Linear trend tests and correlations were adopted to analyze the relationship between different degrees of IDD and VDR level. The results showed that the average particle size of the PVA-TGF-β1@PLGA NSs was approximately 415 nm, and Fourier infrared detection proved that PVA-TGF-β1@PLGA NSs were prepared. Sox-9, Collagen Type II, and Aggrecan gene levels in group M were notably inferior to those in group C (P < 0.05). Sox-9, collagen type II, and aggrecan gene levels in group P were substantially increased versus group M (P < 0.05). β-catenin level in groups P and M was greatly superior to that in group C (P < 0.05). GSK-3β and VEGF levels in group P were increased relative to group M (P < 0.05), while that of Wnt3α was decreased (P < 0.05). Western blotting confirmed that there was a negative relationship between the expression of IDD-related proteins and VDR. The results showed that PLGA-coated ESNS could promote Collagen II expression in the matrix of the nucleus pulposus (NP), reduce proteoglycan loss, and promote cell proliferation and differentiation by regulating the Wnt/β-catenin signaling pathway (Wnt/β Sig). VDR level was negatively correlated with the development of IDD in rats.

Objective: To describe the clinical characteristics of Covid-19 in infants during the Omicron variant outbreak in Henan, 2022. Methods: We retrospectively analyzed the clinical data, epidemiological exposure, and maternal vaccination status of infants infected with Omicron variant admitted to Zhengzhou First People’s Hospital from October 20, 2022 to December 15, 2022. Results: We admitted 21 infants (12 males and 9 females). All had epidemiological exposure in household or nursing institution settings. The most common respiratory manifestations were fever (19 cases), cough (11 cases), and nasal congestion (8 cases). The most frequent gastrointestinal manifestations were anorexia and diarrhea (8 cases each) and vomiting (4 cases). Of the 12 infants who underwent complete blood count, 8 had normal white blood cell counts and 3 had leukopenia. C-reactive protein was normal in 11 cases and mildly elevated in 1 case. Chest CT showed increased lung markings in 7 cases, focal consolidation in 6 cases each, and ground-glass opacities in 5 cases. The mean time to negative conversion was 6.7 days. All 21 infants recovered and were discharged after symptomatic treatment, with a mean length of stay of 11.5 days. Two weeks after discharge, none had recurrence or retested positive for SARS-CoV-2 RNA. We found no correlations between maternal vaccination status and clinical symptoms or SARS-CoV-2 RNA negative conversion time (P>0.05). Conclusion: All Covid-19 infants had epidemiological exposure in household or nursing institution settings. They mostly had mild infection with respiratory and/or gastrointestinal symptoms and a good short-term prognosis.

Oxygen reduction reaction (ORR) is a key step in the operation of fuel cells and metal air cells, which needs some economic and efficient catalysts to improve its reaction kinetics process. In this work, nitrogen-doped carbon (N-C) catalyst material was prepared by one-step high-temperature pyrolysis with biomass waste cotton stalk as carbon/nitrogen precursor material and urea as auxiliary nitrogen source. The effect of temperature on the structure and performance of the prepared N-C catalyst was investigated. The experimental results show that a small temperature change of 25°C will cause a significant change in the structure of N-C material. N-C-900 samples prepared at 900°C had a larger specific surface area of 620 m2 g−1, significantly improved graphitization degree and nitrogen content (7.30 at%) and showed significantly better ORR performance than other samples in alkaline medium. The ORR activity of N-C-900 sample is the best, indicated by the highest Eonset (0.92 V) and E1/2 (0.85 V) of ORR, which are positively shifted by 20 and 30 mV compared with commercial Pt/C. Its ORR initial potential and half-wave potential are similar to those of commercial Pt/C, and it shows better ORR stability and methanol resistance than Pt/C.

NiFe-based nanoparticles attached to heteroatom-doped carbon are found to act as tremendously efficient oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) electrocatalysts. Nevertheless, it is extremely challenging to control the particle size and avoid aggregation. Herein, nitrogen-doped carbon encapsulated Ni

Spinal cord injury (SCI) is different from peripheral nerve injury; it results in devastating and permanent damage to the spine, leading to severe motor, sensory and autonomic dysfunction. SCI produces a complex microenvironment that can result in hemorrhage, inflammation and scar formation. Not only does it significantly limit regeneration, but it also challenges a multitude of transplantation strategies. In order to promote regeneration, researchers have recently begun to focus their attention on strategies that manipulate the complicated microenvironment produced by SCI. And some have achieved great therapeutic effects. Hence, reconstructing an appropriate microenvironment after transplantation could be a potential therapeutic solution for SCI. In this review, first, we aim to summarize the influential compositions of the microenvironment and their different effects on regeneration. Second, we highlight recent research that used various transplantation strategies to modulate different microenvironments produced by SCI in order to improve regeneration. Finally, we discuss future transplantation strategies regarding SCI.

Polyacrylonitrile (PAN) carbon fibers are often used to prepare high-performance paper-based materials owing to their high strength, good electrical and thermal conductivity, and superior comprehensive properties. In this study, a novel method for preparing PAN-based carbon fibers by centrifugal spinning was developed, and a stable and homogeneous PAN carbon fiber paper was successfully obtained. Subsequently, the formation process, microscopic morphology, electrical conductivity, electrochemical performance and hydrophobicity of the PAN carbon fiber paper were studied and evaluated. The results showed that the electrical conductivity of the PAN carbon fiber paper prepared via this method reached 43.250 s·cm−1, resistivity was as low as 0.023–0.033 Ω·cm, and contact angle exceeded 140°. This study adopted a new method to prepare PAN carbon fiber paper, which provided another method for the preparation of high-performance fiber paper.

A deep understanding of SARS-CoV-2-host interactions is crucial to the development of effective therapeutics. The role of non-coding regions of viral RNA (ncrRNAs) has not been scrutinized. We developed a method using MS2 affinity purification coupled with liquid chromatography-mass spectrometry (MAMS) to systematically map the interactome of SARS-CoV-2 ncrRNA in different human cell lines. Integration of the results defined the core and cell-type-specific ncrRNA-host protein interactomes. The majority of ncrRNA-binding proteins were involved in RNA biogenesis, protein translation, viral infection, and stress response. The 5′ UTR interactome is enriched with proteins in the snRNP family and is a target for the regulation of viral replication and transcription. The 3′ UTR interactome is enriched with proteins involved in the cytoplasmic RNP granule (stress granule) and translation regulation. We show that the ORF10 is likely to be a part of 3′ UTR. Intriguingly, the interactions between negative-sense ncrRNAs and host proteins, such as translation initiation factors and antiviral factors, suggest a pathological role of negative-sense ncrRNAs. Moreover, the cell-type-specific interactions between ncrRNAs and mitochondria may explain the differences of cell lines in viral susceptibility. Our study unveils a comprehensive landscape of the functional SARS-CoV-2 ncrRNA-host protein interactome, providing a new perspective on virus-host interactions and the design of future therapeutics.

Through in situ transmission electron microscopy (TEM) observation, we report the behaviors of phosphorus (P)-doped silicon nanowires (SiNWs) during electrochemical lithiation/delithiation cycling. Upon lithiation, lithium (Li) insertion causes volume expansion and formation of the crystalline Li15Si4 phase in the P-doped SiNWs. During delithiation, vacancies induced by Li extraction aggregate gradually, leading to the generation of nanopores. The as-formed nanopores can get annihilated with Li reinsertion during the following electrochemical cycle. As demonstrated by our phase-field simulations, such first-time-observed reversible nanopore formation can be attributed to the promoted lithiation/delithiation rate by the P dopant in the SiNWs. Our phase-field simulations further reveal that the delithiation-induced nanoporous structures can be controlled by tuning the electrochemical reaction rate in the SiNWs. The findings of this study shed light on the rational design of high-power performance Si-based anodes.

How to promote the carbon productivity embodied in trade and regional balanced development has become the focus of attention to combat climate change and improve regional management. Taking the Pan-Yangtze River Delta region for example and based on the input–output model, this paper explored the relationship between inter-industry economic spillover and embodied carbon productivity in trade from 2007 to 2012. Results indicated that the intra-regional multiplier effect presented a slow downward trend during the studied period, while the trend in the inter-regional integration was intensifying. Moreover, the multiplier effect of the lower reaches of the Yangtze River was relatively lower than that of the middle reaches. Owing to the geographical location and industrial structure, the industries in the middle reaches of the Yangtze River were strongly correlated. In addition, the regional multiplier effect was mostly concentrated in industries with high carbon emission intensity. The economic spillovers between regions showed a growing trend from 2007 to 2012, indicating that regional economic integration was further strengthened, and the economic spillovers in the Yangtze River Delta region were significantly higher than those in the middle reaches. Furthermore, from the perspective of embodied carbon productivity in trade, most of Shanghai’s carbon productivity to other regions was mostly less than 10,000 Yuan per ton, which means Shanghai had little demand for intermediate products of other regions, and inter-regional trade between Shanghai and other regions brought less total output and more environmental pollution to other regions, while Shanghai obtained more total output through trade. As embodied carbon productivity in trade in Jiangsu and Zhejiang was more than 10,000 Yuan per ton, Jiangsu and Zhejiang had played an important role in realizing the coordinated development of low carbon in the Pan-Yangtze River Delta. In particular, for Anhui and Jiangxi, embodied carbon productivity in the Yangtze River Delta region was relatively low. Therefore, in order to achieve green, coordinated, and high-quality economic development in the Pan-Yangtze River Delta region, Anhui and Jiangxi should not only strengthen regional cooperation with Shanghai, Zhejiang, and Jiangsu, but also they should avoid regional zero-sum game competition in regional climate policy. In other words, for policy-makers in the Pan-Yangtze River Delta, promoting the deep integration of industrial chain and regional coordinated development, and thus, improving carbon productivity during the regional development process, should receive more attention.

Guo Ma (Chinese-specific cursing terms) is a type of scolding expressions widely spread in colloquial Chinese, expressing such emotion as dislike, grudge, indignation. Searching the internet reveals that, while there are many comments and essays about this kind of words, a theoretically systematical discussion of their construction, pragmatic and textual function is rare. This paper, based on corpus observation and questionnaire analysis, aims at exploring the composition, types, functions and pragmatic forces of Chinese-specific cursing terms ta ma de and its variants. It is revealed that: (1) There are eight main types of Chinese-specific cursing words in ta ma de and its variants; (2) These cursing terms under observation convey not only negative attitude and emotion as traditionally recognized but also neutral or even positive attitude and emotion; (3) Chinese national curse ta ma de and its variants are phrases used not only to perform the pragmatic function of swearing but also play a grammatical cognitive function. The researchers do not intend to offer a deliberate justification for these terms but show that they are not diabolic expressions and deserve a full attention of linguists.

On the basis of reviewing the previous reading strategies research, we find that the previous three general models of reading strategies have their own limitations and that, although all the previous models take notice of the role relevance plays in reading, they invariably fail to specify how relevance functions in reading. Relevance is not only a notion of large category which includes relevant information, relevant knowledge of language, culture, background, context, etc. necessary for reading comprehension, but also a mechanism by which these aspects of information and knowledge are accessed and retrieved for reading process and comprehension process. Enlightened by the Relevance Theory, the authors in the present research aims at analyzing strategy for reading and reading instruction and proposing a relevance-based approach to reading and reading instruction. They have given in it a systematic analysis of the cognitive features and cognition laws involved in reading and comprehension and put forward the notion of Relevance Strategy in reading and reading instruction, arguing that reading or reading instruction is a cognitive-inferential process, with Relevance as the kernel, of searching relevant information and knowledge and arriving at maximal relevance (i.e. solution or interpretation of reading material). Either the bottom-up, or top-down, or interactive models of strategies cannot ignore the kernel function of relevance. In the application of sub-strategies, relevance is also playing a major role. The authors, therefore, also argue that the traditional decoding model of Reading Comprehension instruction should be replaced by a pragma-cognitive model. Reading (Comprehension) should not be regarded as merely decoding words, phrases or sentences, but as an integral cognition of the reading material. A teacher should help students form a unitary cognitive environment so as to cognize the reading material as a whole.

To put the policy of civil coal governance environment, the clean and efficient use of technology and civilian cainuanlu practical application within consideration, this paper designed a set of flue gas desulfurization dust removal integration of recovery of waste heat from flue gas treatment system, in order to achieve the recovery of waste heat of flue gas and reduce cainuanlu particulate matter and sulfur dioxide emissions. The flue gas treatment system mainly used the structure of the spiral coil heating and stainless steel tube, and will recovery the smoke waste heat ; There are three dust removal processes: the strainer mesh filtration of the entire unit, adsorption of modified activated coke and water spray cleaning; Desulfurization part was designed to operate the easy drawer cabinet structure, using the modified adsorption properties of activated coke processing SO2 in flue gas. The experimental results show that the processing system of dust removal and desulfurization efficiency is at 80%.

A low temperature growth method based on electron cyclotron resonance plasma-enhanced metal organic chemical vapor deposition system (ECR-PEMOCVD) was proposed for the growth of gallium nitride (GaN) films on ordinary soda-lime glass substrates with sputtered Cu as intermediate layer (Cu/glass substrates). The influence of deposition temperature on the properties of the GaN films on Cu/glass substrates was systematically investigated by means of In-situ reflection high energy electron diffraction, X-ray diffraction, atomic force microscopy and photoluminescence spectra. With this method, high c-orientated crystalline GaN films with relatively smooth surface were achieved on amorphous Cu/glass substrate at an extremely low temperature of ~400 °C. The successfully growth of crystalline GaN films on amorphous Cu/glass substrates show great potential for significant improvements in the scalability and cost of GaN based devices, since the adverse effects with high temperature process for glass substrates can be effectively suppressed by this technique.

Gallium nitride (GaN) films were deposited on Ni metal substrate using electron cyclotron resonance plasma-enhanced metal organic chemical vapor deposition system. With this approach, highly c-oriented GaN films with smooth surface were obtained at an extremely low temperature of ~480 °C. The trimethyl gallium (TMGa) flux dependent structural, morphological, and optical characteristics of GaN films were investigated by X-ray diffraction analysis, reflection high energy electron diffraction, atomic force microscopy and photoluminescence analysis. The results indicate that it is feasible to deposit GaN films on Ni metal substrate under the proper deposition procedures. The high quality GaN films with high c-axis orientation and strong ultraviolet emission peak are successfully achieved under the optimized TMGa flux of 1.2 sccm. The GaN/Ni structure has great potential for the development of high power devices with excellent heat dissipation.

Highly c -axis oriented GaN films were deposited on Cu coated glass substrates using electron cyclotron resonance plasma enhanced metal organic chemical vapor deposition (ECR-PEMOCVD). In-situ reflection high energy electron diffraction (RHEED), X-ray diffraction (XRD) and atomic force microscopy (AFM) were used to systematically analyze the influence of TMGa flux on the crystalline quality of the GaN films. GaN films with strong c -axis preferred orientation were achieved under the optimal TMGa flux of 1.4 sccm. Moreover, a strong near band edge (NBE) emission peak located at 354 nm was observed in the room temperature PL spectrum for the optimized GaN sample. The GaN/Cu/glass structure shows great potential for application in large area low cost GaN-based LED devices.

Annealing studies were performed to investigate the effects of heat treatment on InN thin films by changing the annealing condition from vacuum to high pressure N 2 . A significant variation of ∼400 meV in the surface work function was observed for InN films. The basic principles of Kelvin probe measurement revealed that the surface band bending E SBB is crucial in investigating the significant changes of surface work function on the InN. The stoichiometric ratio imbalance of In and N was indirectly determined to be the main cause of the variation in band bending by analyzing the X-ray diffraction and energy dispersive X-ray measurements. Thus, the annealing treatment could be an effective method to adjust the surface work function of InN by changing the annealing condition from vacuum to high pressure N 2 .

Au-20 wt% Sn eutectic solder is used as bumps in flip chip package of power LED (Light Emitting Diode) due to its excellent properties. The Au/Sn dual-layer films were fabricated on Si wafer by pulse electroplating of Au and Sn sequentially, and the solid–solid interfacial reaction during aging and the eutectic reaction during reflow soldering were investigated in the present work. After storage at room temperature for 1 week, three phases of AuSn, AuSn2 and AuSn4 were sequentially formed at the Au/Sn (10 μm/10 μm) interface, and the thickness of this reaction region was about 5 μm. Firstly, AuSn4 was formed at the Au/Sn interface, and then AuSn and AuSn2 were formed at the Au/AuSn4 interface. After aging at 150 °C for 5 and 10 h, a similar layered structure of AuSn/AuSn2/AuSn4 was also observed. Due to the faster diffusion of Au to Sn layer, all the Sn elements were consumed after aging at 150 °C for 15 h and AuSn4 layer gradually transformed into AuSn and AuSn2 layers. For the specimen of Au/Sn (9 μm/6 μm) films on Si chip, a bamboo-shoot-like microstructure of Au5Sn/AuSn/AuSn2 was formed in the reaction region after reflowed at 280 °C for 10 s; while a typical two-phase (Au5Sn and AuSn) eutectic microstructure was formed after reflowed at 280 °C for 60 s.

The symplectic geometry approach is introduced for accurate bending analysis of rectangular thin plates with two adjacent edges free and the others clamped or simply supported. The basic equations for rectangular plates are first transferred into Hamilton canonical equations. Using the symplectic approach, the analytic solution of rectangular thin plate with two adjacent edges simply supported and the others slidingly supported is derived. Accurate bending solutions of title problems are then obtained using the superposition method. The approach used in this paper eliminates the need to pre-determine the deformation function and is hence more reasonable than conventional methods. Numerical results are presented to demonstrate the validity and efficiency of the approach as compared with those reported in other literatures.

Exact bending solutions of fully clamped orthotropic rectangular thin plates subjected to arbitrary loads are derived using the finite integral transform method. In the proposed mathematical method one does not need to predetermine the deformation function because only the basic governing equations of the classical plate theory for orthotropic plates are used in the procedure. Therefore, unlike conventional semi-inverse methods, it serves as a completely rational and accurate model in plate bending analysis. The applicability of the method is extensive, and it can handle plates with different loadings in a uniform procedure, which is simpler than previous methods. Numerical results are presented to demonstrate the validity and accuracy of the approach as compared with those previously reported in the bibliography.

Objective: To elucidate the effects of Wenyangzhenshuai granule on expression of extracellular signal-regulated kinase 1/2 (ERK1/2) and 5 (ERK5) in the myocardial tissue using a rabbit model of adriamycin-induced chronic heart failure. Materials and methods: Rabbits were divided into heart failure positive control, adriamycin injection, and adriamycin injection with Wenyangzhenshuai treatment (low, medium and high dose) groups. Cardiac function and cardiac hypotrophy were measured in all groups. Besides, myocardial expression of ERK1/2 and ERK5 phosphorylation were evaluated by Western blotting and ERK1/2 and ERK5 mRNA levels by RT-PCR. The cardiac structure and cardiac function were also compared using histology staining and electron microscope. Results: Adriamycin injection led to cardiac failure reflected by decreased left ventricular ejection fraction (LVEF), left ventricular fractional shortening (LVFS), E/A ratio, and increased cardiac hypertrophy, both of which have been improved by Wenyangzhenshuai granule treatment (all P0.05), indicating an alteration in the activity/phosphorylation levels of these proteins instead of the transcription levels. Conclusion: we found a beneficial effect of Wenyangzhenshuai treatment in partially decelerating the progression of CHF. Such effect was probably through the role of Wenyangzhenchuan in diminishing p-ERK1/2 and raising p-ERK5 level in myocardial tissue.

To evaluate the clinical application value of nasal airway obstruction objectively and quantificationally by acoustic rhinometry (AR) in children with adenoid hypertrophy.Thirty patients with adenoid hypertrophy were examined with AR and questionnaire at preoperative and eight weeks after surgery. The values of AR were compared with those of 27 normal controls.There were significant differences between preoperative and postoperative in NAR and NPV (P0.01), no significant difference was observed between preoperative and postoperative in MCSA (P0.05); There were significant differences in NAR, NPV, MCSA between the patient group and the control group (P0.01); There were significant differences between postoperative and the control group in NPV and MCSA (P0.01), no significant difference was observed between postoperative and the control group in TNAR (P0.05); There was negative correlation between MCSA and symptom scores (r = -0. 519, P0.05). No significant correlation was observed between NAR and NPV and symptom scores (P0.05).Acoustic rhinometry was an objective and quantitative method for evaluating nasal airway in children with adenoid hypertrophy. In interpretation the relationships of the results of acoustic rhinometry reflection measurements and subjective symptoms, MCSA should be the main reference.

The symplectic geometry method is introduced for exact bending solutions of moderately thick rectangular plates with two opposite edges simply supported. The basic equations for the plates are first transferred into Hamilton canonical equations. The whole state variables are then separated. Using the method of eigenfunction expansion in the symplectic geometry, typical examples for plates with selected boundary conditions are solved and exact bending solutions obtained. Since only the basic elasticity equations of the plates are used, this method eliminates the need to pre-determine the deformation function and is hence more reasonable than conventional methods. Numerical results were presented to demonstrate the validity and accuracy of this approach as compared to those reported in other literatures.

Highly c-axis-oriented GaN films were deposited on Ti coated glass substrates using low temperature electron cyclotron resonance plasma enhanced metal organic chemical vapor deposition system (ECR-PEMOCVD) with trimethyl gallium (TMGa) as gallium source. The influence of TMGa flux on the properties of GaN films were systematically investigated by reflection high energy electron diffraction (RHEED), X-ray diffraction analysis (XRD), atomic force microscopy (AFM) and Raman scattering. The GaN film with small surface roughness and high c-axis preferred orientation was successfully achieved at the optimized TMGa flux of 1.0 sccm. The ohmic contact characteristic between GaN and Ti layer was clearly demonstrated by the near-linear current-voltage (I–V) curve. The GaN/Ti/glass structure has great potential to dramatically improve the scalability and reduce the cost of solid-state lighting light emitting diodes.