Search

The uniqueness problems of the j-th derivative of a meromorphic function f(z) and the k-th derivative of its shift f(z + c) are investigated in this paper, where j, k are integers with 0 ⩽ j < k. We show that when f (j) (z) and f (k) (z + c) share one IM value and two partially shared values CM, the uniqueness result remains valid under some additional hypotheses. With one CM value and two partially shared values CM, a uniqueness theorem about the j-th derivative of f(z) and the k-th derivative of its shift f(z + c) is also proved.

In this paper, phenolic resin hollow microspheres (PHM) were prepared using in-situ polymerization and used as flame-retardants for TPU. The structure and composition of PHM were characterized by Scanning Electron Microscope (SEM). The potential of PHM as flame retardant was verified by thermogravimetric analysis (TG). Then, the flame retardancy and toxicity reduction of PHM in TPU/PHM composites were verified by cone calorimeter test (CCT) and Thermogravimetric Analysis-infrared Spectrometry (TG-IR). It has been found that comparing TPU/PHM-4 sample containing 4.0 wt% PHM with pure TPU, the peak heat release rate (pHRR) was reduced by 61.6%, the total smoke release (TSR) by 23.2%, and the CO production by 86.2%, respectively. The SEM, Laser Raman Spectroscopy Test (LRS), and other tests were carried out to test the char residues after CCT, and the mechanism of PHM in the process of flame retardant TPU was reasonably deduced. In a word, PHM is very effective as a flame retardant of TPU.

梭形细胞血管瘤（spindle cell hemangioma）是1986年首次提出的一种罕见病变，好发于青年四肢远端皮下软组织。镜下观察可见海绵状血管区、实性梭形细胞区、裂隙状血管区及乳头结构，极易误诊为其他血管源性肿瘤。本文报道1例发生在67岁女性患者胸骨的梭形细胞血管瘤，随访9个月余，病情稳定，无复发征象。.

A new visible imaging system characterizing a flexible optical design and delivering high resolution frames is established on the HL-2A tokamak. It features a modular configuration, consisting of a front-end imaging lens, a set of bilateral telecentric relay lenses, and a camera. To avoid the effects of plasma radiation (x and gamma-rays) and magnetic field variation on the camera, it should be away from the coils. Therefore, the length of the relay lenses determines the total size of the imaging system. The main feature of this imaging system is to realize the variation of field of view (FOV) by interchanging the front-end prime lenses or by using a zoom lens directly rather than designing the optical system afresh, which lowers the cost drastically. The primary purpose of varying FOV is to enrich the versatility of this system, i.e., focusing on a narrow FOV such as gas puff imaging or a wide FOV such as the plasma cross sections. During the HL-2A experiments, this visible imaging system is used to provide high quality pictures of the plasma–wall interaction, divertor detachment, pellet injections, and so on. The frames confirmed that a strong radiation close to the X point is correlated with the completely detached inner target.

Hydrogen bonding interactions alter the nanoscale reaction mechanisms of many chemistries. Yet, it remains unclear how they affect heterogeneously catalyzed decomposition of formic acid (FA), a rea...

The unprecedented ability of computations to probe atomic-level details of catalytic systems holds immense promise for the fundamentals-based bottom-up design of novel heterogeneous catalysts, which are at the heart of the chemical and energy sectors of industry. Here, we critically analyze recent advances in computational heterogeneous catalysis. First, we will survey the progress in electronic structure methods and atomistic catalyst models employed, which have enabled the catalysis community to build increasingly intricate, realistic, and accurate models of the active sites of supported transition-metal catalysts. We then review developments in microkinetic modeling, specifically mean-field microkinetic models and kinetic Monte Carlo simulations, which bridge the gap between nanoscale computational insights and macroscale experimental kinetics data with increasing fidelity. We finally review the advancements in theoretical methods for accelerating catalyst design and discovery. Throughout the review, we provide ample examples of applications, discuss remaining challenges, and provide our outlook for the near future.

A CO2 -mediated hydrogen storage energy cycle is a promising way to implement a hydrogen economy, but the exploration of efficient catalysts to achieve this process remains challenging. Herein, sub-nanometer Pd-Mn clusters were encaged within silicalite-1 (S-1) zeolites by a ligand-protected method under direct hydrothermal conditions. The obtained zeolite-encaged metallic nanocatalysts exhibited extraordinary catalytic activity and durability in both CO2 hydrogenation into formate and formic acid (FA) dehydrogenation back to CO2 and hydrogen. Thanks to the formation of ultrasmall metal clusters and the synergic effect of bimetallic components, the PdMn0.6 @S-1 catalyst afforded a formate generation rate of 2151 molformate molPd-1 h-1 at 353 K, and an initial turnover frequency of 6860 mol H2 molPd-1 h-1 for CO-free FA decomposition at 333 K without any additive. Both values represent the top levels among state-of-the-art heterogeneous catalysts under similar conditions. This work demonstrates that zeolite-encaged metallic catalysts hold great promise to realize CO2 -mediated hydrogen energy cycles in the future that feature fast charge and release kinetics.

$Z_{\mathrm {eff}}$ is measured by two visible bremsstrahlung diagnostics on HL-2A tokamak, one of which uses a high spectral resolution spectrometer coupled with an electron multiplied CCD (temporal resolution of 100 Hz), and the other uses a filterscope system (temporal resolution of 1 MHz). The bremsstrahlung brightness measured by them coincides with each other very well. $\bar {Z}_{\mathbf {eff}}$ is systematically measured under different discharge conditions, such as divertor and limiter configurations, ohmic and auxiliary heating phases, before and after siliconization, and $L$ – $H$ transition. Under ohmic phase, $\bar {Z}_{\mathbf {eff}}$ is higher in the limiter configuration than that in the divertor configuration by a factor of ~1.5 under high-density regime. $\bar {Z}_{\mathbf {eff}}$ increases in all cases of auxiliary heating scenarios due to enhanced plasma–wall interaction, accompanied by influx increases of low ionization states of impurities such as C2+ and Fe1+ in plasma edge. Siliconization for wall conditioning is prominently effective in lowering the main impurity influxes in plasma edge and thus the impurity level, and a concentration of ~4% for carbon and ~0.2% for iron is roughly evaluated for a typical nonsiliconized plasma. A simple relationship that $Z_{\mathrm {eff}}$ is positively correlated with $\Phi _{\mathrm {in}}$ and $\tau _{\mathrm {p}}$ is verified from the L - and $H$ -mode features, where $\Phi _{\mathrm {in}}$ is the impurity influx and $\tau _{\mathrm {p}}$ the particle confinement time. A nearly constant $\bar {Z}_{\mathbf {eff}}$ evolution is observed during $L$ – $H$ and $H$ – $L$ transition and it seems that $\bar {Z}_{\mathbf {eff}}$ is insensitive to $L$ – $H$ and $H$ – $L$ transition under some $Z_{\mathrm {eff}}$ (0) threshold. The $Z_{\mathrm {eff}}$ profiles are flat/weakly hollow in plasma core region (rho $Z_{\mathrm {eff}}$ (0) and tend to be peaked when $Z_{\mathrm {eff}}$ (0) is larger than 3, which agrees with the neoclassical theory prediction.

Isotope effects greatly enhance our understanding of chemical reactions in heterogeneous catalysis. Despite their widespread use, there is limited understanding about how realistic reaction conditions, such as the coverage of surface adsorbates, affect them. Here, we study the influence of hydrogen (H) coverage on the thermodynamic and kinetic isotope effects of H2/D2 dissociative adsorption on the close-packed, open, and stepped surfaces of 12 transition metals: Ag, Au, Co, Cu, Fe, Ir, Ni, Re, Pd, Pt, Rh, and Ru, over a catalytically relevant temperature range. Through first-principles density functional theory calculations, we show that increasing coverage has two effects: i) it may change preferred adsorption sites and transition state geometries, and ii) it increases the vibrational frequencies of adsorbed H due to the interactions between H atoms. Empirically, isotope effects decrease in absolute value with increasing coverage for most of our studied systems, indicating a relative shift in stability in favor of the D-substituted minima and transition states. This is likely due to the consistent influence of the latter factor, which affects all structures. Higher temperatures reduce the magnitude of these decreases. Our findings provide insights into the nanoscale mechanisms by which coverage influences isotope effects, which will affect how we interpret experimentally measured isotope effects. They also point towards new applications of isotope effects in catalysis, such as for quantifying adsorbate coverages as well as for elucidating adsorption and active sites on the surfaces of catalysts.

Numerical investigations on the pressure crash with a low magnetic shear profile in Tokamaks are carried out through the three-dimensional, toroidal, and nonlinear MHD code CLT. We find that there exist at least three different kinds of pressure crashes. The first type is that one cold bubble forms and merges into the hot core, which is the standard case for the nonlinear evolution of the quasi-interchange mode. The second type is two cold bubbles forming and squeezing the hot core, leading to fast pressure crashes. The third one is similar to that caused by the resistive-kink mode, i.e., an m/n = 1/1 magnetic island grows up and fills up the whole central region. The thresholds for these kinds of pressure crashes are systematically discussed.

Anastomotic leak is one of inevitable postoperative complications of rectal cancer. With the improvement of surgical techniques, the enhancement of the cognization of rectal cancer, and the development of surgical instruments, surgical procedures of rectal cancer are getting more sophisticated. The anastomosis is performed lower and lower, however the incidence of anastomotic leak is not significantly decreased. In addition, different from intraperitoneal anastomotic leak, the low rectal anastomotic leak after low anterior resection has many special issues in the diagnosis and treatment in clinic. The incidence of peritonitis caused by low anastomotic leak is low, the onset time is late, and symptoms of peritonitis are mild. So most low anastomotic leak is treated conservatively, second surgical repair or resection of anastomotic site is rarely performed, and proximal intestinal diversion is commonly performed. In the prevention of low anastomotic leak, some techniques and precautions during the perioperative period and identification of high risk factors might play important roles. Combined our clinical experiences, we introduced the diagnosis, treatment, prevention and research progression of low anastomotic leak after anterior resection of low rectal cancer, we hope it would be helpful.吻合口漏是直肠癌术后不可避免的并发症之一。随着手术技术和认知理念的提高、手术器械和设备的不断发展，直肠癌手术操作越来越精细，低位直肠癌手术的吻合口越来越低，但吻合口漏的发生率却没有显著下降。除此之外，直肠癌低位前切除术后与腹膜内的吻合口漏在诊断及治疗上有一定的区别，低位吻合口漏发生腹膜炎的概率小、时间晚、症状轻；其在处理上以保守治疗为主，较少行二次手术修补或切除吻合口，多行近端肠管改道转流。在预防低位吻合口漏方面，除了识别和警惕高危因素外，术中及术后的一些注意事项和操作技巧可能起着重要作用，包括肠系膜下动脉结扎位置、预防性造口、放置引流管、吻合口腔镜下缝合加固和使用黏合剂。相信随着临床医生的认识。医疗技术的提高和医疗器械的改进，低位吻合口漏发生率也将会越来越少。.

Formic acid (HCOOH or FA) is a clean, safe, and renewable hydrogen storage material. Although Au catalysts decompose vapor-phase FA with high activity and selectivity toward hydrogen, the active site and reaction mechanism remain unclear. Here, we show that the subnanometric Au18 cluster (0.8 nm in diameter) is likely the active species for FA decomposition. We performed coverage self-consistent, density functional theory-based kinetic Monte Carlo simulations of FA decomposition on gas-phase Au18 clusters, predicting 100% selectivity toward hydrogen and turnover frequencies close to experimentally determined values. The active site is made up of a triangular ensemble of three atoms each possessing a coordination number of 5. Although there are two active site ensembles on the Au18 cluster, their occupations are strongly correlated because of strong, stabilizing interactions between pairs of open-shell adsorbates mediated by the superatomic nature of the cluster. Because the occupation of the active sites blocks the dissociation of additional HCOOH molecules, there is kinetic isolation between turnovers: only one HCOOH molecule can dissociate on the cluster at a time. This explains the extraordinary, experimentally observed selectivity of Au catalysts toward HD during decomposition of HCOOD and DCOOH. Our work offers nanoscale insights into the reaction mechanisms of FA decomposition over Au. This represents a rare example of heterogeneous catalysis by a cluster that catalyzes reactants one molecule at a time. Our work on Au18 thus sheds light on how the unique electronic properties of subnanometric clusters can be used to design quasi-molecular catalysts with high activity and selectivity.

In order to reconstruct the plasma current density, the Current Profile Fitting (CPF) code has been successfully developed on the HL-2A tokamak. A seven-channel motional Stark effect (MSE) ...

In power discrete trench devices, the introduction of a TEOS capping layer in the PMD stack greatly alleviates the HTRB and THB reliability marginality problem. The failure mechanisms of HTRB Vth drift and THB Idss drift are inadequate proton (H+) gettering sites in the PMD bulk and moisture accumulation on the PMD surface, respectively. Utilization of a capping layer in the PMD stack enables the PMD surface to be free of Phosphorus (P) which is responsible for moisture build-up and hence THB failure, and at the same time keeping the PMD bulk with high level of P concentration for more H+gettering sites and hence better HTRB performance.

In this study, we tried to illuminate the role and underlying mechanism of beta-elemene in esophageal squamous cell carcinoma especially the metastasis. 3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide assay was performed to determine the cytotoxicity of beta-elemene and its role in esophageal squamous cell carcinoma cell proliferation. Wound healing assay and transwell assays were used to elucidate the roles of betaelemene on cell migration and invasion abilities of esophageal squamous cell carcinoma cells. Quantitative polymerase chain reaction and western blot assays were carried out to assess the messenger RNA and protein expression under beta-elemene treatment. Immunofluorescence staining was performed to detect the heat shock protein 70 expression regulated by beta-elemene. The heat shock protein 70 ectopic expression plasmid was used to perform the rescue experiments. In this study, we found that beta-elemene significantly inhibited the cell survival and cell proliferation and suppressed cell migration and invasion abilities of esophageal squamous cell carcinoma cell line. Mechanistically, we observed that beta-elemene downregulated heat shock protein 70 expressions and reversed epithelial-mesenchymal transition. Furthermore, the studies also indicated that beta-elemene downregulated the phosphorylation of extracellular regulated kinase, mothers against decapentaplegic homolog 2 and mothers against decapentaplegic homolog 3 expression. In addition, we confirmed that ectopic expression of heat shock protein 70 not only promoted cell migration, epithelialmesenchymal transition and mothers against decapentaplegic homolog 2 phosphorylation in esophageal squamous cell carcinoma cell line cells, but also reversed beta-elemene suppressed cell migration in TE-1 cells. Taken together, all results elucidated that beta-elemene suppresses metastasis of human esophageal squamous cell carcinoma by modulating the expression of heat shock protein 70 and the activation of extracellular regulated kinase and transforming growth factor beta signaling pathways at least partially.

This study involves the research progress in pathophysiological mechanism of dyskinesia in Parkinson’s disease. Levodopa-induced dyskinesia is a complication characterized by involuntary movements in Parkinson’s patients after long-term treatment with levodopa. Dyskinesia is a kind of abnormal movement involving the face, neck, arm, leg and axial muscles. It often occurs on the serious side of the disease. It may be manifested as variety of phenomenologies, such as choreiform, dystonia, ballism, myoclonus and other forms of abnormal movements can manifest as well. At present, the research on the mechanisms of levodopa-induced dyskinesia is not yet fully understood. Nigrostriatal degeneration and levodopa administration are considered to be the basis of levodopa-induced dyskinesia. There appears to be variety mechanisms involved, such as abnormal dopaminergic transmission in presynaptic and postsynaptic membrane as well as non-dopaminergic systems. Nigrostriatal degeneration is considered to be the basis and premise of levodopa-induced dyskinesia. With the deepening of the research, non-dopaminergic systems such as glutamate, serotonin, adenosine, cholinergic and epinephrine have been proved to be involved in the occurrence of dyskinesia in animal models and clinical studies. This article is a more detailed review of the possible pathophysiological mechanisms of levodopa-induced dyskinesia, especially non-dopaminergic systems.

This study aims to investigate the biological function of circular RNA ABCB10 (circ-ABCB10) in regulating the progression of glioma and to study the possible underlying mechanisms.The expression levels of circ-ABCB10, miR-620 and FABP5 mRNA in glioma tissues, normal surrounding tissues and glioma cell lines were measured by Real-time PCR (RT-PCR). Circ-ABCB10 was silenced by siRNA in glioma cell lines (U87, T98G). The proliferation, migration and invasion of glioma cells were measured by MTT, wound healing and transwell assays, respectively. The relationship between circ-ABCB10, miR-620 and FABP5 was tested by Dual-Luciferase assay. The expression of proteins was measured by Western blot. The cell cycle distribution and apoptosis were measured by flow cytometry.The expression levels of circ-ABCB10 and FABP5 in glioma tissues and cells were significantly higher than those in their normal counterparts. Moreover, the expression of miR-620 was lower in glioma tissues. Silencing of circ-ABCB10 in glioma cells significantly inhibited the proliferation, migration and invasion of glioma cells. Moreover, downregulation of circ-ABCB10 induced cell cycle arrest and apoptosis in glioma cells. Furthermore, inhibition of miR-620 showed the opposite effects to silencing circ-ABCB10 on glioma cells. Dual-Luciferase reporter assays demonstrated that circ-ABCB10 could bind to miR-620 and that FABP5 was a direct target of miR-620. Western blot results showed that circ-ABCB10 could stabilize the expression of FABP5, while miR-620 decreased the expression of FABP5. Furthermore, overexpression of FABP5 abrogated the silencing effects of circ-ABCB10 in glioma cells.These data suggest that circ-ABCB10 affects glioma progression by regulating the miR-620/FABP5 axis, and circ-ABCB10 might be used as a potential target for the treatment of glioma.

A CO

A Fast Charge eXchange Recombination Spectroscopy (CXRS) diagnostic with eight radial channels has been implemented on a HuanLiu-2A (HL-2A) tokamak with a time resolution of up to 10 kHz monitoring helium II spectra or 1 kHz monitoring carbon VI spectra. The crucial aspects of the fast CXRS are to improve the spectral intensity and the acquisition frequency. The spectral intensity has been greatly enhanced by customized fiber bundles. The main boost in optimizing the acquisition frequency is achieved by binning more pixel rows of the charge coupled device (CCD) representing one radial channel and by reducing the effective image area of the CCD. Consequently, the sawtooth oscillations of ion temperature and rotation velocity are continuously observed for the first time in the HL-2A tokamak.

To explore the mechanism of fibroblast growth factor 7 (FGF7) gene silencing in regulating viability, apoptosis, invasion of retinoblastoma (RB) cell line HXO-Rb44 and angiogenesis.Human normal retinal vascular endothelial cells ACBRI-181 was set as the normal group. The cultured RB cell lines HXO-Rb44 were divided into three groups: the blank group (without plasmid transfection), negative control group (transfection of FGF7 plasmid), and the si-FGF7 group (transfection of FGF7 siRNA plasmid). Quantitative Real Time-Polymerase Chain Reaction and Western blot were used to measure the mRNA and protein expression of B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), angiopoietin-2 (Ang-2), and proliferating cell nuclear antigen (PCNA) in each group. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, transwell invasion assay, and flow cytometry were used, respectively, to assess cell viability, invasive capability, and cell apoptosis in each group.The mRNA and protein expression of FGF7, Bcl-2, VEGF, bFGF, Ang-2, and PCNA were significantly decreased, and the mRNA and protein expression of Bax were significantly increased in the si-FGF7 group than in the blank group (all p0.05). Compared with the blank group, the si-FGF7 group had significantly decreased cells invasive capability, cell viability at 48 h and 72 h and proliferation, and significantly increased apoptosis rate (all p0.05).FGF7 gene silencing can inhibit the viability and invasion of RB cells and the expression of angiogenesis-related factors and can promote RB apoptosis.

This study aims to explore the role of GNAS in accelerating the progression of osteoporosis by inhibiting osteogenesis of BMSCs by the Wnt pathway.GNAS levels in OP tissues and BMSCs undergoing osteogenesis for different time points were detected. Regulatory effects of GNAS on osteogenesis-related gene expressions, ALP activity, capability of mineralization, and activation of the Wnt pathway in BMSCs were assessed through a series of functional experiments. At last, rescue experiments were performed to further verify the significance of the Wnt pathway during GNAS-mediated osteogenesis development.GNAS was downregulated in OP tissues relative to normal bone tissues. With the prolongation of osteogenesis, GNAS level gradually increased in BMSCs. Knockdown of GNAS downregulated expression levels of ALP and RUNX2, and attenuated ALP activity and capability of mineralization in BMSCs. GNAS was able to activate the Wnt pathway in BMSCs. Notably, overexpression of Wnt3a could reverse the regulatory effects of GNAS on osteogenesis-related gene expressions, ALP activity, and capability of mineralization in BMSCs.Downregulation of GNAS suppresses osteogenesis of BMSCs through the Wnt pathway, thus aggravating the progression of osteoporosis.