Micro-galvanic corrosion behaviour of Mg-(7,9)Al-1Fe-xNd alloys

The localized micro-galvanic corrosion process and the kinetic information of Mg-(7,9)Al-1Fe-x Nd alloys were investigated by in situ observation under electrochemical control and in situ atomic force microscopy(AFM)in an electrolyte environment.The results revealed that the formation of the Nd-rich phase in alloys resulted in a decrease in the Volta potential difference from~400 m V(AlFe3/α-Mg)to~220 mV(Nd-rich/α-Mg),reducing the corrosion products around the cathodic phase and corrosion current density of the microscale area.The addition of Nd significantly improved the corrosion resistance,mainly due to the suppression of the micro-galvanic corrosion between the second phases and substrate.Finally,the corrosion mechanism of Mg-(7,9)Al-1Fe-x Nd alloys was discussed based on in situ observations and electrochemical results.

In-situ AFM and quasi-in-situ studies for localized corrosion in Mg-9Al-1Fe-(Gd) alloys under 3.5 wt.% NaCl environment

Revealing the localized corrosion process of Mg alloy is considered as one of the most significant ways for improving its corrosion resistance.The reliable monitor should be high distinguishability and real-time in liquid environment.Herein,Mg-9Al-1Fe and Mg-9Al-1Fe-1Gd alloys were designed to highlight the impact of intermetallic on the corrosion behaviour.In-situ AFM with a special electrolyte circulation system and quasi-in-situ SEM observation were used to monitor the corrosion process of the designed alloys.SEM-EDS and TEM-SAED were applied to identify the intermetallic in the designed alloys,and their volta potentials were measured by SKPFM.According to the real-time and real-space in-situ AFM monitor,the corrosion process consisted of dissolution of anodicα-Mg phase,accumulation of corrosion products around cathodic phase and shedding of some fine cathodic phase.Then,the localized corrosion process of Mg alloy was revealed combined with the results of the monitor of corrosion process and Volta potential difference.

CircRASSF2靶向miR-218-5p调控胃癌细胞增殖、迁移和凋亡的研究

背景胃癌是常见的消化道肿瘤,具有较高的发病率和死亡率.环状RNAs(circular RNAs,circRNAs)被认为是多种人类癌症进展的关键调控子,包括胃癌.研究显示circRASSF2作为促癌因子调控癌症进程.然而其在胃癌进展中的作用及潜在分子机制尚不清楚.目的探讨circRASSF2影响胃癌细胞增殖、迁移和凋亡的分子机制.方法用实时荧光定量PCR分析胃癌组织、癌旁组织及GES-1、HGC-27和AGS细胞中circRASSF2和miR-218-5p的表达;双荧光素酶报告实验分析靶向关系;将HGC-27和AGS细胞分为si-circRASSF2组、si-NC组、miR-218-5p mimic组、miR-NC组、si-circRASSF2+anti-miR-NC组、si-circRASSF2+miR-218-5p Inhibitor组;3-(4,5-二甲基噻唑-2)-2,5-二苯基四氮唑溴盐检测细胞抑制率;克隆形成实验检测克隆形成数;流式细胞术检测细胞凋亡率;Transwell检测细胞迁移数.结果胃癌组织中circRASSF2表达上升,miR-218-5p表达下降,且二者表达呈负相关(P<0.05);在胃癌HGC-27和AGS细胞中,circRASSF2表达上调,而miR-218-5p表达下调(P<0.05).circRASSF2靶向调控miR-218-5p;敲低circRASSF2或过表达miR-218-5p促进HGC-27和AGS细胞抑制率和凋亡率,而降低克隆形成数和迁移细胞数(P<0.05).下调miR-218-5p可逆转circRASSF2敲低对细胞增殖、迁移、凋亡的影响.结论circRASSF2通过靶向miR-218-5p加速胃癌细胞增殖、迁移、抑制凋亡.

间充质干细胞来源外泌体在恶性肿瘤中的研究进展

间充质干细胞(mesenchymal stem cells,MSCs)是存在于各种组织中的多能基质细胞。外泌体为细胞间的通讯载体,能在细胞间传递脂质、核酸以及蛋白质等生物活性分子。MSCs分泌的外泌体(mesenchymal stem cell-derived exosomes,MSC-EXO)为肿瘤微环境(tumor microenvironment,TME)的主要组成部分,并且在肿瘤的发生发展、血管生成及转移过程中发挥重要作用。本文旨在对MSCs来源的外泌体在癌症研究及其对肿瘤的作用机制予以综述,为适当利用修饰的MSC-EXO作为肿瘤治疗的策略提供新思路。

3-N-butylphthalide improves neuronal morphology after chronic cerebral ischemia

3-N-butylphthalide is an ettectwe drug for acute iscemlc stroke. However, its effects on cnromc cerebral ischemia-induced neuronal injury remain poorly understood. Therefore, this study li- gated bilateral carotid arteries in 15-month-old rats to simulate chronic cerebral ischemia in aged humans. Aged rats were then intragastrically administered 3-n-butylphthalide. 3-N-butylphtha- lide administration improved the neuronal morphology in the cerebral cortex and hippocampus of rats with chronic cerebral ischemia, increased choline acetyltransferase activity, and decreased malondialdehyde and amyloid beta levels, and greatly improved cognitive function. These findings suggest that 3-n-butylphthalide alleviates oxidative stress caused by chronic cerebral ischemia, improves cholinergic function, and inhibits amyloid beta accumulation, thereby im- proving cerebral neuronal injury and cognitive deficits.

A Chance Constrained Optimal Reserve Scheduling Approach for Economic Dispatch Considering Wind Penetration

The volatile wind power generation brings a full spectrum of problems to power system operation and management, ranging from transient system frequency fluctuation to steady state supply and demand balancing issue. In this paper, a novel wind integrated power system day-ahead economic dispatch model, with the consideration of generation and reserve cost is modelled and investigated. The proposed problem is first formulated as a chance constrained stochastic nonlinear programming U+0028 CCSNLP U+0029, and then transformed into a deterministic nonlinear programming U+0028 NLP U+0029. To tackle this NLP problem, a three-stage framework consists of particle swarm optimization U+0028 PSO U+0029, sequential quadratic programming U+0028 SQP U+0029 and Monte Carlo simulation U+0028 MCS U+0029 is proposed. The PSO is employed to heuristically search the line power flow limits, which are used by the SQP as constraints to solve the NLP problem. Then the solution from SQP is verified on benchmark system by using MCS. Finally, the verified results are feedback to the PSO as fitness value to update the particles. Simulation study on IEEE 30-bus system with wind power penetration is carried out, and the results demonstrate that the proposed dispatch model could be effectively solved by the proposed three-stage approach. © 2017 Chinese Association of Automation.

Text Detection and Recognition for Natural Scene Images Using Deep Convolutional Neural Networks

Words are the most indispensable information in human life.It is very important to analyze and understand the meaning of words.Compared with the general visual elements,the text conveys rich and high-level moral information,which enables the computer to better understand the semantic content of the text.With the rapid development of computer technology,great achievements have been made in text information detection and recognition.However,when dealing with text characters in natural scene images,there are still some limitations in the detection and recognition of natural scene images.Because natural scene image has more interference and complexity than text,these factors make the detection and recognition of natural scene image text face many challenges.To solve this problem,a new text detection and recognition method based on depth convolution neural network is proposed for natural scene image in this paper.In text detection,this method obtains high-level visual features from the bottom pixels by ResNet network,and extracts the context features from character sequences by BLSTM layer,then introduce to the idea of faster R-CNN vertical anchor point to find the bounding box of the detected text,which effectively improves the effect of text object detection.In addition,in text recognition task,DenseNet model is used to construct character recognition based on Kares.Finally,the output of Softmax is used to classify each character.Our method can replace the artificially defined features with automatic learning and context-based features.It improves the efficiency and accuracy of recognition,and realizes text detection and recognition of natural scene images.And on the PAC2018 competition platform,the experimental results have achieved good results.

Effect of SP600125 on proliferation of embryonic stem cell

SP600125 is an inhibitor of c-Jun NH2-terminal kinase (JNK), which plays a fundamental role in regulating animal development. Using SP600125 to deal with the mouse embryonic stem cells, it is revealed that the number of the ESC colonies decreased and the size became smaller. With treatment by SP600125, the proliferation of mouse ES cells is seriously inhibited for the cycle arrested in the G2/M phase, and the effect of SP600125 on the ES cells displays correlation of dose and time. The obtained results indicate that JNK may be an important regulator in the progression of cell cycle at the G2/M cell phase for the ES cells.

Natural Cocoons Enabling Flexible and Stable Fabric Lithium–Sulfur Full Batteries

Lithium–sulfur batteries are highly appealing as highenergy power systems and hold great application prospects for flexible and wearable electronics.However,the easy formation of lithium dendrites,shuttle effect of dissolved polysulfides,random deposition of insulating lithium sulfides,and poor mechanical flexibility of both electrodes seriously restrict the utilization of lithium and stabilities of lithium and sulfur for practical applications.Herein,we present a cooperative strategy employing silk fibroin/sericin to stabilize flexible lithium–sulfur full batteries by simultaneously inhibiting lithium dendrites,adsorbing liquid polysulfides,and anchoring solid lithium sulfides.Benefiting from the abundant nitrogen-and oxygen-containing functional groups,the carbonized fibroin fabric serves as a lithiophilic fabric host for stabilizing the lithium anode,while the carbonized fibroin fabric and the extracted sericin are used as sulfiphilic hosts and adhesive binders,respectively,for stabilizing the sulfur cathode.Consequently,the assembled Li–S full battery provided a high areal capacity(5.6 mAh cm−2),limited lithium excess(90%),a high volumetric energy density(457.2 Wh L^(−1)),high-capacity retention(99.8%per cycle),and remarkable bending capability(6000 flexing cycles at a small radius of 5 mm).

Surface modulation of halide perovskite films for efficient and stable solar cells

As the main distribution place of deep-level defects and the entrance of water, the interface is critical to determining both the power conversion efficiency(PCE) and the stability of perovskite solar cells(PSCs). Suitable interface design can dramatically passivate interface defects and optimize energy level alignment for suppressing the nonradiative recombination and effectively extracting the photogenerated carriers towards higher PCE. Meanwhile, a proper interface design can also block the interface diffusion of ions for high operational stability. Therefore, interface modification is of great significance to make the PSCs more efficient and stable. Upon optimized material choices, the three-dimensional halide perovskite graded junction layer, low-dimensional halide perovskite interface layer and organic salt passivation layer have been constructed on perovskite films for superior PSCs, yet a systematic review of them is missing. Thus, a guide and summary of recent advances in modulating the perovskite films interface is necessary for the further development of more efficient interface modification.

Tissue Segmentation in Nasopharyngeal CT Images Using Two-Stage Learning

Tissue segmentation is a fundamental and important task in nasopharyngeal images analysis.However,it is a challenging task to accurately and quickly segment various tissues in the nasopharynx region due to the small difference in gray value between tissues in the nasopharyngeal image and the complexity of the tissue structure.In this paper,we propose a novel tissue segmentation approach based on a two-stage learning framework and U-Net.In the proposed methodology,the network consists of two segmentation modules.The first module performs rough segmentation and the second module performs accurate segmentation.Considering the training time and the limitation of computing resources,the structure of the second module is simpler and the number of network layers is less.In addition,our segmentation module is based on U-Net and incorporates a skip structure,which can make full use of the original features of the data and avoid feature loss.We evaluated our proposed method on the nasopharyngeal dataset provided by West China Hospital of Sichuan University.The experimental results show that the proposed method is superior to many standard segmentation structures and the recently proposed nasopharyngeal tissue segmentation method,and can be easily generalized across different tissue types in various organs.

Vericiguat treatment of heart failure: A systematic review and metaanalysis

BACKGROUND Heart failure(HF),an end-stage manifestation of various cardiac diseases,poses an enormous economic and health burden on society.Vericiguat may be an effective drug in the treatment of HF.AIM To explore by meta-analysis the efficacy and safety of Vericiguat in treating chronic heart failure.METHODS Databases,including PubMed,EMBASE,Web of Science,and Cochrane Library,were searched to collect all published randomized controlled trials(RCTs)on Vericiguat treatment of chronic heart failure from the earliest electronic records to those published in March 2023.Two investigators independently screened the literature according to inclusion and exclusion criteria,evaluated the quality of the studies,and extracted valid data before conducting a meta-analysis using RevMan5.4.RESULTS Four RCTs with 5919 patients were included,and the meta-analysis showed that treatment with 10 mg Vericiguat reduced the incidence of the primary endpoint(a composite of cardiovascular mortality and first heart-failure-related hospital-ization)in patients with chronic heart failure compared to placebo[relative risk(RR)=0.91,95%confidence interval(CI):0.85–0.98,P=0.01],and reduced the incidence of heart-failure-related hospitalization(RR=0.92,95%CI:0.84–1.00,P=0.05).However,for the incidence of cardiovascular and all-cause death,there were no significant differences between the Vericiguat and placebo groups.In addition,the two groups did not show significant differences in blood pressure,heart rate,and Kansas Cardiomyopathy Questionnaire physical limitation score.In terms of safety,10 mg Vericiguat did not increase the risk of adverse effects in patients with chronic heart failure.Vericiguat may increase the risk of symp-tomatic hypotension(RR=1.17,95%CI:0.98–1.39,P=0.08)and syncope(RR=1.18,95%CI:0.90–1.55,P=0.24),but not significantly.CONCLUSION Vericiguat(10 mg)was more effective than placebo in treating patients with chronic heart failure and had a better safety profile.

Origin of carbonate minerals and impacts on reservoir quality of the Wufeng and Longmaxi Shale, Sichuan Basin

The Ordovician-Silurian Wufeng and Longmaxi Shale in the Sichuan Basin were studied to understand the genesis and diagenetic evolution of carbonate minerals and their effects on reservoir quality. The results of geochemical and petrological analyses show that calcite grains have a negative Ce anomaly indicating they formed in the oxidizing environment of seawater. The high carbonate mineral contents in the margin of basin indicate that calcite grains and cores of dolomite grains appear largely to be of detrital origin. The rhombic rims of dolomite grains and dolomite concretions with the δ^(13)C of –15.46‰ and the enrichment of middle rare earth elements were formed during the sulfate-driven anaerobic oxidation of methane. The calcite in radiolarian were related to the microbial sulfate reduction for the abundant anhedral pyrites and δ^(13)C value of –11.34‰. Calcite veins precipitated in the deep burial stage with homogenization temperature of the inclusions ranging from 146.70 ℃ to 182.90 ℃. The pores in shale are mainly organic matter pores with pore size mainly in the range of 1–20 nm in diameter. Carbonate minerals influence the development of pores through offering storage space for organic matter. When calcite contents ranging from 10% to 20%, calcite grains and cement as rigid framework can preserve primary pores. Subsequently, the thermal cracking of liquid petroleum in primary pores will form organic matter pores. The radiolarian were mostly partially filled with calcite, which combining with microcrystalline quartz preserved a high storage capacity.

Multi-Task Learning Using Attention-Based Convolutional Encoder-Decoder for Dilated Cardiomyopathy CMR Segmentation and Classification

Myocardial segmentation and classification play a major role in the diagnosis of cardiovascular disease.Dilated Cardiomyopathy(DCM)is a kind of common chronic and life-threatening cardiopathy.Early diagnostics significantly increases the chances of correct treatment and survival.However,accurate and rapid diagnosis of DCM is still challenge due to high variability of cardiac structure,low contrast cardiac magnetic resonance(CMR)images,and intrinsic noise in synthetic CMR images caused by motion artifact and cardiac dynamics.Moreover,visual assessment and empirical evaluation are widely used in routine clinical diagnosis,but they are subject to high inter-observer variability and are both subjective and non-reproducible.To solve this problem,we proposed an effective unified multi-task framework for dilated cardiomyopathy CMR segmentation and classification simultaneously,and we firstly update one independent encoder from both recovery decoder and parallel attention path sharing some partial weights.This can encode both task choices into good embedding,but each one can achieve significant improvements respectively from the given embedding.It consists of three branches:extraction path,attention path,and recovery path,which allows the model to learn more higher-level intermediate representations and makes a more accurate prediction.We validated our approach on a DCM dataset,which contains 1155 CMR LGE images.Experimental results show that our multi-task network has achieved accuracy of 97.63%,AUC of 98.32%,demonstrating effectively segmenting the myocardium,quickly and accurately diagnosing the presence or absence of dilation.

Ultrathin and Air-Stable Lithium Metal Anodes with Superlong Cycling Life in Ether/Ester-Based Electrolytes

Ultrathin and air-stable Li metal anodes hold great promise toward high-energy and high-safety Li metal batteries(LMBs).However,the application of LMBs is technically impeded by existing Li metal anodes with large thickness,high reactivity,and poor performance.Here,we developed a novel and scalable approach for the construction of a 10-μm-thick flexible and air-stable Li metal anode by conformally encapsulating Li within a multifunctional VN film.Specifically,the highly lithiophilic VN layer guides a uniform deposition of Li,while abundant and multilevel pores arising from assembly of ultrathin nanosheets enable a spatially confined immersion of metallic Li,thus ensuring an ultrathin and sandwiched Li anode.More impressively,the strong hydrophobicity of VN surface can effectively improve the stability of anode to humid air,whereas the highly conductive framework greatly boosts charge transfer dynamics and enhances Li utilization and high-rate capability.Benefiting from such fascinating features,the constructed Li-VN anode exhibits ultrastable cycling stability in both ether(2500 h)and carbonate(900 h)electrolytes,respectively.Moreover,even exposed to ambient air for 12 h,the anode still can retain~78%capacity,demonstrating excellent air-defendable capability.This work affords a promising strategy for fabricating high-performance,high-safety,and low-cost LMBs.

Three dimensional phase-field simulation for non-isothermal binary alloy solidification: Comparison with LKT theory

Using the advanced algorithm combining parallel computing,adaptive mesh re-griding and multigrid methods,quantitative 3D phase-field simulations of non-isothermal solidification of binary alloy were carried out.The 3D phase-field simulation results were compared with the analytical LKT(Lipton,Kurz and Trivedi)theory.For comparison,the simulation and analytical results for 2D cases were also given.The 3D phase-field simulation results support the transport portion of the LKT theory.However,the tip radius and tip velocity predicted by the simulations are not in good agreement with the LKT theory over the whole range of undercooling.The stability parameter calculated from phase-field simulations varies significantly with the Peclet number,indicating that the stability criterion,which assumes that the stability parameter is constant,is invalid.

Correlation between serum ANXA7, miR-211 levels and RAGE gene polymorphisms and postoperative recurrence of ESD after smoking-induced gastric cancer

Objective:To investigate the correlation between serum ANXA7,miR-211 levels and RAGE gene polymorphisms and postoperative recurrence of ESD after smoking-induced gastric cancer.Methods:A total of 400 patients with gastric cancer who underwent ESD were randomly divided into recurrent group and non-recurred group according to whether they were relapsed.According to whether smoking was classified as smoking recurrence and smoking no recurrence group.Serum ANXA7,miR-211 levels and RAGE gene polymorphisms were compared between groups.Results:The smoking rate and serum ANXA7 and miR-211 levels in the relapse group were significantly higher than those in the non-recurrent group(P<0.05).Moreover,the polymorphisms of RAGE gene rs2070600 and rs184003 may be associated with the recurrence of gastric cancer(P<0.05).The levels of serum ANXA7 and miR-211 in the smoke relapse group were significantly higher than those in the non-recurrence group(P<0.05).Moreover,the polymorphisms of RAGE gene rs2070600 and rs184003 may be associated with recurrence of ESD after smoking-induced gastric cancer(P<0.05).The polymorphisms of serum ANXA7,miR-211 and RAGE genes may be associated with recurrence of ESD after smoking-induced gastric cancer(P<0.05).Conclusion:Smoking may be one of the factors that induce recurrence of gastric cancer after ESD,and smoking may cause elevation of serum ANXA7,miR-211 and mutation of RAGE gene,which may induce recurrence of gastric cancer after ESD.

Quasi-in-situ Observation and SKPFM Studies on Phosphate Protective Film and Surface Micro-Galvanic Corrosion in Biological Mg-3Zn-xNd Alloys

The phosphate protective film and micro-galvanic corrosion of biological Mg-3Zn-xNd (x = 0, 0.6, 1.2) alloys were investigated by scanning and transmission electron microscopy, quasi-in-situ observation, scanning Kelvin probe force microscopy (SKPFM) and electrochemical tests. The results revealed the Mg-Zn-Nd phases formed in Mg-3Zn alloy contained with Nd. Adding Nd resulted in a significant decline in the cracks of the phosphate protective film and micro-galvanic corrosion of alloys, which were recorded by quasi-in-situ observation. In addition, the Volta potential difference of Mg-Zn-Nd/α-Mg (~ 188 mV) was lower than MgZn/α-Mg (~ 419 mV) and Zn-rich/α-Mg (~ 260 mV), and the corrosion rates of alloys markedly decreased after the addition of 0.6 wt% Nd. The improvement in corrosion resistance of Nd-containing alloys was mainly attributed to the following: (i) the addition of Nd reduced the Volta potential difference (second phases/α-Mg);(ii) the phosphate protective film containing Nd_(2)O_(3) deposited on the surface of the alloys, effectively preventing the penetration of harmful anions.

Design of a 35 kV high-temperature superconducting synchronous machine with optimized field winding

This paper proposes the application of high-voltage stator-cable windings in superconducting machines,based on the characteristics of strong magnetic fields and large air gaps.Cross-linked polyethylene cable winding can be employed to achieve a rated voltage of 35 kV in direct-current(DC)-field superconducting machines,thereby enabling a direct connection between the superconducting machine and the power grid,eliminating the need for transformers.We first,through finite element analysis,demonstrate that the proposed high-voltage high-temperature superconducting machine not only meets the requirement of a 35 kV-rated voltage,but also exhibits minimal flux leakage,torque fluctuation,and harmonic distortion.We then compare three candidate types to discuss the tradeoff between the multi-group superconducting field winding arrangement and machine performances.We propose inverted trapezoidal superconducting field winding as a promising candidate,because it has minimal superconductivity material usage,the largest safety margin for the superconducting coils(SCs),low thrust ripple,and low total harmonic distortion with the desired 35 kV-rated voltage.Finally,through large-scale design parameter sweeping,we show how we selected the optimal parameters for field winding and validated them by the finite element method.

谷氨酸脱氢酶与几种肿瘤的关系

大多数生物体中都含有谷氨酸脱氢酶(Glutamate dehydrogenase, GDH)(E.C. 1.4.1.2–1.4.1.4)。在真核生物中,该酶主要存在于线粒体中,并在氮和碳的代谢以及信号通路中起着至关重要的作用。研究发现谷氨酸脱氢酶与肿瘤发生及发展有一定的关系,对于肿瘤研究具有一定意义,但是关于其与人类肿瘤的关系方面的综述很少见。文中对谷氨酸脱氢酶与乳腺癌、胶质瘤、结直肠癌以及卵巢癌等的关系进行了归纳和总结,希望可以为相关研究提供帮助。