K修饰MoS_(2)催化剂用于CO_(2)高选择性加氢制甲醇

在CO_(2)加氢领域,MoS_(2)催化剂表现出独特的潜力。然而MoS_(2)的边缘S空位对CH_(4)的生成更有利,这限制了目标产物甲醇的选择性。本工作中,我们发现,通过掺杂K助剂可以显著提高MoS_(2)催化CO_(2)选择性加氢制甲醇的性能,而未修饰的MoS_(2)主要产生CH_(4)。通过一系列的表征研究,我们发现,K原子更倾向于稳定在MoS_(2)的边缘位点上,并向MoS_(2)转移电子,从而增强了MoS_(2)边缘位点的碱性。这有助于CO_(2)的吸附活化,并以较低的能垒解离为CO。此外,K助剂还有助于调控CO中间体定向转化为甲醇而非CH_(4)。这一发现拓展了MoS_(2)材料在CO_(2)合成甲醇中的应用。通过掺杂K助剂,我们能够更高效地利用MoS_(2)催化CO_(2)转化为甲醇,对于减缓气候变化和开发清洁能源具有重要意义。

LncRNA GABPB1-AS1调控急性髓系白血病细胞增殖侵袭迁移及凋亡的作用和机制

目的:探究长非编码RNA(long non-coding RNA,LncRNA)GA结合蛋白转录因子β亚基1的反义RNA(antisense RNA of GA binding protein transcription factorβsubunit 1,GABPB1-AS1)靶向微小RNA-497-5p/热休克蛋白8(microRNA-497-5p/heat shock protein 8,miR-497-5p/HSPA8)轴调控急性髓系白血病(acute myeloid leukemia,AML)细胞增殖、侵袭迁移及凋亡的作用和机制。方法:HL-60细胞分为正常对照组、si-NC组、si-GABPB1-AS1组、si-GABPB1-AS1+NC inhibitor组、si-GABPB1-AS1+miR-497-5p inhibitor组。qRT-PCR检测LncRNA GABPB1-AS1、miR-497-5p和HSPA8表达;双荧光素酶报告基因实验验证LncRNA GABPB1-AS1、miR-497-5p和HSPA8的靶向关系;MTT检测细胞活力;Edu检测细胞增殖;Transwell小室实验检测侵袭和迁移;流式细胞仪检测细胞凋亡;Western blot检测增殖细胞核抗原(proliferating cell nuclear antigen,PCNA)、HSPA8、肿瘤转移相关蛋白2(metastasis-associated proteins,MTA2)、酵母Atg6同系物(homolog of yeast Atg6,Beclin-1)和Caspase-3蛋白水平;建立小鼠移植瘤模型验证LncRNA GABPB1-AS1对AML移植瘤生长的影响。结果:与人骨髓单核细胞相比,不同AML细胞系THP-1、NB4、U-937、HL-60中LncRNA GABPB1-AS1高表达[(1.29±0.10)、(1.58±0.12)、(2.02±0.17)、(3.17±0.24)vs.(1.02±0.07)]、miR-497-5p低表达[(0.94±0.07)、(0.75±0.03)、(0.57±0.03)、(0.25±0.01)vs.(1.05±0.09)]。由于HL-60细胞中LncRNA GABPB1-AS1表达最高,故选择该细胞系进行功能验证实验。敲低LncRNA GABPB1-AS1能降低HL-60细胞活力、Edu阳性率、细胞侵袭数、迁移数、HSPA8 mRNA及HSPA8、PCNA和MTA2蛋白表达,增加凋亡率、miR-497-5p及Caspase-3和Beclin-1蛋白表达(P<0.05)。miR-497-5p与LncRNA GABPB1-AS1、HSPA8之间分别存在靶向关系;抑制miR-497-5p表达能逆转LncRNA GABPB1-AS1敲低对HL-60细胞恶性生物学行为的抑制作用;抑制LncRNA GABPB1-AS1表达可抑制移植瘤生长。结论:LncRNA GABPB1-AS1敲低对AML细胞进展抑制作用,可能与上调miR-497-5p表达,下调HSPA8表达有关。

An Image Encryption Algorithm Based on BP Neural Network and Hyperchaotic System

To reduce the bandwidth and storage resources of image information in communication transmission, and improve the secure communication of information. In this paper, an image compression and encryption algorithm based on fractional-order memristive hyperchaotic system and BP neural network is proposed. In this algorithm, the image pixel values are compressed by BP neural network, the chaotic sequences of the fractional-order memristive hyperchaotic system are used to diffuse the pixel values. The experimental simulation results indicate that the proposed algorithm not only can effectively compress and encrypt image, but also have better security features. Therefore, this work provides theoretical guidance and experimental basis for the safe transmission and storage of image information in practical communication.

A method of elevated temperatures coupled with magnetic stirring to predict real time release from long acting progesterone PLGA microspheres

The object of the study was to develop a quick and reproducible accelerated in vitro release method to predict and deduce the function of the real time(37 °C) release for long acting PLGA microspheres. The method could be described in several steps. First, the release of the microspheres were studied using the sample and separate method at 37 °C with normal orbital shaking and elevated temperatures with magnetic stirring to further accelerate the release. Second, the most similar profile at elevated temperatures with the real time release was chosen with the help of the n value in the fitted Korsmeyer-Peppas Function. Third,the Weibull function and conversion ratio were used to deduce the function of real time release according to the chosen profile at elevated temperatures. The key point in this study was to provide a quick and precise method to predict the real time release for long acting progesterone PLGA microspheres. So the elevated temperatures coupled with magnetic stirring were used to accelerate the release further, and when there have many similar release profiles with the real time release at elevated temperatures, releasing time at elevated temperatures and the R2 of the final deduced function will be used to help choosing the most similar release profile with the real time release. Four different types of progesterone PLGA microspheres were used to verify the method, and all the deduced function correlated well with the real time releases, for R2 = 0.9912, 0.9781, 0.9918 and 0.9972, respectively.

Isolation and Preliminary Identification of Broad-spectrum Bacteriocin-producing Lactobacillus Strain CW3

[ Objective] This study aimed to screen and preliminarily identify LactobaciUus strain CW3. [ Method] Oxford cup double-plate method was used for preliminary screening of broad-spectrum bacteriacin-producing LactobaciUus strain; after eliminating the interference of organic acid and hydrogen peroxide, antibac- terial substances containing protein properties produced by the screened strain were detected; finally, the obtained strain was identified. [ Result] After elimination of interference factors such as organic acid and hydrogen peroxide, the fermentation supernatant of strain CW3 could stil｜ inhibit the growth of indicator strains; the antibacterial activity of fermentation broth was significantly reduced after treatment with trypsase and pepsase, which indicated that the produced antibacterial sub- stances were bacteriocins. Results of physiological and biochemical identification showed that strain CW3 belonged to Lactobacillus plantarum. [ Conclusion] CW3 is a broad-spectrum bacteriocin-producing LactobaciUus plantarum strain.

The effects of surface morphology on the aerosol performance of spray-dried particles within HFA 134a based metered dose formulations

The aim of this study was to produce fine particles with different corrugated degree of surface by spray-drying and to investigate the effect of surface morphology on in vitro aerosol performance of the particles within HFA 134a based metered dose formulations.Compositions of rizatriptan and scutellarin were spray-dried using different spray-drying parameters,and particles were suspended within HFA 134a.The surface morphology were determined using scanning electron microscopy(SEM),while the aerodynamic performance of MDIs was evaluated using a next generation pharmaceutical impactor.The surface morphology of spraydried particles could vary from smooth to moderately corrugated,and to raisin-like depending upon spray-drying parameters and preparation compositions.In general,increasing inlet temperature,decreasing feed concentration and/or adding leucine to the feed solution tended to increase the corrugated degree of particle surface.Deposition results indicated that raisinlike particle based MDIs for all compositions of the two drugs produced significantly better aerodynamic performance in terms of fine particle fractions and mass median aerodynamic diameters relative to the formulations of the corresponding smooth or slightly corrugated particles when the particle compositions were the same.The present results demonstrated that wrinkled particles increased fine particle fractions within surfactant-free MDI formulations.

Discourse Construction of Ideological and Political Education in Colleges and Universities under Multidisciplinary Discourse Theory

The discourse construction of ideological and political education in colleges and universities is an important task to strengthen the leadership and discourse power of ideological work in colleges and universities.The relevant theories of western multidisciplinary discourse research provide rich theoretical reference for the discourse construction of ideological and political education in colleges and universities.Based on linguistics,sociology,political science,philosophy and other disciplines,ideological and political education in colleges and universities should reasonably absorb its theoretical achievements on the sociality,power,democracy and authenticity of discourse,providing theoretical and practical references for the construction of ideological and political education discourse in colleges and universities in terms of content,power,expression and value.

First total synthesis,antitumor evaluation and target identification of mornaphthoate E:A new tubulin inhibitor template acting on PI3K/Akt signaling pathway

Mornaphthoate E(MPE)is a prenylated naphthoic acid methyl ester isolated from the roots of a famous Chinese medicinal plant Morinda officinalis and shows remarkable cytotoxicity against several human tumor cell lines.In the current project,the first total synthesis of(±)-MPE was achieved in seven steps and 5.6%overall yield.Then the in vitro anti-tumor activity of MPE was first assessed for both enantiomers in two breast cancer cells,with the levoisomer exerting slightly better potency.The in vivo anti-tumor effect was further verified by applying the racemate in an orthotopic autograft mouse model.Notably,MPE exerted promising anti-metastasis activity both in vitro and in vivo and showed no obvious toxicity on mice at the therapeutic dosage.Mechanistic investigations demonstrated that MPE acted as a tubulin polymerization stabilizer and disturbed the dynamic equilibrium of microtubules via regulating PI3K/Akt signaling.In conclusion,our work has provided a new chemical template for the future design and development of next-generation tubulin-targeting chemotherapies.

Effect of reduction pretreatment on the structure and catalytic performance of Ir-In_(2)O_(3)catalysts for CO_(2) hydrogenation to methanol

In_(2)O_(3)has been found a promising application in CO_(2)hydrogenation to methanol,which is beneficial to the utilization of CO_(2).The oxygen vacancy(O_(v))site is identified as the catalytic active center of this reaction.However,there remains a great challenge to understand the relations between the state of oxygen species in In_(2)O_(3)and the catalytic performance for CO_(2)hydrogenation to methanol.In the present work,we compare the properties of multiple In_(2)O_(3)and Ir-promoted In_(2)O_(3)(Ir-In_(2)O_(3))catalysts with different Ir loadings and after being pretreated under different reduction temperatures.The CO_(2)conversion rate of Ir-In_(2)O_(3)is more promoted than that of pure In_(2)O_(3).With only a small amount of Ir loading,the highly dispersed Ir species on In_(2)O_(3)increase the concentration of O_(v)sites and enhance the activity.By finely tuning the catalyst structure,Ir-In_(2)O_(3)with an Ir loading of 0.16 wt.%and pre-reduction treatment under 300℃exhibits the highest methanol yield of 146 mgCH_(3)OH/(gcat·hr).Characterizations of Raman,electron paramagnetic resonance,X-ray photoelectron spectroscopy,CO_(2)-temperature programmed desorption and CO_(2)-pulse adsorption for the catalysts confirm that more O_(v)sites can be generated under higher reduction temperature,which will induce a facile CO_(2)adsorption and desorption cycle.Higher performance for methanol production requires an adequate dynamic balance among the surface oxygen atoms and vacancies,which guides us to find more suitable conditions for catalyst pretreatment and reaction.

Crop pest image recognition based on the improved ViT method Author links open overlay panel

The crop pests and diseases in agriculture is one of the most important reason for the reduction of bulk grain and oil crops and the decline of fruit and vegetable crop quality,which threaten macroeconomic stability and sustainable development.However,the recognition method based on manual and instruments has been unable to meet the needs of scientific research and production due to its strong subjectivity and low efficiency.The recognition method based on pattern recognition and deep learning can automatically fit image features,and use features to classify and predict images.This study introduced the improved Vision Transformer(ViT)method for crop pest image recognition.Among them,the region with the most obvious features can be effectively selected by block partition.The self-attention mechanism of the transformer can better excavate the special solution that is not an obvious lesion area.In the experiment,data with 7 classes of examples are used for verification.It can be illustrated from results that this method has high accuracy and can give full play to the advantages of image processing and recognition technology,accurately judge the crop diseases and pests category,provide method reference for agricultural diseases and pests identification research,and further optimize the crop diseases and pests control work for agricultural workers in need.

Two simple memristive maps with adaptive energy regulation and digital signal process verification

Mathematical models can produce desired dynamics and statistical properties with the insertion of suitable nonlinear terms,while energy characteristics are crucial for practical application because any hardware realizations of nonlinear systems are relative to energy flow.The involvement of memristive terms relative to memristors enables multistability and initial-dependent property in memristive systems.In this study,two kinds of memristors are used to couple a capacitor or an inductor,along with a nonlinear resistor,to build different neural circuits.The corresponding circuit equations are derived to develop two different types of memristive oscillators,which are further converted into two kinds of memristive maps after linear transformation.The Hamilton energy function for memristive oscillators is obtained by applying the Helmholz theorem or by mapping from the field energy of the memristive circuits.The Hamilton energy functions for both memristive maps are obtained by replacing the gains and discrete variables for the memristive oscillator with the corresponding parameters and variables.The two memristive maps have rich dynamic behaviors including coherence resonance under noisy excitation,and an adaptive growth law for parameters is presented to express the self-adaptive property of the memristive maps.A digital signal process(DSP)platform is used to verify these results.Our scheme will provide a theoretical basis and experimental guidance for oscillator-to-map transformation and discrete map-energy calculation.

An adaptive energy regulation in a memristive map linearized from a circuit with two memristive channels

Nonlinear circuits can show multistability when a magnetic flux-dependent memristor(MFDM) or a charge-sensitive memristor(CSM) is incorporated into a one branch circuit,which helps estimate magnetic or electric field effects.In this paper,two different kinds of memristors are incorporated into two branch circuits composed of a capacitor and a nonlinear resistor,thus a memristive circuit with double memristive channels is designed.The circuit equations are presented,and the dynamics in this oscillator with two memristive terms are discussed.Then,the memristive oscillator is converted into a memristive map by applying linear transformation on the sampled time series for the memristive oscillator.The Hamilton energy function for the memristive oscillator is obtained by using the Helmholtz theorem,and it can be mapped from the field energy of the memristive circuit.An energy function for the dual memristive map is suggested by imposing suitable weights on the discrete energy function.The dynamical behaviors of the new memristive map are investigated,and an adaptive law is proposed to regulate the firing mode in the memristive map.This work will provide a theoretical basis and experimental guidance for oscillator-to-map transformation and discrete map energy calculation.

T2T-YAO: A Telomere-to-telomere Assembled Diploid Reference Genome for Han Chinese

Since its initial release in 2001,the human reference genome has undergone continuous improvement in quality,and the recently released telomere-to-telomere(T2T)version-T2T-CHM13—reaches its highest level of continuity and accuracy after 20 years of effort by working on a simplified,nearly homozygous genome of a hydatidiform mole cell line.Here,to provide an authentic complete diploid human genome reference for the Han Chinese,the largest population in the world,we assembled the genome of a male Han Chinese individual,T2T-YAO,which includes T2T assemblies of all the 22+X+M and 22+Y chromosomes in both haploids.The quality of T2T-YAO is much better than those of all currently available diploid assemblies,and its haploid version,T2T-YAO-hp,generated by selecting the better assembly for each autosome,reaches the top quality of fewer than one error per 29.5 Mb,even higher than that of T2T-CHM13.Derived from an individual living in the aboriginal region of the Han population,T2T-YAO shows clear ancestry and potential genetic continuity from the ancient ancestors.Each haplotype of T2TYAO possesses330-Mb exclusive sequences,3100 unique genes,and tens of thousands of nucleotide and structural variations as compared with CHM13,highlighting the necessity of a population-stratified reference genome.The construction of T2T-YAO,an accurate and authentic representative of the Chinese population,would enable precise delineation of genomic variations and advance our understandings in the hereditability of diseases and phenotypes,especially within the context of the unique variations of the Chinese population.

基于顶空进样气相色谱-质谱联用和非靶标代谢组学分析人参、西洋参和三七经蒸制后挥发性成分的转化

人参是全世界范围内广受欢迎的滋补品,经蒸制后补益效果更佳。先前对人参蒸制的研究主要集中在所含的皂苷,但对其挥发性成分研究较少。本研究建立了顶空进样气相色谱-质谱联用结合非靶标代谢组学方法,对人参、西洋参和三七在蒸制过程中挥发性成分的变化进行整体性表征。通过优化GC-MS色谱分离条件,采用HP-5MS弹性石英毛细管柱在38分钟内实现对人参、西洋参和三七生品及蒸制品(1-10 h)中挥发性成分的表征。从人参、西洋参和三七中分别鉴定出了106、106和105种挥发性成分。多元统计分析可以描述不同蒸制时间介导的人参、西洋参和三七的转化轨迹。最终,通过基于GC-MS的非靶标代谢组学分析,发现人参、西洋参和三七蒸制过程中分别有13、16和14种差异成分。值得注意的是,其中异戊醇、2-正戊基呋喃、正己醛、丁香烯和(-)-马兜铃烯可以区分人参的生品和炮制品;α-蒎烯、2-正戊基呋喃、己酸、2,3-丁二醇和丙酮酸可以区分西洋参生品和炮制品;莎草烯、糠醛、Δ-杜松烯、羟基丙酮和1-戊醇可以区分三七生品和炮制品。本研究所建立的气相色谱-质谱联用方法可以揭示中药中挥发性成分的变化,为进一步探讨中药炮制机理提供一种实用的分析工具。

A novel synthetic small molecule YF-452 inhibits tumor growth through antiangiogenesis by suppressing VEGF receptor 2 signaling

Tumor angiogenesis is characterized by abnormal vessel morphology, endowing tumor with highly hypoxia and unresponsive toward treatment. To date, mounting angiogenic factors have been discovered as therapeutic targets in antiangiogenic drug development. Among them, vascular endothelial growth factor receptor 2 （VEGFR2） inhibitors exerts potent antiangiogenic activity in tumor therapy. Therefore, it may provide a valid strategy for cancer treatment through targeting the tumor angiogenesis via VEGFR2 pathway. In this study, we established a high-profile compounds library and certificated a novel compound named N-（N-pyrrolidylacetyl）-9-（4-bromobenzyl）-l,3,4,9-tetrahydro-^-carboline （YF-452）, which remarkably inhibited the migration, invasion and tube-like structure formation of human umbilical vein endothelial cells （HUVECs） with little toxicity invitro. Rat thoracic aorta ring assay indicated that YF-452 significantly blocked the formation ofmicrovascular exvivo. In addition, YF-452 inhibited angiogenesis in chick chorioallantoic membrane （CAM） and mouse corneal micropocket assays. Moreover, YF-452 remarkably suppressed tumor growth in xenografts mice model. Furthermore, investigation of molecular mechanism revealed that YF-452 inhibited VEGF-induced phosphorylation of VEGFR2 kinase and the downstream protein kinases including extracellular signal regulated kinase （ERK）, focal adhesion kinase （FAK） and Src. These results indicate that YF-452 inhibits angiogenesis and may be a potential antiangiogenic drug candidate for cancer therapy.

Exploration of 5-cyano-6-phenylpyrimidin derivatives containing an 1,2,3-triazole moiety as potent FAD-based LSD1 inhibitors

Histone lysine specific demethylase 1(LSD1)has become a potential therapeutic target for the treatment of cancer.Discovery and develop novel and potent LSD1 inhibitors is a challenge,although several of them have already entered into clinical trials.Herein,for the first time,we reported the discovery of a series of 5-cyano-6-phenylpyrimidine derivatives as LSD1 inhibitors using flavin adenine dinucleotide(FAD)similarity-based designing strategy,of which compound 14 q was finally identified to repress LSD1 with IC50=183 nmol/L.Docking analysis suggested that compound 14 q fitted well into the FAD-binding pocket.Further mechanism studies showed that compound 14 q may inhibit LSD1 activity competitively by occupying the FAD binding sites of LSD1 and inhibit cell migration and invasion by reversing epithelial to mesenchymal transition(EMT).Overall,these findings showed that compound14 q is a suitable candidate for further development of novel FAD similarity-based LSD1 inhibitors.

A novel histone deacetylase inhibitor exerts promising anti-breast cancer activity via triggering AIFM1-dependent programmed necrosis

Dear Editor,Breast cancer is one of the most lethal cancers in women,with many patients still succumbing to this dis-ease[1].Accumulating evidence demonstrates that histone deacetylase inhibitors(HDACIs)are a promising therapeu-tic intervention for breast cancer[2],and many of them have shown favorable anti-cancer activities in both pre-clinical and clinical settings[3].However,most current HDACIs only exhibit limited efficacy against solid tumors with toxic side effects and readily produce drug resistance[4].Therefore,it is necessary to develop new HDACIs with improved anti-tumor activities and decreased toxic-ities for breast cancer therapeutics and investigate their mechanism of action.

Mean-field Macro Computation in Large-scale Cloud Service Systems with Resource Management and Job Scheduling

Service computing is an emerging and distributed computing mode in cloud service systems, and has become an interesting research direction for both academia and industry. Note that the cloud service systems always display new characteristics, such as stochasticity, large scale, loose coupling, concurrency non-homogeneity and heterogeneity;thus their load balancing investigation has been more interesting, difficult and challenging until now. By using resource management and job scheduling, this paper proposes an integrated, real-time and dynamic control mechanism for large-scale cloud service systems and their load balancing through combining supermarket models with not only work stealing models but also scheduling of public reserved resource. To this end, this paper provides a novel stochastic model with weak interactions by means of nonlinear Markov processes. To overcome theoretical difficulties growing out of the state explosion in high-dimensional stochastic systems, this paper applies the mean-field theory to develop a macro computational technique in terms of an infinite-dimensional system of mean-field equations. Furthermore, this paper proves the asymptotic independence of the large-scale cloud service system, and show how to compute the fixed point by virtue of an infinite-dimensional system of nonlinear equations. Based on the fixed point, this paper provides effective numerical computation for performance analysis of this system under a high approximate precision. Therefore, we hope that the methodology and results given in this paper can be applicable to the study of more general large-scale cloud service systems.