检索结果-南通市图书馆

Chinese Chemical Letters 2016年第5期27卷 698-702页

作者： Kongara Damodar Jin-Kyung Kim jong-gab jun Department of Chemistry and Institute of Natural Medicine Hallym University Department of Biomedical Science College of Natural Science Catholic University of Daegu

An efficient approach has been developed for the synthesis of naturally occurring prenylated chalcones viz. kanzonol C （1）, stipulin （2）, crotaorixin （3）, medicagenin （4）, licoagrochalcone A （5） and abyssinone D （6） along with the pyranochalcones paratocarpin C （7）, anthyllisone （8） and 3-O-methylabyssinone A （9）. The key step of the synthesis is a Claisen-Schmidt condensation. Subsequently, their anti-inflammatory effects were investigated in lipopolysaccharides （LPSs）-induced RAW-264.7 macrophages. Of the synthesized chalcones, compounds 5 （IC50= 10.41 μmol[L）, 6 （IC50= 9.65 μmol/L） and 8 （IC50= 15.34 μmol/L） show remarkable activity with no cytotoxicity. Compound 9 （IC50 = 4.5 μmol/L） exhibits maximum （83.6%） nitric oxide （NO） inhibition, but shows slight cytotoxicity. The results reveal that the chalcones bearing the prenyl group at 3- and/or 5-position on ring A （acetophenone moiety）, i.e., 1-4 and 7 show weak, or no inhibition activity, whereas chalcones having the prenyl group only on ring B （aldehyde part）, i.e., 5, 6 and 8 show significant activity on the production of inflammatory mediated NO with no cytotoxicity.

关键词： Prenylated chalcone Pyranochalcone Claisen-Schmidt condensation Anti-inflammatory Nitric oxide (NO)

First synthesis and in vitro biological assessment of isosideroxylin,6,8-dimethylgenistein and their analogues as nitric oxide production inhibition agents

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2017年第5期28卷 1114-1118页

作者： jong-Woon jung Kongara Damodar Jin-Kyung Kim jong-gab jun Department of Chemistry and Institute of Applied Chemistry Hallym University Department of Biomedical Science College of Natural ScienceCatholic University of Daegu

A modular and efficient synthesis of the biologically significant C-methylisoflavones isosideroxylin（1）,6,8-dimethylgenistein（2） and their analogues（3-8） is established for the first *** synthesis is realized in 7-8 steps in overall yields of 16%-24%from commercially inexpensive phloroglucinol and features a high yielding Vilsmeier-Haack reaction,Friedel-Crafts acylation,Gammill＇s protocol and Suzuki coupling as the pivotal ***,these compounds evaluated for their inhibitory potency on the production of nitric oxide（NO） in lipopolysaccharide（LPS）-activated RAW-264.7 cells as an indicator of anti-inflammatory *** results showed that all the compounds decreased NO production in a dose-dependent manner without marked cytotoxicity and IC_（50） values are found in the range of 10.17-33.88 μmol/*** note,compounds 3 followed by 1,7 and 8 show comparable inhibitory activity with positive control（N-monomethyl-L-arginine,L-NMMA）.

关键词： Isosideroxylin 6 8-Dimethylgenistein Vilsmeier-Haack reaction Suzuki coupling Nitric oxide(NO) Anti-inflammatory

Chemical and mechanical properties of stainless, environment-friendly, and nonflammable Mg alloys (SEN alloys): A review

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2024年第3期12卷 841-872页

作者： jong Un Lee Hyun Ji Kim Sang-Cheol Jin Ye Jin Kim Young Min Kim Bong Sun You jun Ho Bae Sung Hyuk Park Advanced Metals Division Korea Institute of Materials ScienceChangwon 51508Republic of Korea Department of Materials Science and Metallurgical Engineering Kyungpook National UniversityDaegu 41566Republic of Korea Missile Research Institute Agency for Defense DevelopmentDaejeon 34060Republic of Korea

This review article provides overall understanding of stainless,environment-friendly,and nonflammable Mg alloys(SEN alloys)recently developed at the Korea Institute of Materials *** alloys are produced by adding small amounts of Ca and Y(each<1 wt%)into commercial Mg–Al based alloys,resulting in exceptional ignition and corrosion resistances and impressive mechanical *** main advantages of SEN alloys are as follows.(1)A dense multi-oxide layer of SEN alloys comprising MgO,CaO,and Y_(2)O_(3) impedes the outward dispersion of Mg vapor and the inward penetration of O_(2) during oxidation,thereby enhancing the oxidation and ignition resistances.(2)The presence of Ca-and Y-based second-phase particles in SEN alloys can enhance their corrosion resistance because Ca-containing particles prevent the spread of corrosion,and the replacement of Al-containing particles with less noble ones containing Y(e.g.,Al–Mn–Y or Al–Y particles)retards corrosion.(3)The addition of minor amounts of Ca and Y renders excellent mechanical properties due to improved strengthening *** enhanced properties are attributed to more pronounced dynamic recrystallization and grain refining behaviors caused by the second-phase particles during extrusion.(4)Despite the presence of various types of second-phase particles,the fatigue properties of SEN9 alloys are similar to those of commercial AZ91 alloys.(5)Simultaneous introduction of Ca and Y suppresses the formation of Mg17Al12 discontinuous precipitates during aging,leading to the enhanced elongation of aged SEN alloys.(6)Adding mischmetal into the SEN9 alloy leads to a six-fold enhancement in ***,the studies conducted on SEN alloys demonstrate their excellent ignition and corrosion resistances and mechanical properties,which broaden the industrial applications of Mg alloys by addressing their inherent weaknesses.

关键词： SEN magnesium alloy Corrosion resistance Ignition resistance Mechanical properties Extrudability.

SARS-CoV-2 aberrantly elevates mitochondrial bioenergetics to induce robust virus propagation

在线全文

学校读者我要写书评

暂无评论

Signal Transduction and Targeted Therapy 2024年第6期9卷 2702-2715页

作者： Hye Jin Shin Wooseong Lee Keun Bon Ku Gun Young Yoon Hyun-Woo Moon Chonsaeng Kim Mi-Hwa Kim Yoon-Sun Yi Sangmi jun Bum-Tae Kim jong-Won Oh Aleem Siddiqui Seong-jun Kim Department of Convergent Research of Emerging Virus Infection Korea Research Institute of Chemical TechnologyDaejeon 34114Republic of Korea Gyeongnam Biohealth Research Center Gyeongnam Branch InstituteKorea Institute of ToxicologyJinju 52834Republic of Korea Center for Research Equipment Korea Basic Science InstituteCheongjuChungcheongbuk-do 28119Republic of Korea Department of Biotechnology Yonsei UniversitySeoul 03722Republic of Korea Division of Infectious Diseases School of MedicineUniversity of CaliforniaSan DiegoLa JollaCA 92093USA Present address:Department of Microbiology Chungnam National University School of MedicineDaejeon 35015Republic of Korea

Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)is a‘highly transmissible respiratory pathogen,leading to severe multiorgan ***,knowledge regarding SARS-CoV-2-induced cellular alterations is *** this study,we report that SARSCoV-2 aberrantly elevates mitochondrial bioenergetics and activates the EGFR-mediated cell survival signal cascade during the early stage of viral ***-CoV-2 causes an increase in mitochondrial transmembrane potential via the SARS-CoV-2 RNAnucleocapsid cluster,thereby abnormally promoting mitochondrial elongation and the OXPHOS process,followed by enhancing ATP ***,SARS-CoV-2 activates the EGFR signal cascade and subsequently induces mitochondrial EGFR trafficking,contributing to abnormal OXPHOS process and viral *** EGFR inhibitors remarkably reduce SARS-CoV-2 propagation,among which vandetanib exhibits the highest antiviral *** of SARS-CoV-2-infected cells with vandetanib decreases SARS-CoV-2-induced EGFR trafficking to the mitochondria and restores SARS-CoV-2-induced aberrant elevation in OXPHOS process and ATP generation,thereby resulting in the reduction of SARS-CoV-2 ***,oral administration of vandetanib to SARS-CoV-2-infected hACE2 transgenic mice reduces SARS-CoV-2 propagation in lung tissue and mitigates SARS-CoV-2-induced lung *** also exhibits potent antiviral activity against various SARS-CoV-2 variants of concern,including alpha,beta,delta and omicron,in in vitro cell culture *** together,our findings provide novel insight into SARS-CoV-2-induced alterations in mitochondrial dynamics and EGFR trafficking during the early stage of viral infection and their roles in robust SARS-CoV-2 propagation,suggesting that EGFR is an attractive host target for combating COVID-19.

关键词： alterations aberrant thereby

Key issues on magnetic reconnection at Mercury

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Earth and Planetary Physics 2024年第5期8卷 673-685页

作者： jun Zhong Key Laboratory of Earth and Planetary Physics Institute of Geology and Geophysics Chinese Academy of Sciences

Magnetic reconnection processes and their impact on planetary magnetospheric dynamics exhibit significant differences due to differences in upstream solar wind conditions and internal planetary environments. Current understanding of reconnection phenomena at Mercury is rooted in the MESSENGER mission. However, direct detection of reconnection remains rare. Here, we aim to assess the limitations of MESSENGER in detecting reconnection in Mercury's space and to discuss key issues of reconnection that will be addressed by BepiColombo, including the dynamics of magnetic flux ropes, particle acceleration, density asymmetric reconnection,IMF-driven near-tail structures, and potential modes of magnetospheric convection.

关键词： magnetic reconnection Mercury MESSENGER BepiColombo

Numerical investigation of non-uniform temperature fields for proppant and fluid phases in supercritical CO_(2)fracturing

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Particuology 2024年第7期90卷 149-163页

作者： Boyu Liu jun Yao Research Center of Multiphase Flow in Porous Media China University of Petroleum(East China)Qingdao 266000China

The non-uniform temperature distribution in supercritical CO_(2)(Sc-CO_(2))fracturing influences the density,viscosity,and volume expansion or shrinkage rate of Sc-CO_(2),impacting proppant *** study presents a coupled computational fluid dynamics-discrete element method and heat transfer model to examine the effects of proppant bed shape and the heat transfers of proppant-wall,proppant-fluid,and fluid-wall on the fluid and proppant temperature *** Sc-CO_(2)volume expansion is assessed under various temperature conditions by evaluating the volume-averaged Sc-CO_(2)*** factors,including proppant size,shape,thermal conductivity,concentration,temperature difference,and injection velocity,are carefully analyzed to elucidate their *** findings elucidate the existence of four distinct zones in the fluid temperature *** zone exhibits different magnitudes of temperature change under diverse conditions and undergoes dynamic transformations with the development of the proppant *** fluid-wall heat transfer and the fluid temperatures in Zones C and D are significantly subject to the fluid injection velocity(governing the heating duration),the temperature difference between fluid and formation(impacting the magnitude of heat flux),and the proppant bed shape(controlling the effective heating area).Additionally,the proppant-wall and proppant-fluid heat transfers determine the temperatures of both the proppant bed and the fluid within Zone B,showing a strong correlation with proppant thermal conductivity,proppant size,injection velocity,and temperature *** proposed coupled model provides valuable insights into the temperature distributions and flow behaviors of temperature-dependent fracturing fluids and proppants.

关键词： CFD-DEM Heat transfer Compressible fluid CO_(2)sequestration Proppant transport

Geometric Error Identification of Gantry-Type CNC Machine Tool Based on Multi-Station Synchronization Laser Tracers

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2024年第2期37卷 150-162页

作者： jun Zha Huijie Zhang School of Mechanical Engineering Xi’an Jiaotong UniversityXi’an 710049China Xi’an Jiaotong University Suzhou Academy Suzhou 215123China

Laser tracers are a three-dimensional coordinate measurement system that are widely used in industrial *** propose a geometric error identification method based on multi-station synchronization laser tracers to enable the rapid and high-precision measurement of geometric errors for gantry-type computer numerical control(CNC)machine *** method also improves on the existing measurement efficiency issues in the single-base station measurement method and multi-base station time-sharing measurement *** consider a three-axis gantry-type CNC machine tool,and the geometric error mathematical model is derived and established based on the combination of screw theory and a topological analysis of the machine kinematic *** four-station laser tracers position and measurement points are realized based on the multi-point positioning principle.A self-calibration algorithm is proposed for the coordinate calibration process of a laser tracer using the Levenberg-Marquardt nonlinear least squares method,and the geometric error is solved using Taylor’s first-order linearization *** experimental results show that the geometric error calculated based on this modeling method is comparable to the results from the Etalon laser *** a volume of 800 mm×1000 mm×350 mm,the maximum differences of the linear,angular,and spatial position errors were 2.0μm,2.7μrad,and 12.0μm,respectively,which verifies the accuracy of the proposed *** research proposes a modeling method for the precise measurement of errors in machine tools,and the applied nature of this study also makes it relevant both to researchers and those in the industrial sector.

关键词： Multi-point positioning Multi-station synchronization CNC machine tool Geometric error Error separation

A generalized presentation of multi-caloric effects based on exterior derivative theory and its applications

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第8期76卷 156-163页

作者： jun Yin School of Materials Science and Engineering Nankai UniversityTianjin 300350China School of Mechanical Engineering and Automation Fuzhou UniversityFuzhou 350108China

The emerging concept of multi-caloric effects, introduced in 2010, entails the application of multiple interplay fields to a thermodynamic system. While multi-caloric effects are the main focus of experimental endeavors, theoretical considerations fall short of providing a thorough understanding. This paper introduces a comprehensive presentation on multi-caloric effects,employing the method and theory of exterior derivative formations. It addresses every aspect of thermodynamic systems, showcasing its applicability to multi-caloric materials(both singlephase and multi-phase materials), and its adaptability to different scenarios(either in single or multiple force fields). The formulation of Maxwell relationships, characterized by their generality and universality, enables a clear prediction in entropy and temperature, facilitating a distinct identification between independent and interdependent contributions from multi-caloric effects. These insights hold significant importance in designing and developing specialized thermodynamic materials, optimizing functional performances and exploring innovative mechanisms.

关键词： multicaloric effects Maxwell relations isothermal entropy adiabatic temperature

On the Monge–Kantorovich Mass Transfer Problem in Higher Dimensions

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2024年第8期40卷 1989-2004页

作者： Xiao jun LU School of Mathematics Southeast UniversityNanjing 210096P.R.China

This paper mainly investigates the approximation of a global maximizer of the Monge–Kantorovich mass transfer problem in higher dimensions through the approach of nonlinear partial differential equations with Dirichlet *** an approximation mechanism,the primal maximization problem can be transformed into a sequence of minimization *** applying the systematic canonical duality theory,one is able to derive a sequence of analytic solutions for the minimization *** the final analysis,the convergence of the sequence to an analytical global maximizer of the primal Monge–Kantorovich problem will be demonstrated.

关键词： Monge-Kantorovich mass transfer singular variational problem canonical duality theory

Low-protein diet supplemented with 1% L-glutamine improves growth performance, serum biochemistry, redox status, plasma amino acids, and alters fecal microbiota in weaned piglets

在线全文

学校读者我要写书评

暂无评论

Animal Nutrition 2024年第2期17卷 144-154页

作者： jun Li jun Bai Ying Yang Zhenlong Wu State Key Laboratory of Animal Nutrition and Feeding Department of Companion Animal Science China Agricultural University

Glutamine, one of the most abundant amino acids in the body, has been shown to exert various beneficial effects in pigs. However, knowledge regarding the role of dietary glutamine in low-protein diet-fed piglets remains scarce. The present study aimed to investigate the effects of different levels of L-glutamine on growth performance, serum biochemistry parameters, redox status, amino acids, and fecal microbiota in low-protein diet-fed piglets. A total of 128 healthy crossbred piglets(Landrace × Yorkshire)were randomly allocated into 4 groups of 4 replicate pens, with 8 piglets per pen. Piglets in the 4 groups were fed with corn and soybean meal-based low-protein diets(crude protein level, 17%) that contained0%, 1%, 2%, and 3% L-glutamine, respectively, for 28 d. Pigs administered 1% L-glutamine had greater body weight on d 28 and average daily gain(ADG, P < 0.01), whereas a lower feed to gain ratio(F:G) from d 1to 28(P < 0.01), compared to the other three groups. Besides, lower body weight on d 14 and 28, ADG,average daily feed intake, and higher F:G from d 15 to 28 and d 1 to 28 were observed in response to 2%and 3% L-glutamine treatments than 0% and 1% L-glutamine treatments(P < 0.01). Moreover, 1% Lglutamine reduced serum glucose, malondialdehyde, hydrogen peroxide concentrations and inhibited aspartate aminotransferase, alanine aminotransferase, myeloperoxidase activities in low-protein diet-fed piglets on d 14, with concomitantly upregulated catalase, total superoxide dismutase activities and glutathione level(P < 0.05). However, dietary 3% L-glutamine enhanced blood urea nitrogen content in pigs on d 14(P < 0.05). Further investigation revealed that 1% L-glutamine upregulated the serum glutamine, lysine, methionine, tyrosine, and reduced plasma valine content(P < 0.05). Additionally, 1% Lglutamine upregulated the abundance of p＿75＿a5, Clostridium, Lactobacillus, Prevotellaceae＿Prevotella,and Gemmiger in the stool of piglets on d 14, with the Streptococcus lev

关键词： Glutamine Low protein diet Pig Redox status Amino acid Microbiota