资源类型

期刊论文 1318

年份

2024 3

2023 175

2022 187

2021 196

2020 113

2019 56

2018 44

2017 65

2016 47

2015 61

2014 52

2013 53

2012 30

2011 29

2010 54

2009 32

2008 26

2007 38

2006 3

2005 2

展开 ︾

关键词

SARS-CoV-2 7

微波散射计 5

COVID-19 4

Cu(In 4

HY-2 4

2型糖尿病 3

GPS 3

Ga)Se2 3

HY-2 卫星 3

HY-2A卫星 3

光催化 3

微波辐射计 3

CCS 2

CO2利用 2

CO2封存 2

CO2捕集 2

DORIS 2

HY-2A 2

严重急性呼吸综合征冠状病毒2 2

展开 ︾

检索范围:

排序: 展示方式:

Influence of short chain ceramides and lipophilic penetration enhancers on the nano-structure of stratum corneum model membranes studied using neutron diffraction

Annett SCHROETER, Tanja ENGELBRECHT, Reinhard H. H. NEUBERT

《化学科学与工程前沿(英文)》 2013年 第7卷 第1期   页码 29-36 doi: 10.1007/s11705-013-1302-0

摘要: Oriented stratum corneum model lipid membranes were used to study the influence of the short chain ceramides (CER)[NP] and [AP] as well as the impact of the lipophilic penetration enhancer molecules oleic acid (OA) and isopropyl myristate (IPM) on the lipid nanostructure. The influence of the enhancer molecules were studied using specifically deuterated OA and IPM and neutron diffraction. H NMR spectroscopy was used to study the impact of the ceramides’ degree of order within the stratum corneum model lipid membranes. It was found that CER[NP] forms two very stable phases with high resistance against temperature increase. Phase B showed unusual hydration behavior as no water uptake of this phase was observed. The H NMR spectroscopic measurements showed that CER[NP] based ternary model system had a higher state of lamellar order in comparison to CER[AP] based lipid matrix. The studies confirmed that the short chain ceramides, particularly CER[NP], have a very high impact on the integrity of the Stratum corneum lipid bilayers. The penetration enhancer OA has not influenced the repeat distance of the model membrane based on CER[AP], and was not able to induce a phase separation in the investigated lipid matrix. However, a disorder and a fluidisation of the model membranes were observed when OA was incorporated. IPM showed the same effect but two phases (assigned as phase A and B) appeared, when IPM was used as penetration enhancer and incorporated into the model membrane. Furthermore, two arrangements of IPM were identified in phase A using deuterated IPM. A model of the nanostructure of the Stratum corneum lipid membranes is presented.

关键词: nano-structure of the stratum corneum     ceramide     penetration enhancer     model membrane     neutron diffraction     2H NMR spectroscopy    

Application and mechanism of polysaccharide extracted from Enteromorpha to remove nano-ZnO and humic acid in coagulation process

Jianzhang Sun, Baoyu Gao, Yuanxia Luo, Moxi Xue, Xing Xu, Qinyan Yue, Yan Wang

《环境科学与工程前沿(英文)》 2018年 第12卷 第3期 doi: 10.1007/s11783-018-1029-8

摘要: Enteromorpha polysaccharide (Ep) extracted from alga a novel green coagulant aid for nanoparticles (NPs) and heavy metal ions removal and the structure of EP was intensively studied in this study. The integration of Ep with polyaluminum chloride (PAC-Ep) coagulants exhibited higher coagulation performance than that of the polyaluminum chloride (PAC) because of the negatively charged NPs suspension and humic aid (HA) solution. Significant high removal efficiencies of dissolved organic matter (94.1%), turbidity (99.3%) and Zn ions (69.3%) were achieved by the PAC-Ep coagulants. The dual-coagulation properties of PAC-Ep for different pollutants was based on multiple mechanisms, including (i) Al charge neutralization; (ii) hydroxy aluminum hydroxyl bridging formed polynuclearhydroxy complexes bridge and sweep colloidal particles; (iii) adsorption and bridging of Ep chain for the NPs and heavy metal ions. Results indicated that the destabilization of colloid was induced by the coexisting HA and higher removal was achieved as ions adsorption was enhance in the presence of HA complexation. On the basis of that, the extraction of polysaccharide is a promising candidate for its high coagulation performance in water treatment.

关键词: Algal Extraction     Enteromorpha polysaccharide     1H-13C nuclear magnetic resonance (NMR)     Fourier transform infrared (FTIR)     X-ray photoelectron spectroscopy (XPS)     Coagulation mechanism.    

从氢原子质子化模型计算H2<sup>+sup>的结构参数

陈景

《中国工程科学》 2004年 第6卷 第11期   页码 29-32

摘要:

对氢分子离子提出了氢原子质子化的结构模型,从微观时标和宏观时标分析了H2<sup>+sup>中库仑吸引力和两核排斥力的动态平衡,认为氢原子畸变后的电子云在两核中点产生e/8的电荷重心时可以束缚住一个裸质子;据此推导出键长、键能及力常数的计算公式;使用原子单位分别获得Re=2 au,De=0.109 735 au,k=0.109

关键词: 氢分子离子     键长     键能     力常数    

Precipitation study of CO

Siming Chen, Yue Wu, Geoffrey W. Stevens, Guoping Hu, Wenshou Sun, Kathryn A. Mumford

《化学科学与工程前沿(英文)》 2020年 第14卷 第3期   页码 415-424 doi: 10.1007/s11705-019-1882-4

摘要: Focused beam reflectance measurement (FBRM) and C nuclear magnetic resonance ( C NMR) analysis were used to study the precipitation process of CO -loaded potassium glycinate (KGLY) solutions at different CO loadings, during the addition of ethanol as an antisolvent at a rate of 10 mL·min . The volume ratio of ethanol added to the KGLY solution (3.0 mol·L , 340 mL) ranged from 0 to 3.0. Three solid-liquid-liquid phases were formed during the precipitation process. The FBRM results showed that the number of particles formed increased with CO loading and ethanol addition for CO -unsaturated KGLY solutions, whilst for CO -saturated KGLY solution it first increased then decreased to a stable value with ethanol addition. C NMR spectroscopic analysis showed that the crystals precipitated from the CO -unsaturated KGLY solutions consisted of glycine only, and the quantity crystallised increased with CO loading and ethanol addition. However, a complex mixture containing glycine, carbamate and potassium bicarbonate was precipitated from CO -saturated KGLY solution with the maximum precipitation percentages of 94.3%, 31.4% and 89.6%, respectively, at the ethanol volume fractions of 1.6, 2.5 and 2.3.

关键词: crystallization     precipitation     glycinate     FBRM     13C NMR    

Selective recovery of Cu

Haiping LUO,Bangyu QIN,Guangli LIU,Renduo ZHANG,Yabo TANG,Yanping HOU

《环境科学与工程前沿(英文)》 2015年 第9卷 第3期   页码 522-527 doi: 10.1007/s11783-014-0633-5

摘要: As the bioelectrochemical system, the microbial fuel cell (MFC) and the microbial electrolysis cell (MEC) were developed to selectively recover Cu and Ni ions from wastewater. The wastewater was treated in the cathode chambers of the system, in which Cu and Ni ions were removed by using the MFC and the MEC, respectively. At an initial Cu concentration of 500 mg·L , removal efficiencies of Cu increased from 97.0%±1.8% to 99.0%±0.3% with the initial Ni concentrations from 250 to 1000 mg·L , and maximum power densities increased from 3.1±0.5 to 5.4±0.6 W·m . The Ni removal mass in the MEC increased from 6.8±0.2 to 20.5±1.5 mg with the increase of Ni concentrations. At an initial Ni concentration of 500 mg·L , Cu removal efficiencies decreased from 99.1%±0.3% to 74.2%±3.8% with the initial Cu concentrations from 250 to 1000 mg·L , and maximum power densities increased from 3.0±0.1 to 6.3±1.2 W·m . Subsequently, the Ni removal efficiencies decreased from 96.9%±3.1% to 73.3%±5.4%. The results clearly demonstrated the feasibility of selective recovery of Cu and Ni from the wastewater using the bioelectrochemical system.

关键词: bioelectrochemical system     Cu2+     Ni2+     selective recovery    

新型400 km·h<sup>−1sup> 级架空接触网监测技术

Chul Jin Cho, Young Park

《工程(英文)》 2016年 第2卷 第3期   页码 360-365 doi: 10.1016/J.ENG.2016.03.016

摘要:

近年来,高速铁路各项技术不断发展,列车运行速度从300 km•h–1 提高到400 km•h<sup>−1sup>。本文介绍了由韩国研究者开发和论证的技术,即400 km•h<sup>−1sup> 级集电性能评估方法。

关键词: 高速铁路     架空接触网     状态监测     基于图像处理的测量方式    

配位不饱和Au-O-Ti<sup>3+sup>活性位点的构建及其在低温丙烯气相环氧化反应中强化氢气效率的研究 Article

宋钊宁, 闫昊, 袁俊聪, 马宏飞, 曹建琳, 王永祥, 王强, 彭冲, 邓风, 冯翔, 陈德, 杨朝合, 胡永康

《工程(英文)》 2023年 第25卷 第6期   页码 144-156 doi: 10.1016/j.eng.2023.01.008

摘要:

自1998年以来,人们广泛认为Au/Ti基催化剂的Au-O-Ti<sup>4+sup>位点是在相对高温条件下丙烯气相环氧化反应的活性位点,但该类催化剂的H2有效利用率普遍较低值得注意的是,该活性位点主导反应时,最佳温度可从200 °C显著降低至138 °C,并使催化剂保持前所未有的43.6%的H2有效利用率、90.7%的环氧丙烷(PO)选择性和超过100 h的稳定性。Ti<sup>3+sup>位点促进了Au和Ti<sup>3+sup>之间的电子转移,从而增强了催化剂对O2的吸附能力,有效促进H2O2H2有效利用率提供了新的思路,而且为低温下丙烯直接气相环氧化反应的工业化推进开辟了新的机会。

关键词: 丙烯环氧化     H2有效利用率     Au/Ti双功能催化剂     配位不饱和Ti位点     密度泛函理论    

NETO2 promotes melanoma progression via activation of the Ca/CaMKII signaling pathway

《医学前沿(英文)》 2023年 第17卷 第2期   页码 263-274 doi: 10.1007/s11684-022-0935-0

摘要: Melanoma is the most aggressive cutaneous tumor. Neuropilin and tolloid-like 2 (NETO2) is closely related to tumorigenesis. However, the functional significance of NETO2 in melanoma progression remains unclear. Herein, we found that NETO2 expression was augmented in melanoma clinical tissues and associated with poor prognosis in melanoma patients. Disrupting NETO2 expression markedly inhibited melanoma proliferation, malignant growth, migration, and invasion by downregulating the levels of calcium ions (Ca2+) and the expression of key genes involved in the calcium signaling pathway. By contrast, NETO2 overexpression had the opposite effects. Importantly, pharmacological inhibition of CaMKII/CREB activity with the CaMKII inhibitor KN93 suppressed NETO2-induced proliferation and melanoma metastasis. Overall, this study uncovered the crucial role of NETO2-mediated regulation in melanoma progression, indicating that targeting NETO2 may effectively improve melanoma treatment.

关键词: melanoma     neuropilin and tolloid-like 2     Ca2+/CaMKII signaling pathway    

Innate and adaptive T cells in influenza disease

null

《医学前沿(英文)》 2018年 第12卷 第1期   页码 34-47 doi: 10.1007/s11684-017-0606-8

摘要:

Influenza is a major global health problem, causing infections of the respiratory tract, often leading to acute pneumonia, life-threatening complications and even deaths. Over the last seven decades, vaccination strategies have been utilized to protect people from complications of influenza, especially groups at high risk of severe disease. While current vaccination regimens elicit strain-specific antibody responses, they fail to generate cross-protection against seasonal, pandemic and avian viruses. Moreover, vaccines designed to generate influenza-specific T-cell responses are yet to be optimized. During natural infection, viral replication is initially controlled by innate immunity before adaptive immune responses (T cells and antibody-producing B cells) achieve viral clearance and host recovery. Adaptive T and B cells maintain immunological memory and provide protection against subsequent infections with related influenza viruses. Recent studies also shed light on the role of innate T-cells (MAIT cells, gd T cells, and NKT cells) in controlling influenza and linking innate and adaptive immune mechanisms, thus making them attractive targets for vaccination strategies. We summarize the current knowledge on influenza-specific innate MAIT and gd T cells as well as adaptive CD8+ and CD4+ T cells, and discuss how these responses can be harnessed by novel vaccine strategies to elicit cross-protective immunity against different influenza strains and subtypes.

关键词: influenza     innate T cells     CD4+ and CD8+ T cells     vaccination    

动态二叉树表示环境的A<sup>*sup>算法及其在足球机器人路径规划中的实现

唐平,杨宜民

《中国工程科学》 2002年 第4卷 第9期   页码 50-53

摘要:

提出采用二叉树表示二维空间的方法,对全局路径规划和局部路径规划进行综合考虑,设计移动机器人在复杂环境下对动态障碍物进行避障的A<sup>*sup>算法。

关键词: 动态二叉树     A<sup>*sup>算法     路径规划    

Effect of noble metal nanoparticle size on C–N bond cleavage performance in hydrodenitrogenation: a study of active sites

《化学科学与工程前沿(英文)》 2023年 第17卷 第12期   页码 1986-2000 doi: 10.1007/s11705-023-2337-5

摘要: Breakage of the C–N bond is a structure sensitive process, and the catalyst size significantly affects its activity. On the active metal nanoparticle scale, the role of catalyst size in C–N bond cleavage has not been clearly elucidated. So, Ru catalysts with variable nanoparticle sizes were obtained by modulating the reduction temperature, and the catalytic activity was evaluated using 1,2,3,4-tetrahydroquinoline and o-propylaniline with different C–N bond hybridization patterns as reactants. Results showed a 13 times higher reaction rate for sp3-hybridized C–N bond cleavage than sp2-hybridized C–N bond cleavage, while the reaction rate tended to increase first and then decrease as the catalyst nanoparticle size increased. Different concentrations of terrace, step, and corner sites were found in different sizes of Ru nanoparticles. The relationship between catalytic site variation and C–N bond cleavage activity was further investigated by calculating the turnover frequency values for each site. This analysis indicates that the variation of different sites on the catalyst is the intrinsic factor of the size dependence of C–N bond cleavage activity, and the step atoms are the active sites for the C–N bond cleavage. When Ru nanoparticles are smaller than 1.9 nm, they have a strong adsorption effect on the reactants, which will affect the catalytic performance of the Ru catalyst. Furthermore, these findings were also confirmed on other metallic Pd/Pt catalysts. The role of step sites in C–N bond cleavage was proposed using the density function theory calculations. The reactants have stronger adsorption energies on the step atoms, and step atoms have d-band center nearer to the Fermi level. In this case, the interaction with the reactant is stronger, which is beneficial for activating the C–N bond of the reactant.

关键词: sp3/sp2-hybridized C–N bond     noble metal nanoparticle     catalytic active site     turnover frequency     DFT    

Clinical significance of CD34<sup>+sup>CD117<sup>dimsup>/CD34<sup>+sup>CD117<sup>brisup> myeloblast-associated

Xueping Li, Yuting Dai, Bing Chen, Jinyan Huang, Saijuan Chen, Lu Jiang

《医学前沿(英文)》 2021年 第15卷 第4期   页码 608-620 doi: 10.1007/s11684-021-0836-7

摘要: t(8;21)(q22;q22) acute myeloid leukemia (AML) is a highly heterogeneous hematological malignancy with a high relapse rate in China. Two leukemic myeloblast populations (CD34 CD117 and CD34 CD117 ) were previously identified in t(8;21) AML, and CD34 CD117 cell proportion was determined as an independent factor for this disease outcome. Here, we examined the impact of CD34 CD117 /CD34 CD117 myeloblast-associated gene expression on t(8;21) AML clinical prognosis. In this study, 85 patients with t(8;21) AML were enrolled. The mRNA expression levels of CD34 CD117 -associated genes ( , , and ) and CD34 CD117 -associated genes ( , , and ) were measured using quantitative reverse transcription PCR. Associations between gene expression and clinical outcomes were determined using Cox regression models. Results showed that patients with high , , or expression had significantly inferior overall survival (OS), whereas those with high or expression showed relatively favorable prognosis. Univariate analysis revealed that CD19, CD34 CD117 proportion, mutation, minimal residual disease (MRD), and expression levels of , , , and were associated with OS. Multivariate analysis indicated that mutation, MRD and and expression levels were independent prognostic variables for OS. Identifying the clinical relevance of CD34 CD117 /CD34 CD117 myeloblast-associated gene expression may provide new clinically prognostic markers for t(8;21) AML.

关键词: t(8     21)(q22     q22) AML     CD34+CD117dim/ CD34+CD117bri cell population     gene expression     prognosis    

K<sup>+sup> and Na<sup>+sup> fluxes in roots of two Chinese Iris populations

Pinfang LI,Biao ZHANG

《农业科学与工程前沿(英文)》 2014年 第1卷 第2期   页码 144-149 doi: 10.15302/J-FASE-2014016

摘要: Maintenance of ion homeostasis, particularly the regulation of K and Na uptake, is important for all plants to adapt to salinity. Observations on ionic response to salinity and net fluxes of K , Na in the root exhibited by plants during salt stress have highlighted the need for further investigation. The objectives of this study were to compare salt adaptation of two Chinese Iris ( Pall. var. (Fisch.) Koidz.) populations, and to improve understanding of adaptation to salinity exhibited by plants. Plants used in this study were grown from seeds collected in the Xinjiang Uygur Autonomous Region (Xj) and Beijing Municipality (Bj), China. Hydroponically-grown seedlings of the two populations were supplied with nutrient solutions containing 0.1 (control) and 140 mmol·L NaCl. After 12 days, plants were harvested for determination of relative growth rate and K , Na concentrations. Net fluxes of K , Na from the apex and along the root axis to 10.8 mm were measured using non-invasive micro-test technique. With 140 mmol·L NaCl treatment, shoots for population Xj had larger relative growth rate and higher K concentration than shoots for population Bj. However, the Na concentrations in both shoots and roots were lower for Xj than those for Bj. There was a lower net efflux of K found in population Xj than by Bj in the mature zone (approximately 2.4-10.8 mm from root tip). However, no difference in the efflux of Na between the populations was obtained. Population Xj of continued to grow normally under NaCl stress, and maintained a higher K /Na ratio in the shoots. These traits, which were associated with lower K leakage, help population Xj adapt to saline environments.

关键词: Iris lactea Pall. var. chinensis (Fisch.) Koidz     population     K+ and Na+     ion flux     non-invasive micro-test technique    

全氟化碳乳剂<sup>19sup>F磁共振成像的最新进展 Review

Anne H. Schmieder,Shelton D. Caruthers,Jochen Keupp,Samuel A. Wickline,Gregory M. Lanza

《工程(英文)》 2015年 第1卷 第4期   页码 475-489 doi: 10.15302/J-ENG-2015103

摘要:

<sup>19sup>F磁共振成像(MRI) 的研究可追溯到30多年前。在这30多年间,氢原子核(<sup>1sup>H)成像技术迅速发展,并在全球得到广泛应用,使得磁共振成像成为生物医学诊断成像技术中不可缺少的支柱。多年来,由于各种原因,对<sup>19sup>F成像技术的研究进展缓慢。但是在过去的十年间,尤其是最近几年,<sup>19sup>F成像的研究和临床相关性呈爆发式发展。部分原因归结为MRI仪器、<sup>19sup>F/<sup>1sup>H线圈设计以及临床前和临床核磁共振仪的超高速脉冲序列的发展。这些成就再加上对解剖生理学分子成像技术的兴趣以及一批创新造影剂的出现使<sup>19sup>F的概念进入了早期的临床评估中。

关键词:     磁共振成像(MRI)     双调线圈     全氟化碳     血管生成术     细胞标记    

Removal of ammonium and nitrate through Anammox and FeS-driven autotrophic denitrification

《环境科学与工程前沿(英文)》 2023年 第17卷 第6期 doi: 10.1007/s11783-023-1674-4

摘要:

● Simultaneous NH4+/NO3 removal was achieved in the FeS denitrification system

关键词: Anammox     Denitrification     FeS     NH4+/NO3     Sulfammox    

标题 作者 时间 类型 操作

Influence of short chain ceramides and lipophilic penetration enhancers on the nano-structure of stratum corneum model membranes studied using neutron diffraction

Annett SCHROETER, Tanja ENGELBRECHT, Reinhard H. H. NEUBERT

期刊论文

Application and mechanism of polysaccharide extracted from Enteromorpha to remove nano-ZnO and humic acid in coagulation process

Jianzhang Sun, Baoyu Gao, Yuanxia Luo, Moxi Xue, Xing Xu, Qinyan Yue, Yan Wang

期刊论文

从氢原子质子化模型计算H2<sup>+sup>的结构参数

陈景

期刊论文

Precipitation study of CO

Siming Chen, Yue Wu, Geoffrey W. Stevens, Guoping Hu, Wenshou Sun, Kathryn A. Mumford

期刊论文

Selective recovery of Cu

Haiping LUO,Bangyu QIN,Guangli LIU,Renduo ZHANG,Yabo TANG,Yanping HOU

期刊论文

新型400 km·h<sup>−1sup> 级架空接触网监测技术

Chul Jin Cho, Young Park

期刊论文

配位不饱和Au-O-Ti<sup>3+sup>活性位点的构建及其在低温丙烯气相环氧化反应中强化氢气效率的研究

宋钊宁, 闫昊, 袁俊聪, 马宏飞, 曹建琳, 王永祥, 王强, 彭冲, 邓风, 冯翔, 陈德, 杨朝合, 胡永康

期刊论文

NETO2 promotes melanoma progression via activation of the Ca/CaMKII signaling pathway

期刊论文

Innate and adaptive T cells in influenza disease

null

期刊论文

动态二叉树表示环境的A<sup>*sup>算法及其在足球机器人路径规划中的实现

唐平,杨宜民

期刊论文

Effect of noble metal nanoparticle size on C–N bond cleavage performance in hydrodenitrogenation: a study of active sites

期刊论文

Clinical significance of CD34<sup>+sup>CD117<sup>dimsup>/CD34<sup>+sup>CD117<sup>brisup> myeloblast-associated

Xueping Li, Yuting Dai, Bing Chen, Jinyan Huang, Saijuan Chen, Lu Jiang

期刊论文

K<sup>+sup> and Na<sup>+sup> fluxes in roots of two Chinese Iris populations

Pinfang LI,Biao ZHANG

期刊论文

全氟化碳乳剂<sup>19sup>F磁共振成像的最新进展

Anne H. Schmieder,Shelton D. Caruthers,Jochen Keupp,Samuel A. Wickline,Gregory M. Lanza

期刊论文

Removal of ammonium and nitrate through Anammox and FeS-driven autotrophic denitrification

期刊论文