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

《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

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从氢原子质子化模型计算H₂+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>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R_e=2 au，D_e=0.109 735 au，k=0.109

关键词：氢分子离子键长键能力常数

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Symbiotic performance, shoot biomass and water-use efficiency of three groundnut (

Sofiya K. MUHABA, Felix D. DAKORA

《农业科学与工程前沿（英文）》 2020年第7卷第4期页码 455-466 doi: 10.15302/J-FASE-2020354

摘要：

Phosphorus is a key nutrient element involved in energy transfer for cellular metabolism, respiration and photosynthesis and its supply at low levels can affect legume nodulation, N fixation, and C assimilation. A two-year field study was conducted in Ethiopia in 2012 and 2013 to evaluate the effects of P supply on growth, symbiotic N nutrition, grain yield and water-use efficiency of three groundnut genotypes. Supplying P to the genotypes significantly increased their shoot biomass, symbiotic performance, grain yield, and C accumulation. There was, however, no effect on shoot δ C values in either year. Compared to the zero-P control, supplying 40 kg·ha P markedly increased shoot biomass by 77% and 66% in 2012 and 2013, respectively. In both years, groundnut grain yields were much higher at 20 and 30 kg·ha P. Phosphorus supply markedly reduced shoot δ N values and increased the %Ndfa and amount of N-fixed, indicating the direct involvement of P in promoting N fixation in nodulated groundnut. The three genotypes differed significantly in δ N, %Ndfa, N-fixed, grain yield, C concentration, and δ C. The phosphorus × genotype interaction was also significant for shoot DM, N content, N-fixed and soil N uptake.

关键词： shoot yield N-fixed %Ndfa δ¹⁵N δ¹³C water-use efficiency

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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

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动态二叉树表示环境的A*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>算法。

关键词：动态二叉树 A*sup>算法路径规划

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Clinical significance of CD34+sup>CD117dimsup>/CD34+sup>CD117brisup> 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⁺CD117^dim/ CD34⁺CD117^bri cell population gene expression prognosis

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K+sup> and Na+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

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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

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An electrochemical process that uses an Fe

Chaojie Jiang, Lifen Liu, John C. Crittenden

《环境科学与工程前沿（英文）》 2016年第10卷第4期 doi: 10.1007/s11783-016-0860-z

摘要： A bio-electrochemical fuel cell reactor with cathodic Fe /TiO generates electricity. It destroys recalcitrant pollutants in cathode chamber without photocatalysis. Fe /TiO generates reactive oxygenated species in the dark or under photocatalysis. Cathodic produced ROS (hydroxy radical/superoxide radical) can degrade tetracycline or dyes. Electricity generation is enhanced by semiconductor catalyzed cathodic degradation of pollutants. In this study, a new water treatment system that couples (photo-) electrochemical catalysis (PEC or EC) in a microbial fuel cell (MFC) was configured using a stainless-steel (SS) cathode coated with Fe /TiO . We examined the destruction of methylene blue (MB) and tetracycline. Fe /TiO was prepared using a chemical reduction-deposition method and coated onto an SS wire mesh (500 mesh) using a sol technique. The anode generates electricity using microbes (bio-anode). Connected via wire and ohmic resistance, the system requires a short reaction time and operates at a low cost by effectively removing 94% MB (initial concentration 20 mg·L ) and 83% TOC/TOC under visible light illumination (50 W; 1.99 mW·cm for 120 min, MFC-PEC). The removal was similar even without light irradiation (MFC-EC). The of the MFC-PEC system was approximately 0.675 kWh·m ·order , whereas that of the MFC-EC system was zero. The system was able to remove 70% COD in tetracycline solution (initial tetracycline concentration 100 mg·L ) after 120 min of visible light illumination; without light, the removal was 15% lower. The destruction of MB and tetracycline in both traditional photocatalysis and photoelectrocatalysis systems was notably low. The electron spin-resonance spectroscopy (ESR) study demonstrated that ·OH was formed under visible light, and ·O was formed without light. The bio-electricity-activated O and ROS (reactive oxidizing species) generation by Fe /TiO effectively degraded the pollutants. This cathodic degradation improved the electricity generation by accepting and consuming more electrons from the bio-anode.

关键词： Bio-anode Photocatalytic cathode Fe⁰/TiO₂ ESR Dye and antibiotics Advanced oxidation

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以NH₃OH+sup>/NH₂NH₃+sup>作为B位阳离子的无金属六方钙钛矿含能材料 Article

尚宇, 余志鸿, 黄瑞康, 陈劭力, 刘德轩, 陈晓娴, 张伟雄, 陈小明

《工程（英文）》 2020年第6卷第9期页码 1013-1018 doi: 10.1016/j.eng.2020.05.018

摘要：文中通过合理地选择分子组分，经由易于规模放大的简单合成路线，以NH₃OH+sup>和NH₂NH₃+sup>分别作为B位点阳离子构筑了两例无金属六方钙钛矿含能材料(H₂dabco)B(ClO₄)₃（分别命名为DAP-6和DAP-7，其中H₂dabco2+sup>是1,4-二氮杂双环[2.2.2]辛烷-1,4-二鎓离子）。>_sp= 265.3 s）均稍优于六硝基六氮杂异伍兹烷（CL-20：Q = 6.23 kJ·g‒1sup>，I_sp = 264.8 s），在炸药和推进剂领域中具有很好的应用前景。

关键词：含能材料单质炸药固体推进剂无金属六方钙钛矿

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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

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Effects of La, Ce on nitrogen removal in sequencing batch reactor

Qing XIA , Rui LIANG , Yuning HONG , Lili DING , Hongqiang REN , Yuxiang MAO , Mingyu ZHAO ,

《环境科学与工程前沿（英文）》 2009年第3卷第3期页码 369-374 doi: 10.1007/s11783-009-0036-1

摘要： Batch experiments were conducted to study the short-term biological effects of rare earth ions (La, Ce) and their mixture on the nitrogen removal in a sequencing batch reactor (SBR). The data showed that higher NH―N removal rate, total inorganic nitrogen removal efficiency, and denitrification efficiency were achieved at lower concentrations of rare earth elements (REEs) (<1mg/L). In the first hour of the aeration stage of SBR, the presence of REEs increased the total inorganic nitrogen removal efficiency and NH―N removal efficiency by 15.7% and 10%―15%, respectively. When the concentrations of REEs were higher than 1mg/L, the total inorganic nitrogen removal efficiency decreased, and nitrate was found to accumulate in the effluent. When the concentrations of REEs was up to 50.0mg/L, the total inorganic nitrogen removal efficiency was less than 30% of the control efficiency with a high level of nitrate. Lower concentrations of REEs were found to accelerate the nitrogen conversion and removal in SBR.

关键词： rare earth La³⁺ Ce³⁺ inorganic nitrogen nitrogen removal sequencing batch reactor

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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

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Advances of 12thsup> CAPS research symposium: young chemists and chemical engineers fronts

Guoping Hu, Baiqian Dai

《化学科学与工程前沿（英文）》 2021年第15卷第3期页码 461-463 doi: 10.1007/s11705-020-2026-6

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RNA m6sup>A modification and its function in diseases

null

《医学前沿（英文）》 2018年第12卷第4期页码 481-489 doi: 10.1007/s11684-018-0654-8

摘要：

N⁶-methyladenosine (m⁶A) is the most common post-transcriptional RNA modification throughout the transcriptome, affecting fundamental aspects of RNA metabolism. m⁶A modification could be installed by m⁶A “writers” composed of core catalytic components (METTL3/METTL14/WTAP) and newly defined regulators and removed by m⁶A “erasers” (FTO and ALKBH5). The function of m⁶A is executed by m⁶A “readers” that bind to m⁶A directly (YTH domain-containing proteins, eIF3 and IGF2BPs) or indirectly (HNRNPA2B1). In the past few years, advances in m⁶A modulators (“writers,” “erasers,” and “readers”) have remarkably renewed our understanding of the function and regulation of m⁶A in different cells under normal or disease conditions. However, the mechanism and the regulatory network of m⁶A are still largely unknown. Moreover, investigations of the m⁶A physiological roles in human diseases are limited. In this review, we summarize the recent advances in m⁶A research and highlight the functional relevance and importance of m⁶A modification in in vitro cell lines, in physiological contexts, and in cancers.