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Improvement in the synthesis of 2-(5-amino-1,2,4-thiadiazol-3-yl)-2-(Z)-methoxyiminoacetic acid 2-benzothiazolyl

GAO Shihao, SUN Chenghui, ZHAO Xinqi, GAO Changquan

《化学科学与工程前沿（英文）》 2008年第2卷第1期页码 80-84 doi: 10.1007/s11705-008-0017-0

摘要： 2-(5-Amino-1,2,4-thiadiazol-3-yl)-2-(Z)-methoxyiminoacetic acid 2-benzothiazolyl thioester(III), an important intermediate of the fourth generation cephalosporins, was efficiently synthesized by reacting 2-(5-amino-1,2,4-thiadiazol-3-yl)-2-(Z)-methoxyiminoacetic acid (I) with 2,2′-dibenzothiazole disulfide (II) in the presence of triphenylphosphine. Effects of reaction time, temperature, solvents, catalysts and feeding molar ratio on the yield and quality of products were investigated, and an improved procedure suitable for industrial production was established. Using 1,2-dichloroethane as solvent, triphenylphosphine as reducer, and triethylamine as catalyst, (I) : (II) : (triphenylphosphine) = 1.0 : 1.0 : 1.0, the product was obtained at room temperature in 98.1% yield. The purity of the product without further purification is 98.7% determined by HPLC method. This procedure could be a suitable alternative to the traditional processes because of its easy handling, high yield and low cost.

关键词： 5-Amino-1 2 4-thiadiazol-3-yl 1 2-dichloroethane important intermediate 2-benzothiazolyl thioester temperature

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Controlled drug release of 5-amino salicylic acid by poly(2-hydroxyethylmethacrylate) grafted agar

G. Usha RANI,Kartick Prasad DEY,Srijita BHARTI,Sumit MISHRA

《化学科学与工程前沿（英文）》 2014年第8卷第4期页码 465-470 doi: 10.1007/s11705-014-1452-8

摘要： The utilization of poly (2-hydroxyethylmethacrylate) grafted agar (Ag-g-P(HEMA)) as a matrix for the controlled release of 5-aminosalicylic acid was investigated. Grafted copolymers of 2-hydroxyethylmethacrylate (HEMA) monomers on agar were synthesized by microwave assisted method. drug release studies were performed at pH values of 2 and 7 in order to investigate the possibility of pH triggered release for colon targeted drug delivery. Further, the percent grafting . (the time taken for release of 50% of the enclosed drug) value was studied and the results indicate that it may be possible to develop a programmable drug release matrix based on grafted polysaccharide. Ag-g-P(HEMA) appears to be a useful matrix for controlled release.

关键词： agar controlled drug release 5-Amino salicylic acid poly(2-hydroxyethylmethacrylate) grafted agar

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Encapsulation of 2-amino-2-methyl-1-propanol with tetraethyl orthosilicate for CO2 capture

Sidra Rama, Yan Zhang, Fideline Tchuenbou-Magaia, Yulong Ding, Yongliang Li

《化学科学与工程前沿（英文）》 2019年第13卷第4期页码 672-683 doi: 10.1007/s11705-019-1856-6

摘要： Carbon capture is widely recognised as an essential strategy to meet global goals for climate protection. Although various CO capture technologies including absorption, adsorption and membrane exist, they are not yet mature for post-combustion power plants mainly due to high energy penalty. Hence researchers are concentrating on developing non-aqueous solvents like ionic liquids, CO -binding organic liquids, nanoparticle hybrid materials and microencapsulated sorbents to minimize the energy consumption for carbon capture. This research aims to develop a novel and efficient approach by encapsulating sorbents to capture CO in a cold environment. The conventional emulsion technique was selected for the microcapsule formulation by using 2-amino-2-methyl-1-propanol (AMP) as the core sorbent and silicon dioxide as the shell. This paper reports the findings on the formulated microcapsules including key formulation parameters, microstructure, size distribution and thermal cycling stability. Furthermore, the effects of microcapsule quality and absorption temperature on the CO loading capacity of the microcapsules were investigated using a self-developed pressure decay method. The preliminary results have shown that the AMP microcapsules are promising to replace conventional sorbents.

关键词： carbon capture microencapsulated sorbents emulsion technique low temperature adsorption and absorption

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Catalytic conversion of biomass-derived compounds to various amino acids: status and perspectives

《化学科学与工程前沿（英文）》 2023年第17卷第7期页码 817-829 doi: 10.1007/s11705-022-2254-z

摘要： Amino acids are important nitrogen-containing chemicals that have a variety of applications. Currently, fermentation is the widely employed method to produce amino acids; however, the products are mostly limited to natural amino acids in the L-configuration. Catalytic synthesis is an alternative approach for the synthesis of amino acids with different types and configurations, where the use of renewable biomass-based feedstocks is highly attractive. To date, several lignocellulose and triacylglycerol-derived intermediates, typically α-keto acids and α-hydroxyl acids, have been transformed into amino acids via the amination reaction in the presence of additional nitrogen sources (i.e., NH₃·H₂O). Making full use of inherent nitrogen in biomass (i.e., chitin and protein) to produce amino acids avoids the use of extra nitrogen sources and meets the requirements of green chemistry, which is attracting increasing attention. In this review, we summarize different chemical-catalytic systems for the transformation of biomass to amino acids. An outlook on the challenges and opportunities for more effective production of amino acids from biomass by catalytic methods is provided.

关键词： biomass amino acids chitin nitrogen-containing compounds lignocellulose

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Novel variants in LAMA3 and COL7A1 and recurrent variant in KRT5 underlying epidermolysis bullosa in

《医学前沿（英文）》 2022年第16卷第5期页码 808-814 doi: 10.1007/s11684-021-0878-x

摘要： Epidermolysis bullosa (EB) is a group of clinically and genetically heterogeneous diseases characterized by trauma-induced mucocutaneous fragility and blister formation. Here, we investigated five Chinese families with EB, and eight variants including a novel nonsense variant (c.47G>A, p.W16*) in LAMA3, a known recurrent variant (c.74C>T, p.P25L) in KRT5, 2 novel (c.2531T>A, p.V844E; c.6811_6814del, p.R2271fs) and 4 known (c.6187C>T, p.R2063W; c.7097G>A, p.G2366D; c.8569G>T, p.E2857*; c.3625_3635del, p.S1209fs) variants in COL7A1 were detected. Notably, this study identified a nonsense variant in LAMA3 that causes EB within the Chinese population and revealed that this variant resulted in a reduction in LAMA3 mRNA and protein expression levels by nonsense-mediated mRNA decay. Our study expands the mutation spectra of Chinese patients with EB.

关键词： epidermolysis bullosa LAMA3 COL7A1 KRT5 Chinese families

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Netrin-1 works with UNC5B to regulate angiogenesis in diabetic kidney disease

Xiaojing Jiao, Dong Zhang, Quan Hong, Lei Yan, Qiuxia Han, Fengmin Shao, Guangyan Cai, Xiangmei Chen, Hanyu Zhu

《医学前沿（英文）》 2020年第14卷第3期页码 293-304 doi: 10.1007/s11684-019-0715-7

摘要： Netrin-1, an axon guidance factor, and its receptor UNC5B play important roles in axonal development and angiogenesis. This study examined netrin-1 and UNC5B expression in kidneys with diabetic kidney disease (DKD) and investigated their roles in angiogenesis. Netrin-1 and UNC5B were upregulated in streptozotocin-induced DKD Wistar rats, and their expression was compared with that in healthy controls. However, exogenous netrin-1 in UNC5B-depleted human renal glomerular endothelial cells (HRGECs) inhibited cell migration and tubulogenesis. This effect was likely associated with SRC pathway deactivation. Netrin-1 treatment also eliminated the pro-angiogenic effects of exogenous VEGF-165 on UNC5B-silenced HRGECs. These results indicate that UNC5B antagonizes netrin-1 and that UNC5B upregulation contributes partly to enhancing angiogenesis in DKD. Therefore, introducing exogenous netrin-1 and depleting endogenous UNC5B are potential strategies for reducing the incidence of early angiogenesis and mitigating kidney injury in DKD.

关键词： netrin-1 VEGF-165 UNC5B angiogenesis diabetic kidney disease

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纹理分支网络：基于超声影像的慢性肾脏病筛查模型 Research Articles

郝鹏翼1,5,徐震宇1,田树元2,吴福理1,5,陈为3,5,吴健4,5,罗笑南6

《信息与电子工程前沿（英文）》 2020年第21卷第8期页码 1119-1266 doi: 10.1631/FITEE.1900210

摘要：慢性肾脏病是一种在世界范围内广泛存在的肾脏疾病。该疾病一旦发展到晚期，伴随而来的是严重并发症与较高死亡风险。因此，早期筛查对于慢性肾脏病诊治至关重要。超声作为一种无创方法，能动态观察肾脏形态和病理特征，常用于肾脏检查。本文提出一种新的卷积神经网络模型，称为纹理分支网络，基于超声影像作慢性肾脏病筛查。该模型通过在经典卷积神经网络中引入纹理分支来提取和优化纹理特征，可自动生成输入图像的纹理特征和深度特征，并使用融合信息进行分类。此外，通过迁移学习训练网络的主干部分，并在具有226张超声影像的数据集上开展实验。实验结果表明，该模型准确率和敏感度分别达到96.01%和99.44%，在慢性肾脏病筛查上具有一定有效性。

关键词：慢性肾脏病；超声；纹理分支网络；迁移学习

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以“功能”储备补足“资源”储备——甲醇战略储备替代1/10~1/5的石油战略储备

金涌,陈丙珍

《中国工程科学》 2008年第10卷第11期页码 4-6

摘要：

对世界所有大国而言，石油战略储备是十分重要的。为了满足国家安全的需要，世界不同国际组织如联合国、欧盟等都建议设立3个月的石油战略储备。对于中国而言，这就需要战略储备石油3×10⁷~9×10⁷ t，这需要一个长时间段和大量资金注入才能完成。如果基于“功能”储备补足“资源”储备的一个新理念来思考，这一目标可以较容易地完成。即储备一定百分数的甲醇来替代石油，则国家安全也可以得到保障。

关键词：功能储备战略石油储备甲醇

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Endemicity of H9N2 and H5N1 avian influenza viruses in poultry in China poses a serious threat to poultry

Jiao HU,Xiufan LIU

《农业科学与工程前沿（英文）》 2016年第3卷第1期页码 11-24 doi: 10.15302/J-FASE-2016092

摘要： The H9N2 and H5N1 avian influenza viruses (AIVs) have been circulating in poultry in China and become endemic since 1998 and 2004, respectively. Currently, they are prevalent in poultry throughout China. This endemicity makes them actively involved in the emergence of the novel lineages of other subtypes of influenza viruses, such as the well-known viruses of the highly pathogenic avian influenza (HPAI) H5N2 and the 2013 novel H7N7, H7N9 and H10N8 subtypes, thereby threatening both the poultry industry and public health. Here, we will review briefly the prevalence and evolution, pathogenicity, transmission, and disease control of these two subtypes and also discuss the possibility of emergence of potentially virulent and highly transmissible AIVs to humans.

关键词： avian influenza virus H9N2 H5N1 novel viruses public health

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一种新型灰狼优化算法及其在5G频率选择表面设计中的应用 Research Article

何志豪1,2,3,晋刚1,2,3,王英俊1,2,3

《信息与电子工程前沿（英文）》 2022年第23卷第9期页码 1338-1353 doi: 10.1631/FITEE.2100580

摘要：第五代无线通信系统(5G)的发展使元启发算法与电磁设备的设计过程结合得更为紧密。本文提出一种自适应灰狼优化器（SAGWO），并将其与一种基于单元节点的5G频率选择面（FSS）优化模型相结合。在基准函数测试中，SAGWO优于其他5种优化算法：原始灰狼优化器（GWO）、遗传算法（GA）、粒子群优化器（PSO）、改进灰狼优化算法（IGWO）和基于选择性对抗的灰狼优化算法（SOGWO）。因为SAGWO具有良好全局寻优能力，所以SAGWO适用于解决具有较大设计空间的5G FSS优化问题。将SAGWO与新的FSS优化模型相结合，能自动生成在中心工作频率处具有电磁屏蔽能力的FSS结构。

关键词：灰狼优化算法；第五代无线通信系统（5G）；频率选择面；形状优化

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Unidirectional and stage-dependent roles of Notch1 in Wnt-responsive Lgr5

Hui Jiang, Shan Zeng, Wenli Ni, Yan Chen, Wenyan Li

《医学前沿（英文）》 2019年第13卷第6期页码 705-712 doi: 10.1007/s11684-019-0703-y

摘要： Wnt and Notch signaling play crucial roles in the determination of the prosensory domain and in the differentiation of hair cells (HCs) and supporting cells during mouse inner ear development; however, the relationship between the two signaling pathways in the mouse cochlea remains largely unknown. Here, we investigated the interactions between Notch and Wnt signaling on the basis of the bidirectional regulation of Notch1 specifically in Wnt-responsive Lgr5 progenitors during different cochlear development stages. We found that the downregulation of Notch1 in Lgr5 cells from embryonic day (E) 14.5 to E18.5 can drive the quiescent Lgr5 cells to re-enter the cell cycle and differentiate into extra HCs, whereas the upregulation of Notch1 expression did not affect the proliferation or differentiation of otic progenitor cells. No effect was observed on the upregulation or downregulation of Notch1 in Lgr5 cells from E10.5 to E14.5. We concluded that the roles of Notch1 in Wnt-responsive Lgr5 cells are unidirectional and stage dependent and Notch1 serves as a negative regulator for Lgr5 progenitor activation during cochlear differentiation. Our findings improved the understanding of the interactions between Notch and Wnt signaling in cochlear development.

关键词： inner ear cochlear Wnt Notch Lgr5 auditory system

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Insights into the changes of amino acids, microbial community, and enzymatic activities related with

《环境科学与工程前沿（英文）》 2023年第17卷第3期 doi: 10.1007/s11783-023-1635-y

摘要：

● The highest seed germination index was achieved at 0.3 g/g total solids of food waste.

关键词： Composting Food waste Amino acids Microbial community Enzymatic activity Nutrient quality

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一种用于5G金属边框智能手机的高隔离度耦合馈电模块 Correspondence

任爱娣1,余成苇1,杨利霞1,崔巍2,黄志祥1,刘英3

《信息与电子工程前沿（英文）》 2023年第24卷第11期页码 1657-1664 doi: 10.1631/FITEE.2300203

摘要：提出一款应用于第五代金属边框智能手机的高隔离度两天线模块。基于一个蚀刻在地板上的T形缝隙，通过合理地设计一个耦合馈电环天线和一个耦合馈电缝隙天线，实现了一款紧凑的两天线模块。尽管耦合馈电环天线和耦合馈电缝隙天线共口径，两者之间的隔离度高于30 dB。随后，通过集成4个两天线模块，实现了一款8×8多入多出系统。该系统实测互耦和包络相关系数分别小于−18.5 dB和0.02。

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Immobilization of penicillin G acylase onto amino-modified silica hydrogel

Weibing Dong, Huining HE, Junbo Gong, Victor C. YANG,

《化学科学与工程前沿（英文）》 2010年第4卷第1期页码 87-90 doi: 10.1007/s11705-009-0298-y

摘要： Amino-modified silica hydrogel (N-MSHG) was prepared by a simple sol-gel processing via the co-condensation of commercial silica sol with 3-aminopropyltrie-oxysilane. Penicillin G acylase (PGA), a model enzyme, was covalently immobilized onto the N-MSHG and then was used for the enzymatic synthesis of amoxicillin. The samples were characterized by Nitrogen sorption analysis, FT-IR and thermal gravimetric analysis (TGA). The results showed that the amino-modified gel was a mesoporous material with an average pore size of 12.64±0.17nm. The immobilization process was efficient and the immobilized enzyme showed high catalytic efficiency. The yield of the synthesis of amoxicillin in aqueous media was 38% for 2.5h. This sol-gel preparation is simple and shows prominent potential value in industrial processing.

关键词： gravimetric amino-modified efficient Amino-modified amoxicillin

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Insulin resistance and the metabolism of branched-chain amino acids

null

《医学前沿（英文）》 2013年第7卷第1期页码 53-59 doi: 10.1007/s11684-013-0255-5

摘要：

Insulin resistance (IR) is a key pathological feature of metabolic syndrome and subsequently causes serious health problems with an increased risk of several common metabolic disorders. IR related metabolic disturbance is not restricted to carbohydrates but impacts global metabolic network. Branched-chain amino acids (BCAAs), namely valine, leucine and isoleucine, are among the nine essential amino acids, accounting for 35% of the essential amino acids in muscle proteins and 40% of the preformed amino acids required by mammals. The BCAAs are particularly responsive to the inhibitory insulin action on amino acid release by skeletal muscle and their metabolism is profoundly altered in insulin resistant conditions and/or insulin deficiency. Although increased circulating BCAA concentration in insulin resistant conditions has been noted for many years and BCAAs have been reported to be involved in the regulation of glucose homeostasis and body weight, it is only recently that BCAAs are found to be closely associated with IR. This review will focus on the recent findings on BCAAs from both epidemic and mechanistic studies.

关键词： branched-chain amino acids leucine isoleucine valine insulin resistance