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Assessment of mobile and potential mobile trace elements extractability in calcareous soils using different extractingagents

Mohsen Jalali, Ziba Hurseresht

《环境科学与工程前沿(英文)》 2020年 第14卷 第1期 doi: 10.1007/s11783-019-1186-4

摘要: DTPA and NH4OAc, HNO3 and EDTA, and MgCl2 and NH4NO3 had similar behavior. In NH4OAc, DTPA, and EDTA, the possibility of re-adsorption of trace elements is low. CaCl2 may be more suitable than other extracts in calcareous soils. Understanding trace elements mobility in soils, extracting agents, and their relationships with soil components, are essential for predicting their movement in soil profile and availability to plants. A laboratory study was conducted to evaluate extractability of cadmium (Cd), cobalt (Co), copper (Cu), nickel (Ni), and zinc (Zn) from calcareous soils utilizing various extracting agents to be specific CaCl2, DTPA, EDTA, HNO3, MgCl2, NaNO3, NH4NO3, and NH4OAc. Cluster analysis indicated that DTPA and NH4OAc, HNO3 and EDTA, and MgCl2 and NH4NO3 extracting agents yielded comparative values, whereas NaNO3 and CaCl2 have shown different behavior than other extracting agents for all studied trace elements. The speciation of extracted trace elements in solutions indicated that in the CaCl2, NaNO3, NH4NO3, and MgCl2 extracting agents most extracted Cd, Co, Ni, Zn, and part of Cu were as free ions and may be re-adsorbed on soils, leading to lower extractability, whereas, in the case of HNO3 extracting agent, the likelihood of re-adsorption of trace elements may be little. The results of speciation of trace elements using NH4OAc, DTPA, and EDTA extracting agents showed that Me-(Acetate)3–, Me-(Acetate)2(aq), Me(DTPA)3−, Me(EDTA)2−, and MeH(EDTA)– complexes dominated in solutions indicating that the extracted trace elements may not be re-adsorbed on soils, leading to higher extractability. The results of this study are useful for short and long-term evaluations of trace elements mobility and further environmental impacts.

关键词: Mobility     Calcareous soils     Extracting agents     Trace elements    

Wavelet design for extracting weak fault feature based on lifting scheme

JIANG Hong-kai, WANG Zhong-sheng, HE Zheng-jia

《机械工程前沿(英文)》 2006年 第1卷 第2期   页码 199-203 doi: 10.1007/s11465-006-0009-z

摘要: Weak fault features of mechanical signals are usually immersed in noisy signals. A new wavelet method based on lifting scheme to match weak fault characteristics is proposed. In this method, an initial set of finite biorthogonal filters is modified by a lifting and dual lifting procedure alternately, and different lifting operators and dual lifting operators are obtained. The properties of the initial wavelet is improved, and the new wavelet with particular properties is designed. Simulation and engineering results confirm that the proposed method is better than other wavelet methods for extracting weak fault feature. Modulus maxima of the detail signal in every operation cycle are extracted, the position and time that weak signal singularity occurs are clearly found, and slight rub-impact fault caused by axis misalignment and rotor imbalance of a heavy oil catalytic cracking set are desirably extracted. extracted.

关键词: misalignment     imbalance     particular     position     mechanical    

Evaluation of 1,4-naphthoquinone derivatives as antibacterial agents: activity and mechanistic studies

《环境科学与工程前沿(英文)》 2023年 第17卷 第3期 doi: 10.1007/s11783-023-1631-2

摘要:

● All 1,4-naphthoquinone hybrids exhibited significant antimicrobial activity.

关键词: 1     4-naphthoquinone derivatives     Antibacterial     Action mechanism     RecA    

Technologies for extracting lipids from oleaginous microorganisms for biodiesel production

Cunwen WANG, Lu CHEN, Bajpai RAKESH, Yuanhang QIN, Renliang LV

《能源前沿(英文)》 2012年 第6卷 第3期   页码 266-274 doi: 10.1007/s11708-012-0193-y

摘要: Recently, biodiesel has received much more attention. Soybean oil, rapeseed oil, palm oil and corn oil are primary feedstock for biodiesel production. However, biodiesel production from these traditional oil-rich crops is limited by land availability, climate, and environmental and social issues regarding the use of feed and food crops for fuel. Oleaginous microorganisms, including microalgae, bacteria, yeast and fungi can be cultivated with high lipid contents and used as promising feedstock for biodiesel production. However, the high cost of biodiesel production using oil microorganisms has been the biggest obstacle for its industrialization. The process of biodiesel production from microorganisms involves many steps, of which the lipids extraction is the most important and costly. Therefore, searching for an effective and economical extraction system is critical. Various approaches of lipids extraction are discussed in this review, including traditional extraction procedures such as solvent extraction, pressing and solvent integrated extraction, as well as some new procedures.

关键词: oleaginous microorganisms     biodiesel     solvent extraction     ultrasound-assisted extraction     microwave-assisted extraction     supercritical fluid extraction (SFE)    

Animage-based approach to the reconstruction of ancient architectures by extracting and arranging 3D

Divya Udayan J,HyungSeok KIM,Jee-In KIM

《信息与电子工程前沿(英文)》 2015年 第16卷 第1期   页码 12-27 doi: 10.1631/FITEE.1400141

摘要: The objective of this research is the rapid reconstruction of ancient buildings of historical importance using a single image. The key idea of our approach is to reduce the infinite solutions that might otherwise arise when recovering a 3D geometry from 2D photographs. The main outcome of our research shows that the proposed methodology can be used to reconstruct ancient monuments for use as proxies for digital effects in applications such as tourism, games, and entertainment, which do not require very accurate modeling. In this article, we consider the reconstruction of ancient Mughal architecture including the Taj Mahal. We propose a modeling pipeline that makes an easy reconstruction possible using a single photograph taken from a single view, without the need to create complex point clouds from multiple images or the use of laser scanners. First, an initial model is automatically reconstructed using locally fitted planar primitives along with their boundary polygons and the adjacency relation among parts of the polygons. This approach is faster and more accurate than creating a model from scratch because the initial reconstruction phase provides a set of structural information together with the adjacency relation, which makes it possible to estimate the approximate depth of the entire structural monument. Next, we use manual extrapolation and editing techniques with modeling software to assemble and adjust different 3D components of the model. Thus, this research opens up the opportunity for the present generation to experience remote sites of architectural and cultural importance through virtual worlds and real-time mobile applications. Variations of a recreated 3D monument to represent an amalgam of various cultures are targeted for future work.

关键词: Digital reconstruction     3D virtual world     3D spatial components     Vision and scene understanding    

Novel lysosome-targeted anticancer fluorescent agents used in zebrafish and nude mouse tumour imaging

《化学科学与工程前沿(英文)》 2022年 第16卷 第1期   页码 112-120 doi: 10.1007/s11705-021-2075-5

摘要: The design of three novel fatty nitrogen mustard-based anticancer agents with fluorophores incorporated into the alkene structure (CXL 118, CXL121, and CXL122) is described in this report. The results indicated that these compounds are selectively located in lysosomes and exhibit effective antitumour activity. Notably, these compounds can directly serve as both reporting and imaging agents in vitro and in vivo without the need to add other fluorescent tagging agents.

关键词: fluorescent drug     lysosomal     anticancer     zebrafish     nude-mouse tumour imaging    

Comparison of masking agents for antimony speciation analysis using hydride generation atomic fluorescence

Jianhong XI,Mengchang HE,Kunpeng WANG,Guizhi ZHANG

《环境科学与工程前沿(英文)》 2015年 第9卷 第6期   页码 970-978 doi: 10.1007/s11783-014-0716-3

摘要: A sensitive atomic spectrometric method for the redox speciation analysis of Sb in water is described. The proposed method is based on the selective generation of stibine from Sb(III) in a continuous flow system using non-dispersive atomic fluorescence spectrometry for detection. The effects of the HCl concentration on the fluorescence intensities of Sb(III) and Sb(V) were investigated. The results indicated that atomic fluorescence emission due to Sb(V) can constructively interfere with the determination of Sb(III). For the determination of Sb(III), four compounds were tested as masking agents to inhibit the generation of stibine from Sb(V). The effects of the concentrations of the masking agents and of HCl on the fluorescence signals from Sb(III) and Sb(V) were studied. The results indicated that citric acid and NaF can successfully suppress hydride generation from Sb(V). To evaluate the developed methodology and the influence of the matrix, the recovery of Sb(III) from natural water that was spiked with different Sb(III) and Sb(V) concentrations was tested.

关键词: Sb(III)     Sb(V)     determination     masking agents     hydride generation (HG-AFS)    

Screening of textile finishing agents available on the Chinese market: An important source of per- and

Mehvish Mumtaz, Yixiang Bao, Wenchao Li, Lingxiao Kong, Jun Huang, Gang Yu

《环境科学与工程前沿(英文)》 2019年 第13卷 第5期 doi: 10.1007/s11783-019-1145-0

摘要: Kendrick mass defect was used for PFASs screening in textile finishing agents (TFAs). Total oxidizable precursor assay provides insight into unknown precursors. Perfluorooctane sulfonate was found as impurity in short ECF technology based TFAs. Perfluorooctanoate was also detected in C6 telomerization based TFAs. Long chain precursors were also observed in both types of TFAs. Organofluorinated surfactants are widely employed in textile finishing agents (TFAs) to achieve oil, water, and stain repellency. This has been regarded as an important emission source of per-and polyfluoroalkyl substances (PFASs) to the environment. China is the biggest manufacturer of clothes, and thus TFA production is also a relevant industrial activity. Nevertheless, to date, no survey has been conducted on PFAS contents in commercially available TFAs. In the present study, TFA products were investigated by the Kendrick mass defect method. The quantification results demonstrated a significant presence of perfluorooctane sulfonate (0.37 mg/L) in TFAs manufactured by electrochemical fluorination technology. The products obtained by short-chain PFAS-based telomerization were dominated by perfluorooctanoic acid (mean concentration: 0.29 mg/L), whose values exceeded the limits stated in the European Chemical Agency guidelines (0.025 mg/L). Moreover, the total oxidizable precursor assay indicated high levels of indirectly quantified precursors with long alkyl chains (C7–C9). Together, these results suggest that there is currently a certain of environmental and health risks in China that originates from the utilization of TFAs, and a better manufacturing processes are required to reduce such risks.

关键词: Textile finishing agents     Kendrick mass defect     Total oxidizable precursor assay    

Discovery of novel ursolic acid derivatives as effective antimicrobial agents through a ROS-mediated

《化学科学与工程前沿(英文)》 2023年 第17卷 第12期   页码 2101-2113 doi: 10.1007/s11705-023-2361-5

摘要: In response to the reduction of food production and economic losses caused by plant bacterial diseases, it is necessary to develop new, efficient, and green pesticides. Natural products are rich and sustainable source for the development of new pesticides due to their low toxicity, easy degradation, and eco-friendliness. In this study, we prepared three series of ursolic acid derivatives and assessed their antibacterial ability. Most target compounds exhibited outstanding antibacterial activities. Among them, the relative optimal EC50 values of Xanthomonas oryzae pv. oryzae and Xanthomonas axonopodis pv. citri were 2.23 (A17) and 1.39 (A16) μg·mL–1, respectively. The antimicrobial mechanism showed that compound A17 induced an excessive accumulation and production of reactive oxygen species in bacteria and damaged the cell membrane integrity to kill bacteria. More interestingly, the addition of low concentrations of exogenous hydrogen peroxide enhanced the antibacterial efficacy of compound A17 against Xanthomonas oryzae pv. oryzae. These entertaining results suggested that compound A17 induced an apparent apoptotic behavior in the tested bacteria. Overall, we developed the promising antimicrobial agents that destroyed the redox system of phytopathogenic bacteria, further demonstrating the unprecedented potential of ursolic acid for agricultural applications.

关键词: ursolic acid     antibacterial activities     reactive oxygen species     apoptosis    

Discovery of cryptolepine derivatives as novel promising agents against phytopathogenic bacteria

《化学科学与工程前沿(英文)》 2023年 第17卷 第2期   页码 156-166 doi: 10.1007/s11705-022-2196-5

摘要: To ensure the production of food crops, a series of cryptolepine derivatives were synthesised, after which their antibacterial activities and mechanism of action against three plant pathogens were investigated. Our bioassay results indicated that most of the target compounds displayed potent inhibitory effects against Xanthomonas oryzae (X. oryzae) and Xanthomonas axonopodis pv. citri (X. axonopodis pv. c.). Remarkably, compound 9 exhibited the best in vitro antibacterial activity against X. oryzae, with a minimum inhibitory concentration (MIC) value of 0.78 μg·mL–1. Compound 2 exhibited the best in vitro antibacterial activity against X. axonopodis pv. c., with an MIC value of 0.39 μg·mL–1. These activities were superior to those of copper quinolate (MIC = 6.25, 25 μg·mL–1) and thiodiazole copper (MIC = 100, 200 μg·mL–1) against X. oryzae and X. axonopodis pv. c. In vivo experiments demonstrated the promising applicability of compound 9 for the control of rice bacterial infections. Furthermore, compound 9 was selected as a candidate to conduct preliminary analyses of the antibacterial mechanisms of cryptolepine derivatives. Scanning electron microscopy and transmission electron microscopy observations, extracellular polysaccharide production, biofilm formation, transcriptomic, quantitative reverse transcription-polymerase chain reaction analyses, and molecular docking assays were performed. Collectively, our findings demonstrated that compound 9 might act via multifarious mechanisms to down-regulate virulence factors and cause cell death.

关键词: cryptolepine derivatives     phytopathogenic bacteria     antibacterial activity     mechanism of action    

BIOINSECTICIDES AS FUTURE MAINSTREAM PEST CONTROL AGENTS: OPPORTUNITIES AND CHALLENGES

《农业科学与工程前沿(英文)》 2022年 第9卷 第1期   页码 82-97 doi: 10.15302/J-FASE-2021404

摘要:

Bioinsecticides are naturally-occurring substances from different sources that control insect pests. Ideal bioinsecticides should have low toxicity to non-target organisms. They should also be easily degraded in sewage treatment works and natural environments, highly effective in small quantities and affect target pests only. Public concerns about possible side-effects of synthetic pesticides have accelerated bioinsecticide research and development. However, to develop bioinsecticides into mainstream products, their high production costs, short shelf-life and often uncertain modes of action need to be considered. This review summarizes current progress on bioinsecticides which are categorized as biochemical insecticides and their derivatives, plant-incorporated protectants, and microbial bioinsecticides. The current constraints that prevent bioinsecticides from being widely used are discussed and future research directions are proposed.

 

关键词: biochemical insecticide / bioinsecticide / microbial bioinsecticides / plant-incorporated protectant / RNA insecticide    

Antimicrobial activity of topical agents against Propionibacterium acnes: an in vitro study of clinical

null

《医学前沿(英文)》 2016年 第10卷 第4期   页码 517-521 doi: 10.1007/s11684-016-0480-9

摘要:

This study aimed to compare the antimicrobial activities of topical agents against Propionibacterium acnes isolated from patients admitted to a hospital in Shanghai, China. The minimal inhibitory concentrations of the cultured P. acnes were determined in accordance with the Clinical and Laboratory Standards Institute. Susceptibilities to clindamycin and erythromycin were compared in terms of gender, age, disease duration, previous treatment, and disease severity. A total of 69 P. acnes strains were isolated from 98 patients (70.41%). The susceptibility to triple antibiotic ointment (neomycin/bacitracin/polymyxin B) and bacitracin was 100%. The susceptibility to fusidic acid was 92.7%. The resistance rates to neomycin sulfate, erythromycin, and clindamycin were 11.7%, 49.3%, and 33.4%, respectively. The high resistance rate to clindamycin and erythromycin was significantly affected by gender, previous treatment, and disease severity rather than by age and disease duration. Topical antibiotics should not be used separately for long-term therapy to avoid multiresistance. The use of topical antibiotics should be determined by clinicians on the basis of clinical conditions.

关键词: antimicrobial susceptibility/resistance     Propionibacterium acnes     topical antibiotics     in vitro study    

Extracting terms from clinical records of traditional Chinese medicine

null

《医学前沿(英文)》 2014年 第8卷 第3期   页码 347-351 doi: 10.1007/s11684-014-0361-z

摘要:

Health records of traditional Chinese medicine contain valuable clinical information which can be used for improvement of disease treatment and for medical research. In this paper, we present a practical iterative extraction method for extracting terms from the records. The method is based on a set of extraction rules, the Mesh, and the likelihood ratio technique, and achieved a precision rate of 88.18% and a recall rate of 94.21%.

关键词: term extraction     rule-based     likelihood ratio    

Triterpenoid inducers of Nrf2 signaling as potential therapeutic agents in sickle cell disease: a review

null

《医学前沿(英文)》 2015年 第9卷 第1期   页码 46-56 doi: 10.1007/s11684-015-0375-1

摘要:

Sickle cell disease (SCD) is an inherited disorder of hemoglobin in which the abnormal hemoglobin S polymerizes when deoxygenated. This polymerization of hemoglobin S not only results in hemolysis and vaso-occlusion but also precipitates inflammation, oxidative stress and chronic organ dysfunction. Oxidative stress is increasingly recognized as an important intermediate in these pathophysiological processes and is therefore an important target for therapeutic intervention. The transcription factor nuclear erythroid derived- 2 related factor 2 (Nrf2) controls the expression of anti-oxidant enzymes and is emerging as a protein whose function can be exploited with therapeutic intent. This review article is focused on triterpenoids that activate Nrf2, and their potential for reducing oxidative stress in SCD as an approach to prevent organ dysfunction associated with this disease. A brief overview of oxidative stress in the clinical context of SCD is accompanied by a discussion of several pathophysiological mechanisms contributing to oxidative stress. Finally, these mechanisms are then related to current management strategies in SCD that are either utilized currently or under evaluation. The article concludes with a perspective on the potential of the various therapeutic interventions to reduce oxidative stress and morbidity associated with SCD.

关键词: oxidative stress     Nrf2     triterpenoids     sickle cell disease     vaso-occlusion     CDDO-Me    

Self-etching adhesives: possible new pulp capping agents to vital pulp therapy

null

《医学前沿(英文)》 2011年 第5卷 第1期   页码 77-79 doi: 10.1007/s11684-010-0104-8

摘要:

Pulp capping is one of the solving for keeping vital pulp in the case of dentin caries, reversible pulpitis or traumatic pulp exposure. The presence of bacteria on the cavity walls or in the pulp was the major factor that leads to the failure of pulp capping. Traditional pulp capping agent, calcium hydroxide, may not prevent microleakage. Self-etching system is a newly developed adhesive system, which could provide less microleakage and would not break down or dissolve, preventing the oral fluids and bacteria from the pulp along the cavity wall. This may reduce such clinical problems as postoperative sensitivity, secondary caries and marginal discoloration. Researches showed that some kinds of self-etching adhesives induced the mild to moderate inflammatory pulp response, with negative bacterial staining. Inclusion of antibacterial components into self-etching system, such as 12- methacryloyloxydodecylpyridinium bromide (MDPB) may inhibit bacteria and provide better clinical effects. It is speculated that using the self-etching adhesive system containing the antibacterial agent, such as MDPB, to the dental pulp directly or indirectly, may inhibit bacteria after the placement of restoration as well as residual bacteria in the cavity.

关键词: dental pulp     pulp capping     self-etching adhesives     antibacterial components    

标题 作者 时间 类型 操作

Assessment of mobile and potential mobile trace elements extractability in calcareous soils using different extractingagents

Mohsen Jalali, Ziba Hurseresht

期刊论文

Wavelet design for extracting weak fault feature based on lifting scheme

JIANG Hong-kai, WANG Zhong-sheng, HE Zheng-jia

期刊论文

Evaluation of 1,4-naphthoquinone derivatives as antibacterial agents: activity and mechanistic studies

期刊论文

Technologies for extracting lipids from oleaginous microorganisms for biodiesel production

Cunwen WANG, Lu CHEN, Bajpai RAKESH, Yuanhang QIN, Renliang LV

期刊论文

Animage-based approach to the reconstruction of ancient architectures by extracting and arranging 3D

Divya Udayan J,HyungSeok KIM,Jee-In KIM

期刊论文

Novel lysosome-targeted anticancer fluorescent agents used in zebrafish and nude mouse tumour imaging

期刊论文

Comparison of masking agents for antimony speciation analysis using hydride generation atomic fluorescence

Jianhong XI,Mengchang HE,Kunpeng WANG,Guizhi ZHANG

期刊论文

Screening of textile finishing agents available on the Chinese market: An important source of per- and

Mehvish Mumtaz, Yixiang Bao, Wenchao Li, Lingxiao Kong, Jun Huang, Gang Yu

期刊论文

Discovery of novel ursolic acid derivatives as effective antimicrobial agents through a ROS-mediated

期刊论文

Discovery of cryptolepine derivatives as novel promising agents against phytopathogenic bacteria

期刊论文

BIOINSECTICIDES AS FUTURE MAINSTREAM PEST CONTROL AGENTS: OPPORTUNITIES AND CHALLENGES

期刊论文

Antimicrobial activity of topical agents against Propionibacterium acnes: an in vitro study of clinical

null

期刊论文

Extracting terms from clinical records of traditional Chinese medicine

null

期刊论文

Triterpenoid inducers of Nrf2 signaling as potential therapeutic agents in sickle cell disease: a review

null

期刊论文

Self-etching adhesives: possible new pulp capping agents to vital pulp therapy

null

期刊论文