Electrocatalytic water splitting has been identified as a potential candidate for producing clean hydrogen energy with zero carbon emission.However,the sluggish kinetics of oxygen evolution reaction on the anode side ...Electrocatalytic water splitting has been identified as a potential candidate for producing clean hydrogen energy with zero carbon emission.However,the sluggish kinetics of oxygen evolution reaction on the anode side of the watersplitting device significantly hinders its practical applications.Generally,the efficiency of oxygen evolution processes depends greatly on the availability of cost‐effective catalysts with high activity and selectivity.In recent years,extensive theoretical and experimental studies have demonstrated that cobalt(Co)‐based nanomaterials,especially low‐dimensional Co‐based nanomaterials with a huge specific surface area and abundant unsaturated active sites,have emerged as versatile electrocatalysts for oxygen evolution reactions,and thus,great progress has been made in the rational design and synthesis of Co‐based nanomaterials for electrocatalytic oxygen evolution reactions.Considering the remarkable progress in this area,in this timely review,we highlight the most recent developments in Co‐based nanomaterials relating to their dimensional control,defect regulation(conductivity),electronic structure regulation,and so forth.Furthermore,a brief conclusion about recent progress achieved in oxygen evolution on Co‐based nanomaterials,as well as an outlook on future research challenges,is given.展开更多
In a task-based communicative classroom, group activities are effective ways to devdop students' 4 basic language skills. However, not all group activities can reach the expected results. English teachers should p...In a task-based communicative classroom, group activities are effective ways to devdop students' 4 basic language skills. However, not all group activities can reach the expected results. English teachers should pay attention to some aspects in organizing a classroom group activity.展开更多
In English reading, teachers should take students as the main body by creating situations, putting forward tasks,practicing interaction and evaluating teachers and students according to the corresponding classroom goa...In English reading, teachers should take students as the main body by creating situations, putting forward tasks,practicing interaction and evaluating teachers and students according to the corresponding classroom goals so as to improve students' English reading skills and the comprehensive use of language ability. Effective reading activities can help improve students' English level at different English reading stages,such as pre-reading stage,w hile-reading stage, post-reading stage.展开更多
The genus Populus has long been used for environmental,agroforestry and industrial applications worldwide.Today Populus is also recognized as a desirable crop for biofuel production and a model tree for physiological ...The genus Populus has long been used for environmental,agroforestry and industrial applications worldwide.Today Populus is also recognized as a desirable crop for biofuel production and a model tree for physiological and ecological research.As such,various modern biotechnologies,including CRISPR/Cas9-based techniques,have been actively applied to Populus for genetic and genomic improvements for traits such as increased growth rate and tailored lignin composition.However,CRISPR/Cas9 has been primarily used as the active Cas9 form to create knockouts in the hybrid poplar clone“717-1B4”(P.tremula x P.alba clone INRA 717-1B4).Alternative CRISPR/Cas9-based technologies,e.g.those involving modified Cas9 for gene activation and base editing,have not been evaluated in most Populus species for their efficacy.Here we employed a deactivated Cas9(dCas9)-based CRISPR activation(CRISPRa)technique to fine-tune the expression of two target genes,TPX2 and LecRLK-G which play important roles in plant growth and defense response,in hybrid poplar clone“717-1B4”and poplar clone“WV94”(P.deltoides“WV94”),respectively.We observed that CRISPRa resulted in 1.2-fold to 7.0-fold increase in target gene expression through transient expression in protoplasts and Agrobacterium-mediated stable transformation,demonstrating the effectiveness of dCas9-based CRISPRa system in Populus.In addition,we applied Cas9 nickase(nCas9)-based cytosine base editor(CBE)to precisely introduce premature stop codons via C-to-T conversion,with an efficiency of 13%–14%,in the target gene PLATZ which encodes a transcription factor involved in plant fungal pathogen response in hybrid poplar clone“717-1B4”.Overall,we showcase the successful application of CRISPR/Cas-based technologies in gene expression regulation and precise gene engineering in two Populus species,facilitating the adoption of emerging genome editing tools in woody species.展开更多
<span style="font-family:Verdana;">Three Schiff bases L</span><sub><span style="font-family:Verdana;">1</span></sub><span style="font-family:Verdana;&quo...<span style="font-family:Verdana;">Three Schiff bases L</span><sub><span style="font-family:Verdana;">1</span></sub><span style="font-family:Verdana;">, L</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> and L</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;"> were synthesized by condensing salicylalde</span><span style="font-family:Verdana;">hyde with 4-aminoantipyrine, ethylendiamine and 2-aminophenol respec</span><span style="font-family:Verdana;">tively and subsequently characterized by various physicochemical investigations. All the three compounds were screened for their </span><i><span style="font-family:Verdana;">In-vitro</span></i><span style="font-family:Verdana;"> antibacterial activity against two gram positive bacteria, </span><i><span style="font-family:Verdana;">Staphylococcus aureus</span></i><span style="font-family:Verdana;"> (S.A), </span><i><span style="font-family:Verdana;">Staphylococcus epidermidis</span></i><span style="font-family:Verdana;"> (S.E) and two gram negative bacteria </span><i><span style="font-family:Verdana;">Klebsiella</span></i><span><span><i><span style="font-family:""> </span></i></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;">pneumoniae</span></i></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;"> (K.P) and </span><i><span style="font-family:Verdana;">Pseudomonas aeruginosa </span></i><span style="font-family:Verdana;">(</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">P.</span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">A) by agar diffusion method. On comparing the results obtained with the activity of commercially available antibiotics such as Ciprofloxacin and Chloramphenicol, the newly synthesized compounds showed comparable antibacterial activities. The solvent methanol exhibit activity against all bacterial species with IZs ranging from 8 ± 0.25 to 17 ± 0.29 mm while the standard antibiotics Ciprofloxacin and Chloramphenicol exhibited an activities with IZs varying from 21.3 ± 0.31 to 28.3 ± 0.32 and 26.3 ± 0.24 mm to 32.3 ± 0.23 mm, respectively. However, the newly synthesized Schiff bases L</span><sub><span style="font-family:Verdana;">1</span></sub><span style="font-family:Verdana;">, L</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> and L</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;"> showed IZs ranging from 7.4 ± 0.23 to 32.5 ± 0.14, 3 ± 0.57 to 12 ± 0.28 and 10 ± 0.20 to 32 ± 0.36 respectively. Among the Schiff bases, L</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;"> showed the activity (32 ± 0.36) against S.E and P.A </span><span style="font-family:Verdana;">which is higher than the activity of standard antibiotics Ciprofloxacin and</span><span style="font-family:Verdana;"> Chloramphenicol against the same bacterial strains. The results obtained revealed that all the synthesized Schiff bases exhibit appreciable antibacterial activity against all the bacteria species which potentially makes them, to apply as wide range antibacterial drugs, after further </span><i><span style="font-family:Verdana;">in-vivo</span></i><span style="font-family:Verdana;"> cytotoxicity investigations. Their activity can also be further modified by changing the functionality of precursors for Schiff base condensation.</span></span></span></span>展开更多
Aphasia is a higher brain dysfunction that affects the production or comprehension of speech and the ability to read or write. The purpose of this research is to establish support guidelines based on a questionnaire s...Aphasia is a higher brain dysfunction that affects the production or comprehension of speech and the ability to read or write. The purpose of this research is to establish support guidelines based on a questionnaire survey and a language activity analysis of rehabilitation training so that volunteers can more easily assist disabled persons with aphasia. The focus of this study was the non-profit community-based intervention group Yokohama Aphasia Partner Group, which consists of members with aphasia, their families, speech-language-and-hearing therapists, psychiatric social workers, and volunteers. The following results were obtained. (1) Members with aphasia participate in the Partner Group because they can meet others with aphasia on a regular basis as well as participate in the aphasia rehabilitation program with the recovery of language functions. In addition to medical treatment, the community-based support, which improves the environment and other life contextual factors, is important for rehabilitation. (2) An individual with aphasia shows different language actions, and so an individually different support system in accordance with language activity is necessary.展开更多
This paper focuses on a beginner adult ESL classroom aiming to enhance their participation under the guidance of“taskbased teaching”method. By incorporating three strategies of priming students to elicit their prior...This paper focuses on a beginner adult ESL classroom aiming to enhance their participation under the guidance of“taskbased teaching”method. By incorporating three strategies of priming students to elicit their prior knowledge on certain topic, designing a sequence of tasks to scaffold students for the final produce and modelling with lower level students to ensure their under? standing of task instructions, the activeness could see a significant increase.展开更多
Activity based costing (ABC) is a method which can solve many limitations of the traditional cost systems in manufacturing management. In this paper, we investigate how to integrate ABC with workflow technology, and ...Activity based costing (ABC) is a method which can solve many limitations of the traditional cost systems in manufacturing management. In this paper, we investigate how to integrate ABC with workflow technology, and build a workflow meta model supporting ABC. Firstly, the concept and concept model of activity based costing (ABC) are introduced. Next, the meta model of P -PROCE (Process, Product, Resource, Organization, and Cost & Evaluation) is presented. Then the cost meta model is defined by adding ABC to P -PROCE model. Object constraint language (OCL) is used to express meta model and constraints. Finally, we show an enterprise modeling and simulation tool based on the workflow meta model. We can systematically construct an enterprise model and easily and efficiently conduct simulation. Moreover it enables us to analyze and evaluate business processes and its costs.展开更多
This study focuses on the effectiveness of the project-based language learning(PBLL) in a college Secretarial Oral English(SOE) Module. Student reflections of the language project work have been analyzed through Activ...This study focuses on the effectiveness of the project-based language learning(PBLL) in a college Secretarial Oral English(SOE) Module. Student reflections of the language project work have been analyzed through Activity Theory. Moreover,Data has been collected and categorized based on the components of complex human activity: the subject, object, tools(signs,symbols, and language), the community in which the activity take place, division of labor, and rules. The findings theoretically support the outcome of project-based language learning which align with the object of the activity.展开更多
Based on several books on English teaching and learning,this paper gives a general review on task-based teaching.Firstly,it introduces the definitions of task and task-based syllabus and makes two distinctions,namely,...Based on several books on English teaching and learning,this paper gives a general review on task-based teaching.Firstly,it introduces the definitions of task and task-based syllabus and makes two distinctions,namely,"task"and"activity","taskbased teaching"and"communicative teaching".Then it states the notions behind the task-based teaching.Finally,it gives the notes for the application of this approach.展开更多
A complex [NIL2] was synthesized, in which L, or to be exact, a Schiff base ligand (HL), was derived from the condensation of 1-phenyl-3-methyl-4-phenylacetyl-5-pyrazolone (PMPAP) with L-phenylalanine methyl ester...A complex [NIL2] was synthesized, in which L, or to be exact, a Schiff base ligand (HL), was derived from the condensation of 1-phenyl-3-methyl-4-phenylacetyl-5-pyrazolone (PMPAP) with L-phenylalanine methyl ester. They were characterized by IR and single-crystal X-ray diffraction. Green block crystals of both ligand and its complex were grown at room temperature. The ligand, which consists of two individual fragments, crystalizes in the P1 space group (a = 5.6268(5), b = 10.6892(11) and c = 19.4869(18) A). The complex crystalizes in the P21 space group (a -- 21.4076(18), b = 9.4792(8) and c = 25.287(2) A), which consists of a nickel six-coordinated compound. Every fragment is a distorted octahedron with four oxygen and two nitrogen atoms. The Schiff base ligand (HL) and its complex have been tested in vitro to evaluate their antibacterial activity against bacteria Escherichia Coli and Bacillus subtilis. It is found that the complex has higher activity than the corresponding free Schiff base ligand (HL) against the same bacterial.展开更多
Base isolated structures have been found to be at risk in near-fault regions as a result of long period pulses that may exist in near-source ground motions. Various control strategies, including passive, active and se...Base isolated structures have been found to be at risk in near-fault regions as a result of long period pulses that may exist in near-source ground motions. Various control strategies, including passive, active and semi-active control systems, have been investigated to overcome this problem. This study focuses on the development of a semi-active control algorithm based on several performance levels anticipated from an isolated building during different levels of ground shaking corresponding to various earthquake hazard levels. The proposed performance-based algorithm is based on a modified version of the well-known semi-active skyhook control algorithm. The proposed control algorithm changes the control gain depending on the level of shaking imposed on the structure. The proposed control system has been evaluated using a series of analyses performed on a base isolated benchmark building subjected to seven pairs of scaled ground motion records. Simulation results show that the newly proposed algorithm is effective in improving the structural and nonstructural performance of the building for selected earthquakes.展开更多
Two new zinc(Ⅱ) complexes, [Zn2L2Ch].2[ZnL(CH3OH)Cl2] 1 and [ZnL2(NO3)2] 2, were synthesized by reacting ZnX2.nH2O (X = Cl^-, NO3^-) and a Schiff base ligand 2-[(4-methylphenylimino)methyl]-6-methoxyphenol ...Two new zinc(Ⅱ) complexes, [Zn2L2Ch].2[ZnL(CH3OH)Cl2] 1 and [ZnL2(NO3)2] 2, were synthesized by reacting ZnX2.nH2O (X = Cl^-, NO3^-) and a Schiff base ligand 2-[(4-methylphenylimino)methyl]-6-methoxyphenol (C15HIsNO2, L) which was obtained by the condensation of o-vanillin (2-hydroxy-3-methoxybenzaldehyde) with p-toluidine. Both 1 and 2 were characterized by single-crystal X-ray diffraction technique, elemental analysis, molar conductance, FT-IR, UV-Vis, IH-NMR spectra and thermogravimetrie analysis. The Schiff base ligand and its zinc(Ⅱ) complexes have been tested in vitro to evaluate their antibacterial activity against bacteria, viz., Escherichia Coli, Staphylococcus aureus and Bacillus Subtilis. The results show that these complexes have higher activity than the corresponding free Schiff base ligand against the same bacteria.展开更多
Two heterocyclic Schiff bases were synthesized via the condensation reactions of primary amines with carbonyl compounds. 2-[(4-pyridylmethylene)-amino] phenol (compound 1) was synthesized by the interaction of 4-p...Two heterocyclic Schiff bases were synthesized via the condensation reactions of primary amines with carbonyl compounds. 2-[(4-pyridylmethylene)-amino] phenol (compound 1) was synthesized by the interaction of 4-pyridinecarboxaldehyde with o-aminophenol in ethanol solvent; N,N'-bis(3-(furan-2-yl)allylidene)benzene-1,4-diamin (compound 2) was synthesized by the interaction of 3-(2-furyl)acrolein with p-phenylenediamine in ethanol medium. The compounds were characterized by elemental analysis, IR, MS and single-crystal X-ray diffraction. Compound 1 (C12H10N2O) crystallizes in the monoclinic system, space group P21/c with α = 7.0771(7), b = 7.2820(7), c = 19.849(2), b = 96.3390(10)°, V = 1016.66(17) ?3, Z = 4, Mr = 198.22, Dc = 1.295 g/cm3, F(000) = 416, GOOF = 1.060, m = 0.085 mm-1, the final R = 0.0371 and wR = 0.0929 for 1497 observed reflections with I 〉 2σ(I). Compound 2 (C20H16N2O2) crystallizes in the orthorhombic system, space group Fdd2 with α = 26.344(15), b = 48.50(3), c = 5.293(3), V = 6764(7) ?3, Z = 16, Mr = 316.35, Dc = 1.243 g/cm3, F(000) = 2656, GOOF = 1.043, m = 0.081 mm-1, the final R = 0.0526 and wR = 0.1267 for 2059 observed reflections with I 〉 2σ(I). 1 and 2 molecules are connected through hydrogen bonds to generate a 2D network and a 1D chain structure, respectively. The preliminary antibacterial activity results showed that the title compounds display excellent antibacterial activities to Escherichia coli, Staphylococcus aureus and Bacillus subtilis.展开更多
4-Bromobenzaldehyde thiosemicarbazone Schiff base (4-BBTS) and its Cu(Ⅱ), Zn(Ⅱ), Co(Ⅱ) and Ni(Ⅱ) complexes were synthesized and characterized by elemental analysis, UV, IR, MS, ^1H NMR, and molar conduct...4-Bromobenzaldehyde thiosemicarbazone Schiff base (4-BBTS) and its Cu(Ⅱ), Zn(Ⅱ), Co(Ⅱ) and Ni(Ⅱ) complexes were synthesized and characterized by elemental analysis, UV, IR, MS, ^1H NMR, and molar conductivity. Using disc diffusion method, the antibacterial activity tests were conducted. The results revealed that the ligand as well as all the complexes exhibits good antibacterial activities against E. Coli. and S. Aureus. Moreover, Cu(Ⅱ) complex shows the best antibacterial activity, which provides beneficial reference for studying the relationship between the structures and performances.展开更多
The compounds have been synthesized and characterized by routine MS, IR and NMR spectrometry methods. The compounds are all active on bacterial strains with the exception of Salmonella typhimirium, with a MIC value of...The compounds have been synthesized and characterized by routine MS, IR and NMR spectrometry methods. The compounds are all active on bacterial strains with the exception of Salmonella typhimirium, with a MIC value of 7.5 mg/mL. They show a percentage of anti-radical activity of 75.476 ± 5.070 for the compound DAN-S and of 68.142 ± 6.539 for the compound DAN-OV. The compounds are sensitive to the two champions used. DAN-S compound is then the most active.展开更多
Zero or negative emissions of carbon dioxide(CO2)is the need of the times,as inexorable rising and alarming levels of CO2 in the atmosphere lead to global warming and severe climate change.The electrochemical CO2 redu...Zero or negative emissions of carbon dioxide(CO2)is the need of the times,as inexorable rising and alarming levels of CO2 in the atmosphere lead to global warming and severe climate change.The electrochemical CO2 reduction(eCO2R)to value‐added fuels and chemicals by using renewable electricity provides a cleaner and more sustainable route with economic benefits,in which the key is to develop clean and economical electrocatalysts.Carbon‐based catalyst materials possess desirable properties such as high offset potential for H2 evolution and chemical stability at the negative applied potential.Although it is still challenging to achieve highly efficient carbon‐based catalysts,considerable efforts have been devoted to overcoming the low selectivity,activity,and stability.Here,we summarize and discuss the recent progress in carbon‐based metal‐free catalysts including carbon nanotubes,carbon nanofibers,carbon nanoribbons,graphene,carbon nitride,and diamonds with an emphasis on their activity,product selectivity,and stability.In addition,the key challenges and future potential approaches for efficient eCO2R to low carbon‐based fuels are highlighted.For a good understanding of the whole history of the development of eCO2R,the CO2 reduction reactions,principles,and techniques including the role of electrolytes,electrochemical cell design and evaluation,product selectivity,and structural composition are also discussed.The metal/metal oxides decorated with carbon‐based electrocatalysts are also summarized.We aim to provide insights for further development of carbon‐based metal‐free electrocatalysts for CO2 reduction from the perspective of both fundamental understanding and technological applications in the future.展开更多
Polyvinyl alcohol (PVA)-sodium polyacrylate (PAAS)-KOH-H2O alkaline polymer electrolyte film with high ionic conductivity was prepared by a solution-casting method. Polymer Ni(OH)2/activated carbon (AC) hybrid...Polyvinyl alcohol (PVA)-sodium polyacrylate (PAAS)-KOH-H2O alkaline polymer electrolyte film with high ionic conductivity was prepared by a solution-casting method. Polymer Ni(OH)2/activated carbon (AC) hybrid supercapacitors with different electrode active material mass ratios (positive to negative) were fabricated using this alkaline polymer electrolyte, nickel hydroxide positive electrodes, and AC negative electrodes. Galvanostatic charge/ discharge and electrochemical impedance spectroscopy (EIS) methods were used to study the electrochemical performance of the capacitors, such as charge/discharge specific capacitance, rate charge/discharge ability, and charge/discharge cyclic stability. Experimental results showed that with the decreasing of active material mass ratio m(Ni(OH)2)/m(AC), the charge/discharge specific capacitance increases, but the rate charge/discharge ability and the charge/discharge cyclic stability decrease.展开更多
Schiff bases are the most widely used organic compounds. They have been shown to exhibit a broad range of biological activities, including antifungal, antibacterial, antimalarial, antiproliferative, anti-inflammatory,...Schiff bases are the most widely used organic compounds. They have been shown to exhibit a broad range of biological activities, including antifungal, antibacterial, antimalarial, antiproliferative, anti-inflammatory, antiviral, and antipyretic properties. This review summarizes the synthesis and biological activities of Schiff bases and their complexes.展开更多
基金National Natural Science Foundation of China,Grant/Award Number:22172063Young Taishan Scholars Program,Grant/Award Number:tsqn201812080+1 种基金China Scholarship Council(CSC),Grant/Award Number:202008130132Independent Cultivation Program of Innovation Team of Ji'nan City,Grant/Award Number:2021GXRC052。
文摘Electrocatalytic water splitting has been identified as a potential candidate for producing clean hydrogen energy with zero carbon emission.However,the sluggish kinetics of oxygen evolution reaction on the anode side of the watersplitting device significantly hinders its practical applications.Generally,the efficiency of oxygen evolution processes depends greatly on the availability of cost‐effective catalysts with high activity and selectivity.In recent years,extensive theoretical and experimental studies have demonstrated that cobalt(Co)‐based nanomaterials,especially low‐dimensional Co‐based nanomaterials with a huge specific surface area and abundant unsaturated active sites,have emerged as versatile electrocatalysts for oxygen evolution reactions,and thus,great progress has been made in the rational design and synthesis of Co‐based nanomaterials for electrocatalytic oxygen evolution reactions.Considering the remarkable progress in this area,in this timely review,we highlight the most recent developments in Co‐based nanomaterials relating to their dimensional control,defect regulation(conductivity),electronic structure regulation,and so forth.Furthermore,a brief conclusion about recent progress achieved in oxygen evolution on Co‐based nanomaterials,as well as an outlook on future research challenges,is given.
文摘In a task-based communicative classroom, group activities are effective ways to devdop students' 4 basic language skills. However, not all group activities can reach the expected results. English teachers should pay attention to some aspects in organizing a classroom group activity.
文摘In English reading, teachers should take students as the main body by creating situations, putting forward tasks,practicing interaction and evaluating teachers and students according to the corresponding classroom goals so as to improve students' English reading skills and the comprehensive use of language ability. Effective reading activities can help improve students' English level at different English reading stages,such as pre-reading stage,w hile-reading stage, post-reading stage.
文摘The genus Populus has long been used for environmental,agroforestry and industrial applications worldwide.Today Populus is also recognized as a desirable crop for biofuel production and a model tree for physiological and ecological research.As such,various modern biotechnologies,including CRISPR/Cas9-based techniques,have been actively applied to Populus for genetic and genomic improvements for traits such as increased growth rate and tailored lignin composition.However,CRISPR/Cas9 has been primarily used as the active Cas9 form to create knockouts in the hybrid poplar clone“717-1B4”(P.tremula x P.alba clone INRA 717-1B4).Alternative CRISPR/Cas9-based technologies,e.g.those involving modified Cas9 for gene activation and base editing,have not been evaluated in most Populus species for their efficacy.Here we employed a deactivated Cas9(dCas9)-based CRISPR activation(CRISPRa)technique to fine-tune the expression of two target genes,TPX2 and LecRLK-G which play important roles in plant growth and defense response,in hybrid poplar clone“717-1B4”and poplar clone“WV94”(P.deltoides“WV94”),respectively.We observed that CRISPRa resulted in 1.2-fold to 7.0-fold increase in target gene expression through transient expression in protoplasts and Agrobacterium-mediated stable transformation,demonstrating the effectiveness of dCas9-based CRISPRa system in Populus.In addition,we applied Cas9 nickase(nCas9)-based cytosine base editor(CBE)to precisely introduce premature stop codons via C-to-T conversion,with an efficiency of 13%–14%,in the target gene PLATZ which encodes a transcription factor involved in plant fungal pathogen response in hybrid poplar clone“717-1B4”.Overall,we showcase the successful application of CRISPR/Cas-based technologies in gene expression regulation and precise gene engineering in two Populus species,facilitating the adoption of emerging genome editing tools in woody species.
文摘<span style="font-family:Verdana;">Three Schiff bases L</span><sub><span style="font-family:Verdana;">1</span></sub><span style="font-family:Verdana;">, L</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> and L</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;"> were synthesized by condensing salicylalde</span><span style="font-family:Verdana;">hyde with 4-aminoantipyrine, ethylendiamine and 2-aminophenol respec</span><span style="font-family:Verdana;">tively and subsequently characterized by various physicochemical investigations. All the three compounds were screened for their </span><i><span style="font-family:Verdana;">In-vitro</span></i><span style="font-family:Verdana;"> antibacterial activity against two gram positive bacteria, </span><i><span style="font-family:Verdana;">Staphylococcus aureus</span></i><span style="font-family:Verdana;"> (S.A), </span><i><span style="font-family:Verdana;">Staphylococcus epidermidis</span></i><span style="font-family:Verdana;"> (S.E) and two gram negative bacteria </span><i><span style="font-family:Verdana;">Klebsiella</span></i><span><span><i><span style="font-family:""> </span></i></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;">pneumoniae</span></i></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;"> (K.P) and </span><i><span style="font-family:Verdana;">Pseudomonas aeruginosa </span></i><span style="font-family:Verdana;">(</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">P.</span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">A) by agar diffusion method. On comparing the results obtained with the activity of commercially available antibiotics such as Ciprofloxacin and Chloramphenicol, the newly synthesized compounds showed comparable antibacterial activities. The solvent methanol exhibit activity against all bacterial species with IZs ranging from 8 ± 0.25 to 17 ± 0.29 mm while the standard antibiotics Ciprofloxacin and Chloramphenicol exhibited an activities with IZs varying from 21.3 ± 0.31 to 28.3 ± 0.32 and 26.3 ± 0.24 mm to 32.3 ± 0.23 mm, respectively. However, the newly synthesized Schiff bases L</span><sub><span style="font-family:Verdana;">1</span></sub><span style="font-family:Verdana;">, L</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> and L</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;"> showed IZs ranging from 7.4 ± 0.23 to 32.5 ± 0.14, 3 ± 0.57 to 12 ± 0.28 and 10 ± 0.20 to 32 ± 0.36 respectively. Among the Schiff bases, L</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;"> showed the activity (32 ± 0.36) against S.E and P.A </span><span style="font-family:Verdana;">which is higher than the activity of standard antibiotics Ciprofloxacin and</span><span style="font-family:Verdana;"> Chloramphenicol against the same bacterial strains. The results obtained revealed that all the synthesized Schiff bases exhibit appreciable antibacterial activity against all the bacteria species which potentially makes them, to apply as wide range antibacterial drugs, after further </span><i><span style="font-family:Verdana;">in-vivo</span></i><span style="font-family:Verdana;"> cytotoxicity investigations. Their activity can also be further modified by changing the functionality of precursors for Schiff base condensation.</span></span></span></span>
文摘Aphasia is a higher brain dysfunction that affects the production or comprehension of speech and the ability to read or write. The purpose of this research is to establish support guidelines based on a questionnaire survey and a language activity analysis of rehabilitation training so that volunteers can more easily assist disabled persons with aphasia. The focus of this study was the non-profit community-based intervention group Yokohama Aphasia Partner Group, which consists of members with aphasia, their families, speech-language-and-hearing therapists, psychiatric social workers, and volunteers. The following results were obtained. (1) Members with aphasia participate in the Partner Group because they can meet others with aphasia on a regular basis as well as participate in the aphasia rehabilitation program with the recovery of language functions. In addition to medical treatment, the community-based support, which improves the environment and other life contextual factors, is important for rehabilitation. (2) An individual with aphasia shows different language actions, and so an individually different support system in accordance with language activity is necessary.
文摘This paper focuses on a beginner adult ESL classroom aiming to enhance their participation under the guidance of“taskbased teaching”method. By incorporating three strategies of priming students to elicit their prior knowledge on certain topic, designing a sequence of tasks to scaffold students for the final produce and modelling with lower level students to ensure their under? standing of task instructions, the activeness could see a significant increase.
文摘Activity based costing (ABC) is a method which can solve many limitations of the traditional cost systems in manufacturing management. In this paper, we investigate how to integrate ABC with workflow technology, and build a workflow meta model supporting ABC. Firstly, the concept and concept model of activity based costing (ABC) are introduced. Next, the meta model of P -PROCE (Process, Product, Resource, Organization, and Cost & Evaluation) is presented. Then the cost meta model is defined by adding ABC to P -PROCE model. Object constraint language (OCL) is used to express meta model and constraints. Finally, we show an enterprise modeling and simulation tool based on the workflow meta model. We can systematically construct an enterprise model and easily and efficiently conduct simulation. Moreover it enables us to analyze and evaluate business processes and its costs.
文摘This study focuses on the effectiveness of the project-based language learning(PBLL) in a college Secretarial Oral English(SOE) Module. Student reflections of the language project work have been analyzed through Activity Theory. Moreover,Data has been collected and categorized based on the components of complex human activity: the subject, object, tools(signs,symbols, and language), the community in which the activity take place, division of labor, and rules. The findings theoretically support the outcome of project-based language learning which align with the object of the activity.
文摘Based on several books on English teaching and learning,this paper gives a general review on task-based teaching.Firstly,it introduces the definitions of task and task-based syllabus and makes two distinctions,namely,"task"and"activity","taskbased teaching"and"communicative teaching".Then it states the notions behind the task-based teaching.Finally,it gives the notes for the application of this approach.
文摘A complex [NIL2] was synthesized, in which L, or to be exact, a Schiff base ligand (HL), was derived from the condensation of 1-phenyl-3-methyl-4-phenylacetyl-5-pyrazolone (PMPAP) with L-phenylalanine methyl ester. They were characterized by IR and single-crystal X-ray diffraction. Green block crystals of both ligand and its complex were grown at room temperature. The ligand, which consists of two individual fragments, crystalizes in the P1 space group (a = 5.6268(5), b = 10.6892(11) and c = 19.4869(18) A). The complex crystalizes in the P21 space group (a -- 21.4076(18), b = 9.4792(8) and c = 25.287(2) A), which consists of a nickel six-coordinated compound. Every fragment is a distorted octahedron with four oxygen and two nitrogen atoms. The Schiff base ligand (HL) and its complex have been tested in vitro to evaluate their antibacterial activity against bacteria Escherichia Coli and Bacillus subtilis. It is found that the complex has higher activity than the corresponding free Schiff base ligand (HL) against the same bacterial.
文摘Base isolated structures have been found to be at risk in near-fault regions as a result of long period pulses that may exist in near-source ground motions. Various control strategies, including passive, active and semi-active control systems, have been investigated to overcome this problem. This study focuses on the development of a semi-active control algorithm based on several performance levels anticipated from an isolated building during different levels of ground shaking corresponding to various earthquake hazard levels. The proposed performance-based algorithm is based on a modified version of the well-known semi-active skyhook control algorithm. The proposed control algorithm changes the control gain depending on the level of shaking imposed on the structure. The proposed control system has been evaluated using a series of analyses performed on a base isolated benchmark building subjected to seven pairs of scaled ground motion records. Simulation results show that the newly proposed algorithm is effective in improving the structural and nonstructural performance of the building for selected earthquakes.
文摘Two new zinc(Ⅱ) complexes, [Zn2L2Ch].2[ZnL(CH3OH)Cl2] 1 and [ZnL2(NO3)2] 2, were synthesized by reacting ZnX2.nH2O (X = Cl^-, NO3^-) and a Schiff base ligand 2-[(4-methylphenylimino)methyl]-6-methoxyphenol (C15HIsNO2, L) which was obtained by the condensation of o-vanillin (2-hydroxy-3-methoxybenzaldehyde) with p-toluidine. Both 1 and 2 were characterized by single-crystal X-ray diffraction technique, elemental analysis, molar conductance, FT-IR, UV-Vis, IH-NMR spectra and thermogravimetrie analysis. The Schiff base ligand and its zinc(Ⅱ) complexes have been tested in vitro to evaluate their antibacterial activity against bacteria, viz., Escherichia Coli, Staphylococcus aureus and Bacillus Subtilis. The results show that these complexes have higher activity than the corresponding free Schiff base ligand against the same bacteria.
基金Supported by the Natural Science Foundation of China(No.21264011,20961007)
文摘Two heterocyclic Schiff bases were synthesized via the condensation reactions of primary amines with carbonyl compounds. 2-[(4-pyridylmethylene)-amino] phenol (compound 1) was synthesized by the interaction of 4-pyridinecarboxaldehyde with o-aminophenol in ethanol solvent; N,N'-bis(3-(furan-2-yl)allylidene)benzene-1,4-diamin (compound 2) was synthesized by the interaction of 3-(2-furyl)acrolein with p-phenylenediamine in ethanol medium. The compounds were characterized by elemental analysis, IR, MS and single-crystal X-ray diffraction. Compound 1 (C12H10N2O) crystallizes in the monoclinic system, space group P21/c with α = 7.0771(7), b = 7.2820(7), c = 19.849(2), b = 96.3390(10)°, V = 1016.66(17) ?3, Z = 4, Mr = 198.22, Dc = 1.295 g/cm3, F(000) = 416, GOOF = 1.060, m = 0.085 mm-1, the final R = 0.0371 and wR = 0.0929 for 1497 observed reflections with I 〉 2σ(I). Compound 2 (C20H16N2O2) crystallizes in the orthorhombic system, space group Fdd2 with α = 26.344(15), b = 48.50(3), c = 5.293(3), V = 6764(7) ?3, Z = 16, Mr = 316.35, Dc = 1.243 g/cm3, F(000) = 2656, GOOF = 1.043, m = 0.081 mm-1, the final R = 0.0526 and wR = 0.1267 for 2059 observed reflections with I 〉 2σ(I). 1 and 2 molecules are connected through hydrogen bonds to generate a 2D network and a 1D chain structure, respectively. The preliminary antibacterial activity results showed that the title compounds display excellent antibacterial activities to Escherichia coli, Staphylococcus aureus and Bacillus subtilis.
基金This work was supported by the Natural Science Foundation of Tianjin (No. 003601711)
文摘4-Bromobenzaldehyde thiosemicarbazone Schiff base (4-BBTS) and its Cu(Ⅱ), Zn(Ⅱ), Co(Ⅱ) and Ni(Ⅱ) complexes were synthesized and characterized by elemental analysis, UV, IR, MS, ^1H NMR, and molar conductivity. Using disc diffusion method, the antibacterial activity tests were conducted. The results revealed that the ligand as well as all the complexes exhibits good antibacterial activities against E. Coli. and S. Aureus. Moreover, Cu(Ⅱ) complex shows the best antibacterial activity, which provides beneficial reference for studying the relationship between the structures and performances.
文摘The compounds have been synthesized and characterized by routine MS, IR and NMR spectrometry methods. The compounds are all active on bacterial strains with the exception of Salmonella typhimirium, with a MIC value of 7.5 mg/mL. They show a percentage of anti-radical activity of 75.476 ± 5.070 for the compound DAN-S and of 68.142 ± 6.539 for the compound DAN-OV. The compounds are sensitive to the two champions used. DAN-S compound is then the most active.
基金The authors thank the financial support from the“Scientific and Technical Innovation Action Plan”Basic Research Field of the Shanghai Science and Technology Committee(19JC1410500)the Fundamental ResearchFunds for the Central Universities(2232018A3‐06)the National Natural Science Foundation of China(91645110).
文摘Zero or negative emissions of carbon dioxide(CO2)is the need of the times,as inexorable rising and alarming levels of CO2 in the atmosphere lead to global warming and severe climate change.The electrochemical CO2 reduction(eCO2R)to value‐added fuels and chemicals by using renewable electricity provides a cleaner and more sustainable route with economic benefits,in which the key is to develop clean and economical electrocatalysts.Carbon‐based catalyst materials possess desirable properties such as high offset potential for H2 evolution and chemical stability at the negative applied potential.Although it is still challenging to achieve highly efficient carbon‐based catalysts,considerable efforts have been devoted to overcoming the low selectivity,activity,and stability.Here,we summarize and discuss the recent progress in carbon‐based metal‐free catalysts including carbon nanotubes,carbon nanofibers,carbon nanoribbons,graphene,carbon nitride,and diamonds with an emphasis on their activity,product selectivity,and stability.In addition,the key challenges and future potential approaches for efficient eCO2R to low carbon‐based fuels are highlighted.For a good understanding of the whole history of the development of eCO2R,the CO2 reduction reactions,principles,and techniques including the role of electrolytes,electrochemical cell design and evaluation,product selectivity,and structural composition are also discussed.The metal/metal oxides decorated with carbon‐based electrocatalysts are also summarized.We aim to provide insights for further development of carbon‐based metal‐free electrocatalysts for CO2 reduction from the perspective of both fundamental understanding and technological applications in the future.
基金Supported by Leading Academic Discipline Project of Shanghai Municipal Education Commission (J50102)
文摘Polyvinyl alcohol (PVA)-sodium polyacrylate (PAAS)-KOH-H2O alkaline polymer electrolyte film with high ionic conductivity was prepared by a solution-casting method. Polymer Ni(OH)2/activated carbon (AC) hybrid supercapacitors with different electrode active material mass ratios (positive to negative) were fabricated using this alkaline polymer electrolyte, nickel hydroxide positive electrodes, and AC negative electrodes. Galvanostatic charge/ discharge and electrochemical impedance spectroscopy (EIS) methods were used to study the electrochemical performance of the capacitors, such as charge/discharge specific capacitance, rate charge/discharge ability, and charge/discharge cyclic stability. Experimental results showed that with the decreasing of active material mass ratio m(Ni(OH)2)/m(AC), the charge/discharge specific capacitance increases, but the rate charge/discharge ability and the charge/discharge cyclic stability decrease.
文摘Schiff bases are the most widely used organic compounds. They have been shown to exhibit a broad range of biological activities, including antifungal, antibacterial, antimalarial, antiproliferative, anti-inflammatory, antiviral, and antipyretic properties. This review summarizes the synthesis and biological activities of Schiff bases and their complexes.