期刊文献+
共找到1,156篇文章
< 1 2 58 >
每页显示 20 50 100
Yolk free egg substitute improves the serum phospholipid profile of mice with metabolic syndrome based on lipidomic analysis
1
作者 Zhihui Yu Lingyu Fan +3 位作者 Fei Tai Lixin Zhang Xiaoyu Zhang Yisheng Chen 《Food Science and Human Wellness》 SCIE CSCD 2024年第1期482-493,共12页
In this study,the impacts of egg consumption on mice model of metabolic syndrome(Met S)were comparatively investigated.Mice were divided into five groups(n=8):normal diet group(ND),high-fat diet group(HFD),HFD with wh... In this study,the impacts of egg consumption on mice model of metabolic syndrome(Met S)were comparatively investigated.Mice were divided into five groups(n=8):normal diet group(ND),high-fat diet group(HFD),HFD with whole egg group(WE),HFD with free-yolk egg substitute group(YFES),and HFD with lovastatin group(Lov).Main biochemical indexes and a non-targeted lipidomic analysis were employed to insight the lipid profile changes in serum.It was revealed that WE could significantly improve serum biochemical indexes by reducing body weight,low-density lipoprotein cholesterol(LDL-C)and total cholesterol(TC),while increasing high-density lipoprotein cholesterol.YFES exhibited remarkably better performance in increasing phosphatidylglycerol and phosphatidic acids,while decreasing phosphatidylinositol than WE.A total of 50 differential lipids biomarkers tightly related to glycerophospholipids metabolism were screened out.Carnitine C18:2 and C12:1,SM(d18:0/12:0),and SM(d18:1/14:1)were significantly upregulated in YFES compared to WE.YFES reduced expression of SREBP-1c and Cpt1a,while did not affect the expression of PPAR-α.Sphingomyelin biomarkers were positively related to the TC(|r|>0.6),while PPAR-αwas negatively correlated with triglyceride and LDL-C levels.To sum up,YFES attenuated HFD-induced Met S by improving the serum phospholipids,which account for its modulation of glycerophospholipid metabolism. 展开更多
关键词 Metabolic syndrome Whole egg Yolk free egg substitute SERUM LIPIDOMICS
下载PDF
A novel approach for 25-gauge transconjunctival sutureless vitrectomy to evaluate vitreous substitutes in rabbits
2
作者 Rui-Jin Ran Ting Wang +2 位作者 Meng-Ying Tao Yue-Qin Gou Ming Zhang 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2023年第10期1568-1573,共6页
AIM:To improve the standard three-port vitrectomy for establishing and evaluating an endotamponade model in rabbits.METHODS:Three ports were prepared near the third eyelid of rabbits,and the infusion port was placed a... AIM:To improve the standard three-port vitrectomy for establishing and evaluating an endotamponade model in rabbits.METHODS:Three ports were prepared near the third eyelid of rabbits,and the infusion port was placed at the inferior nasal quadrant with the inserted cannula linking with a self-designed handheld rigid infusion catheter.All right eyes of rabbits underwent a modified 25-gauge vitrectomy and were subsequently filled with balanced salt solution,silicone oil,and eight-arm polyethylene glycols(8-arm PEGs)hydrogel separately for comparison.Ophthalmic examinations were performed regularly to record the changes after the surgery.RESULTS:Successful vitrectomy was achieved among 44 chinchilla rabbits.The mean operation time was 4.51±1.25min.Four eyes(9.1%)presented limited lens touch and two eyes(4.5%)showed retinal touch during surgery.Incision leakage was found in three eyes(6.8%)after surgery.There was no endophthalmitis,hemorrhage,or retinal detachment during the observation period and ophthalmic examinations after the implantation of vitreous substitutes.CONCLUSION:The modified technique of the standard vitrectomy applied in the endotamponade model in rabbits shows excellent safety and practicality. 展开更多
关键词 surgical technique endotamponade model vitreous substitute three-port vitrectomy RABBIT
下载PDF
Fate of Parent and Substituted Polycyclic Aromatic Hydrocarbons in SBR/MBBR Treatment Process:Experimental Value Against Model Prediction
3
作者 ZHAO Jing TIAN Weijun +3 位作者 LIU Shuhui QIAO Kaili DU Zhaoyang XIE Wenlong 《Journal of Ocean University of China》 SCIE CAS CSCD 2023年第2期479-489,共11页
The knowledge of the existence,distribution and fate of polycyclic aromatic hydrocarbons(PAHs)and substituted polycyclic aromatic hydrocarbons(SPAHs)in wastewater treatment plants(WWTPs)was vital for reducing their co... The knowledge of the existence,distribution and fate of polycyclic aromatic hydrocarbons(PAHs)and substituted polycyclic aromatic hydrocarbons(SPAHs)in wastewater treatment plants(WWTPs)was vital for reducing their concentrations entering the aquatic environment.The concentrations of 13 SPAHs and 16 PAHs were all determined in a WWTP with styrene butadiene rubber(SBR)in partnership with the moving bed biofilm reactor(MBBR)process.SPAHs presented a higher concentration lever than PAHs in nearly all samples.The total removal efficiencies of PAHs and SPAHs ranged from 64.0%to 71.36%and 78.4%to 79.7%,respectively.The total yearly loads of PAHs(43.0 kg)and SPAHs(73.0 kg)were mainly reduced by the primary and SBR/MBBR biological treatment stages.The tertiary treatment stage had a minor contribution to target compounds removal.According to a synthesis and improvement fate model,we found that the dominant processes changed as the chemical octanol water partition coefficient(K_(ow))increased.But the seasonal variations of experimental removal efficiencies were more obvious than that of predicted data.In the primary sedimentation tank,dissolution in the aqueous phase and sorption to sludge/particulate matter were controlling processes for the removal of PAHs and SPAHs.The sorption to sludge and biodegradation were the principal removal mechanisms during the SBR/MBBR biological treatment process.The contribution of volatilization to removal was always insignificant.Furthermore,the basic physicochemical properties and operating parameters influenced the fate of PAHs and SPAHs in the WWTP. 展开更多
关键词 substituted polycyclic aromatic hydrocarbons moving bed biofilm reactor removal efficiency fate process model
下载PDF
Investigation of the Nd-Ce-Mg-Zn/Substituted Hydroxyapatite Effect on Biological Properties and Osteosarcoma Cells
4
作者 Suha Q.AL-Shahrabalee Hussein Alaa Jaber 《Journal of Renewable Materials》 SCIE EI 2023年第3期1485-1498,共14页
Cancerous diseases and diseases resulting from bacteria and fungi are some of the pressures that humans face.Therefore,the development of biomaterials that are resistant to cancerous diseases,bacteria,and fungi has be... Cancerous diseases and diseases resulting from bacteria and fungi are some of the pressures that humans face.Therefore,the development of biomaterials that are resistant to cancerous diseases,bacteria,and fungi has become one of the requirements of the medical field to extend the life of the biomaterial and fight pathogens after implanting these materials inside the human body.One of the important biomaterials used in the field of orthopedics is hydroxyapatite.In this research,Nano substituted hydroxyapatite was prepared by the wet precipitation method,including replacing 5%of the calcium ions with neodymium,cerium,magnesium,and zinc ions in cationic substitution.Many tests were carried out to characterize the prepared material.The biological properties were evaluated by examining the resistance of the substituted hydroxyapatite to bacteria and fungi,in addition to testing the effect of the material on normal cells and bone cancer cells.The results showed a new structure of hydroxyapatite after the substitution process and a significant improvement in the biological properties of the prepared biomaterial compared to other researches. 展开更多
关键词 HYDROXYAPATITE NEODYMIUM CERIUM SUBSTITUTION
下载PDF
An Efficient Approach to 6, 7-Disubstituted-1H-quinoxalin-2-ones
5
作者 Xun LI Qing Ping HU +1 位作者 Xue Gui CUI Dong Hua WANG College of Pharmacy, Shandong University, Jinan 250100 College of Pharmaceuticals and Biotechnology, Tianjin University, Tianjin 300072 《Chinese Chemical Letters》 SCIE CAS CSCD 2004年第12期1400-1402,共3页
A novel approach to the synthesis of 6, 7-disubstituted-1H-quinoxalin-2-ones is described.The title compounds were regioselectively prepared by starting from substituted phenylamines andchloroacetyl chloride through t... A novel approach to the synthesis of 6, 7-disubstituted-1H-quinoxalin-2-ones is described.The title compounds were regioselectively prepared by starting from substituted phenylamines andchloroacetyl chloride through the efficient sequence of acylation, nitration, reduction, intramolecular alkylation, and oxidation. 展开更多
关键词 6 7 -Disubstituted-1H-quinoxalin-2-ones REGIOSELECTIVE substituted phenylamine.
下载PDF
SYNTHESIS OF POLYSUBSTITUTED AROMATIC COMPOUNDS:Ⅰ.THE DIELS-ALDER REACTION OF SELENO SUBSTITUTED 3-SULFOLENES WITH DIMETHYL ACETYLENEDICARBOXYLATE
6
作者 Guang Dian HAN Guo Feng HUANG Institute of Materia Medica,Chinese Academy of Medical Sciences and Peking Union Medical College.Beijing 100050 《Chinese Chemical Letters》 SCIE CAS CSCD 1993年第10期871-872,共2页
The seleno substituted aromatic compounds were prepared via the Diels-Alder reaction of seleno substituted 3-sulfolenes with dimethyl acetylenedicarboxylate followed by DDQ dehydrogenation.
关键词 TMS HNMR SYNTHESIS OF POLYsubstituteD AROMATIC COMPOUNDS THE DIELS-ALDER REACTION OF SELENO substituteD 3-SULFOLENES WITH DIMETHYL ACETYLENEDICARBOXYLATE OCH PPM
下载PDF
N-Substituted benzoxazolyl ureas and thioureas in Biginelli reaction promoted by trifluoromethane sulfonic acid:An efficient and convenient synthesis of substituted benzoxazolyl 3,4-dihydropyrimidine(1H)-(thio)-ones
7
作者 M.Saranga Pani M.Arjun +2 位作者 D.Sridhar K.Srinivas T.Raviprasad 《Chinese Chemical Letters》 SCIE CAS CSCD 2009年第8期909-912,共4页
An efficient synthesis of 3,4-dihydropyrimidine 2 (1H)-ones and thiones (3,4-DHPMs) core was prepared by one-pot threecomponent Biginelli condensation and which was catalyzed by trifluoromethane sulfonic acid. The... An efficient synthesis of 3,4-dihydropyrimidine 2 (1H)-ones and thiones (3,4-DHPMs) core was prepared by one-pot threecomponent Biginelli condensation and which was catalyzed by trifluoromethane sulfonic acid. The classical BigneUi reaction has been extended by the use of N-substituted benzoxazolyl semicarbazides and thiosemicarbazides and this method has the advantage of excellent yields and short reaction times. ?2009 M. Saranga Pard. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved. 展开更多
关键词 Trifluoromcthane sulfonic acid N-substituted scmicarbazidcs and thioscmicarbazidcs β-Ketocster substituted benzoxazolyl 3 4-dihydropyrimidinc (IH)-(thio)-ones
下载PDF
Vitreous substitutes: challenges and directions 被引量:20
8
作者 Qian-Ying Gao Yue Fu Yan-Nian Hui 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2015年第3期437-440,共4页
The natural vitreous body has a fine structure and complex functions. The imitation of the natural vitreous body by vitreous substitutes is a challenging work for both researchers and ophthalmologists. Gases, silicone... The natural vitreous body has a fine structure and complex functions. The imitation of the natural vitreous body by vitreous substitutes is a challenging work for both researchers and ophthalmologists. Gases, silicone oil, heavy silicone oil and hydrogels, particularly the former two vitreous substitutes are clinically widely used with certain complications. Those, however, are not real artificial vitreous due to lack of structure and function like the natural vitreous body. This article reviews the situations, challenges, and future directions in the development of vitreous substitutes, particularly the experimental and clinical use of a new artificial foldable capsular vitreous body. 展开更多
关键词 vitreous substitute artificial vitreous foldable capsular vitreous body silicone oil
下载PDF
Overall assessment of antibiotic substitutes for pigs:a set of meta-analyses 被引量:10
9
作者 Bocheng Xu Jie Fu +3 位作者 Luoyi Zhu Zhi Li Mingliang Jin Yizhen Wang 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2021年第2期763-777,共15页
Background:Antibiotic growth promoters are widely used to improve weight gain.However,the abuse of antibiotics can have many negative effects on people.Developing alternatives to antibiotics is an urgent need in lives... Background:Antibiotic growth promoters are widely used to improve weight gain.However,the abuse of antibiotics can have many negative effects on people.Developing alternatives to antibiotics is an urgent need in livestock production.We aimed to perform a meta-analysis and network meta-analysis(NMA)to investigate the effects of feed additives as potential antibiotic substitutes(ASs)on bacteriostasis,growth performance,intestinal morphology and immunity.Furthermore,the primary,secondary,and tertiary ASs were defined by comparing their results with the results of antibiotics.Results:Among 16,309 identified studies,37 were summarized to study the bacteriostasis effects of feed additives,and 89 were included in the meta-analysis and NMA(10,228 pigs).We summarized 268 associations of 57 interventions with 32 bacteria.The order of bacteriostasis effects was as follows:antimicrobial peptides(AMPs)≈antibiotics>organic acids>plant extracts>oligosaccharides.We detected associations of 11 feed additives and 11 outcomes.Compared with a basal diet,plant extract,AMPs,probiotics,microelements,organic acids,bacteriophages,lysozyme,zymin,and oligosaccharides significantly improved growth performance(P<0.05);organic acids,probiotics,microelements,lysozyme,and AMPs remarkably increased the villus height:crypt depth ratio(V/C)(P<0.05);and plant extracts,zymin,microelements,probiotics,and organic acids notably improved immunity(P<0.05).The optimal AMP,bacteriophage,lysozyme,microelements,oligosaccharides,organic acids,plants,plant extracts,probiotics,and zymin doses were 0.100%,0.150%,0.012%,0.010%,0.050%,0.750%,0.20%,0.040%,0.180%,and 0.100%,respectively.Compared with antibiotics,all investigated feed additives exhibited no significant difference in effects on growth performance,IgG,and diarrhoea index/rate(P>0.05);AMPs and microelements significantly increased V/C(P<0.05);and zymin significantly improved lymphocyte levels(P<0.05).Furthermore,linear weighting sum models were used to comprehensively estimate the overall impact of each feed additive on pig growth and health.Conclusions:Our findings suggest that AMPs and plant extracts can be used as primary ASs for weaned piglets and growing pigs,respectively.Bacteriophages,zymin,plants,probiotics,oligosaccharides,lysozyme,and microelements can be regarded as secondary ASs.Nucleotides and organic acids can be considered as tertiary ASs.Future studies should further assess the alternative effects of combinational feed additives. 展开更多
关键词 Antibiotic substitutes Dose-effect relationship Feed additives META-ANALYSIS Network meta-analysis PIGS
下载PDF
Structural Characterization and Acute Toxicity Prediction of Substituted Aromatic Compounds by Using Molecular Vertexes Correlative Index 被引量:6
10
作者 李建凤 廖立敏 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2013年第4期557-563,共7页
A molecular structural characterization (MSC) method called molecular vertexes correlative index (MVCI) was used to describe the structures of 30 substituted aromatic compounds. Through multiple linear regression ... A molecular structural characterization (MSC) method called molecular vertexes correlative index (MVCI) was used to describe the structures of 30 substituted aromatic compounds. Through multiple linear regression (MLR) and stepwise multiple regression (SMR), a quantitative structure-toxicity relationship (QSTR) model with 4 variables was obtained. The correlation coefficient (R) of the model was 0.9467. Through partial least-squares regression (PLS), another QSTR model with 5 principal components was obtained. The correlation coefficient (R) of the model was 0.9518. Both models were evaluated by performing the cross-validation with the leave-one-out (LOO) procedure and the Cross-Validation (CV) correlation coefficients (Rcv) were 0.9208 and 0.9214, respectively. The results suggested good stability and predictability of the models, and the molecular vertexes correlative index could successfully describe the structures of the substituted aromatic compounds. 展开更多
关键词 substituted aromatics acute toxicity structural descriptors QSAR
下载PDF
Ability of bone graft substitutes to support the osteoprogenitor cells: An in-vitro study 被引量:3
11
作者 Ziad Dahabreh Michalis Panteli +3 位作者 Ippokratis Pountos Mark Howard Peter Campbell Peter V Giannoudis 《World Journal of Stem Cells》 SCIE CAS 2014年第4期497-504,共8页
AIM: To compare seven commercially available bone graft substitutes(BGS) in terms of these properties and without using any additional biological growth factors.METHODS: Porcine osteoprogenitor cells were loaded on se... AIM: To compare seven commercially available bone graft substitutes(BGS) in terms of these properties and without using any additional biological growth factors.METHODS: Porcine osteoprogenitor cells were loaded on seven commercially available BGS and allowed to proliferate for one week followed by osteogenic induction. Staining for live/dead cells as well as scanning electron microscopy(SEM) was carried out to determine viability and cellular binding. Further outcome measures included alkaline phosphatase(ALP) assays with normalisation for DNA content to quantify osteogenic potential. Negative and positive control experiments were carried out in parallel to validate the results.RESULTS: Live/dead and SEM imaging showed higher viability and attachment with β-tricalcium phosphate(β-TCP) than with other BGS(P < 0.05). The average ALP activity in nmol/mL(normalised value for DNA content in nmol/μg DNA) per sample was 657.58(132.03) for β-TCP, 36.22(unable to normalise) for calcium sulphate, 19.93(11.39) for the Hydroxyapatite/Tricalcium Phosphate composite, 14.79(18.53) for polygraft, 13.98(8.15) for the highly porous β-Tricalcium Phosphate, 5.56(10.0) for polymers, and 3.82(3.8) for Hydroxyapatite.CONCLUSION: Under the above experimental conditions, β-TCP was able to maintain better the viability of osteoprogenitor cells and allow proliferation and differentiation(P < 0.05). 展开更多
关键词 BONE GRAFT BONE GRAFT substitute OSTEOPROGENITOR cells Fracture HEALING BONE
下载PDF
Synthesis,Characterization and Antibacterial Property of Strontium Half and Totally Substituted Hydroxyapatite Nanoparticles 被引量:4
12
作者 LIN Yingguang YANG Zhuoru +1 位作者 CHENG Jiang WANG Lianshi 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2008年第4期475-479,共5页
Nanoparticles of hydroxyapatite(HAP), strontium half substituted hydroxyapatite (SrCaHAP) and strontium totally substituted hydroxyapatite (SrHAP) were prepared by sol-gel-supercritical fluid drying (SCFD) met... Nanoparticles of hydroxyapatite(HAP), strontium half substituted hydroxyapatite (SrCaHAP) and strontium totally substituted hydroxyapatite (SrHAP) were prepared by sol-gel-supercritical fluid drying (SCFD) method. The nanoparticles were characterized by element content analysis, FT-IR, XRD and TEM, and the effects of strontium substitution on crystal structure, crystallinity, particle shape and antibacterial properties of the nanoparticles on Escherichia coli, Staphylococcus aureus, Lactobacillus were researched. Results show that strontium can half and totally substitute for calcium and enter the structure of apatite according to the initial atomic ratios of Sr/[Sr+Ca] as 0.5, 1. The substitution decreases the IR wavenumbers of SrCaHAP and SrHAP, and changes the morphology of the nanoparticles from short rod shaped HAP to needle shaped SrCaHAP, and back to short rod shaped SrHAP. The crystallinity of HAP is higher than that of SrCaHAP, but is lower than that of SrHAP. Moreover, the antibacterial property of SrCaHAP and SrHAP are improved after the calcium is half and totally substituted by strontium. 展开更多
关键词 sol-gel-supercritical fluid drying NANOPARTICLES strontium substituted hydroxyapatite antibacterial property
下载PDF
Bone graft substitutes for spine fusion: A brief review 被引量:4
13
作者 Ashim Gupta Nitin Kukkar +3 位作者 Kevin Sharif Benjamin J Main Christine E Albers Saadiq F El-Amin Ⅲ 《World Journal of Orthopedics》 2015年第6期449-456,共8页
Bone graft substitutes are widely used in the field of orthopedics and are extensively used to promote vertebral fusion. Fusion is the most common technique in spine surgery and is used to treat morbidities and reliev... Bone graft substitutes are widely used in the field of orthopedics and are extensively used to promote vertebral fusion. Fusion is the most common technique in spine surgery and is used to treat morbidities and relieve discomfort. Allograft and autograft bone substitutes are currently the most commonly used bone grafts to promote fusion. These approaches pose limitations and present complications to the patient. Numerous alternative bone graft substitutes are on the market or have been developed and proposed for application. These options have attempted to promote spine fusion by enhancing osteogenic properties. In this review, we reviewed biology of spine fusion and the current advances in biomedical materials and biological strategies for application in surgical spine fusion. Our findings illustrate that, while many bone graft substitutes perform well as bone graft extenders, only osteoinductive proteins(recombinant bone morphogenetic proteins-2 and osteogenic protein-1) provide evidence for use as both bone enhancers and bone substitutes for specific types of spinal fusion. Tissue engineered hydrogels, synthetic polymer composites and viral based gene therapy also holds the potential to be used for spine fusion in future, though warrants further investigation to be used in clinical practice. 展开更多
关键词 BONE ENHANCERS BONE graft substituteS SPINE fusion AUTOGRAFT ALLOGRAFT
下载PDF
Construction of a full-thickness human corneal substitute from anterior acellular porcine corneal matrix and human corneal cells 被引量:2
14
作者 Kai Zhang Xiao-Xiao Ren +2 位作者 Ping Li Kun-Peng Pang Hong Wang 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2019年第3期351-362,共12页
AIM: To construct functional human full-thickness corneal replacements.METHODS: Acellular porcine corneal matrix(APCM) was developed from porcine cornea by decellulariztion. The biomechanical properties of anterior-AP... AIM: To construct functional human full-thickness corneal replacements.METHODS: Acellular porcine corneal matrix(APCM) was developed from porcine cornea by decellulariztion. The biomechanical properties of anterior-APCM(AAPCM) and posterior-APCM(PAPCM) were checked using uniaxial tensile testing. Human corneal cells were obtained by cell culture. Suspending ring was designed by deformation of an acupuncture needle. MTT cytotoxicity assay was used to check the cytotoxicity of suspending ring soaking solutions. A new three-dimensional organ culture system was established by combination of suspending ring, 48-well plate and medium together. A human full-thickness corneal substitute was constructed from human corneal cells with AAPCM in an organ coculture system. Biochemical marker expression of the construct was measured by immunofluorescent staining and morphological structures were observed using scanning electron microscopy. Pump function and biophysical properties were examined by penetrating keratoplasty and follow-up clinical observations.RESULTS: There were no cells in the AAPCM or PAPCM, whereas collagen fibers, Bowman's membrane, and Descemet's membrane were retained. The biomechanical property of AAPCM was better than PAPCM. Human corneal cells grew better on the AAPCM than on the PAPCM.There was no cytotoxicity for the suspending ring soaking solutions. For the constructed full-depth human corneal replacements keratocytes scattered uniformly throughout the AAPCM and expressed vimentin. The epithelial layer was located on the surface of Bowman's membrane and composed of three or four layers of epithelial cells expressing cytokeratin 3. One layer of endothelial cells covered the stromal surface of AAPCM, expressed Na+/K+ATPase and formed the endothelial layer. The construct was similar to normal human corneas, with many microvilli on the epithelial cell surface, stromal cells with a long shuttle shape, and zonula occludens on the interface of endothelial cells. The construct withstood surgical procedures during penetrating keratoplasty. The corneal transparency increased gradually and was almost completely restored 7 d after surgery.CONCLUSION: AAPCM is an ideal scaffold for constructing full-thickness corneal replacement, and functional human full-thickness corneal replacements are successfully constructed using AAPCM and human corneal cells. 展开更多
关键词 full-thickness human CORNEAL substitute anterior-acellular PORCINE CORNEAL MATRIX posterior-acellular PORCINE CORNEAL MATRIX human CORNEAL cells
下载PDF
A Novel Green Preparation ofα,α′-Bis(substituted benzylidene)-cycloalkanones Promoted by FeCl3·6H2O in Ionic Liquid 被引量:5
15
作者 Xin Ying ZHANG, Xue Sen FAN, Hong Ying NIU, Jian Ji WANGSchool of Chemical and Environmental Sciences, Henan Normal University, Key Laboratory ofEnvironmental Science and Engineering of Henan Education Department,Xinxiang 453002 《Chinese Chemical Letters》 SCIE CAS CSCD 2003年第10期1005-1007,共3页
a, a'-Bis(substituted benzylidene)cycloalkanones were efficiently prepared from cycloalkanones and benzaldehydes in [bmim][BF4] by using iron(III) chloride hexahydrate as a catalyst. It is shown that [bmim][BF4] a... a, a'-Bis(substituted benzylidene)cycloalkanones were efficiently prepared from cycloalkanones and benzaldehydes in [bmim][BF4] by using iron(III) chloride hexahydrate as a catalyst. It is shown that [bmim][BF4] and iron(III) chloride hexahydrate can be quantitatively recovered and be reused effectively for many times. Compared with the known methods, this novel process has the advantage of being an envkonmentally benign process together with good yields and mild reaction conditions. 展开更多
关键词 Ionic liquid a a'-bis(substituted benzylidene)cycloalkanones iron(III) chloride hexahydrate.
下载PDF
Determination and QSAR Study on the Toxicity of Substituted Phenol against Qinghaiensis sp (Q67) 被引量:6
16
作者 尤小军 刘辉 +1 位作者 杨郭英 王遵尧 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2009年第10期1311-1316,共6页
Toxicities (-1gEC50) of 16 phenolic compounds against Q67 were determined, and structural parameters as well as thermodynamic parameters of these compounds were obtained through fully optimized calculations by using... Toxicities (-1gEC50) of 16 phenolic compounds against Q67 were determined, and structural parameters as well as thermodynamic parameters of these compounds were obtained through fully optimized calculations by using B3LYP method of density functional theory (DFT) at the 6-311G^** level. Moreover, a 3-parameter (molecular average polarizability (α), heat energy corrected value (Eth) and the most positive hydrogen atomic charge (qH^+)) correlation model with R^2 = 0.981 and q^2 = 0.967 to predict -1gEC50 was obtained from experimental data based on the above-mentioned parameters as theoretical descriptors. Therein a was the most significant on -1gEC50. Variance Inflation Factors (VIF), t-value and cross-validation were applied to verify the model, confirming that the resultant model has fairly better stability and predictive ability to predict -1gEC50 of similar compounds. 展开更多
关键词 qinghaiensis sp (Q67) toxicity (-1gEC50) quantitative structure-activity relationship (QSAR) density functional theory (DFT) environmental pollutant substituted phenol
下载PDF
Oxygen permeation and phase structure properties of partially A-site substituted BaCo_(0.7)Fe_(0.225)Ta_(0.075)O_(3-δ) perovskites 被引量:2
17
作者 Bo Jiang Hongwei Cheng +3 位作者 Longfei Luo Xionggang Lu Naijun Zhang Jizhong Liu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2014年第2期164-170,共7页
Ba0.9R0.1Co0.TFe0.225Ta0.07503-δ (BRCFT, R = Ca, La or Sr) membranes were synthesized by a solid-state reaction. Metal cation Ca2+, La3+ or Sr2+ doping on A-site partially substituted Ba2+ in BaCoo.TFe0.225Ta0.... Ba0.9R0.1Co0.TFe0.225Ta0.07503-δ (BRCFT, R = Ca, La or Sr) membranes were synthesized by a solid-state reaction. Metal cation Ca2+, La3+ or Sr2+ doping on A-site partially substituted Ba2+ in BaCoo.TFe0.225Ta0.07503-δ oxides, and its subsequent effects on phase structure stability, oxygen permeability and oxygen desorption were systematically investigated by XRD, TG-DSC, Hz-TPR, O2-TPD techniques and oxygen permeation experiments. The partial substitution with Ca2+, La3+ or Sr2+, whose ionic radii are smaller than that of Ba2+, succeeded in stabilizing the cubic perovskite structure without formation of impurity phases, as revealed by XRD analysis. Oxygen-involving experi- ments showed that BRCFT with A-site fully occupied by Ba2+ exhibited good oxygen permeation flux under He flow, reaching about 2.3 mL.min-l .cm-2 at 900 with I mm thickness. Of all the membranes, BLCFT membrane showed better chemical stability in CO2, owing to the reduction in alkalinity of the mixed conductor oxide by La doping. In addition, we also found the stability of the perovskite structure under reducing atmospheres was strengthened by increasing the size of A-site cation (Ba2+〉La3+〉SrZ+〉Ca2+). 展开更多
关键词 PEROVSKITE phase stability oxygen permeation A-site substituted
下载PDF
Experimental and QSPR Studies on n-Octanol/water Partition Coefficient (lgK_(ow)) of Substituted Aniline 被引量:4
18
作者 戴勇 江建林 +1 位作者 王遵尧 薛群 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2007年第12期1449-1454,共6页
The n-octanol/water partition coefficients (lgKow) of 18 substituted anilines were determined at 25 ℃ by shake-flask method. The geometrical optimization of substituted anilines has been performed at B3LYP/6-311G^... The n-octanol/water partition coefficients (lgKow) of 18 substituted anilines were determined at 25 ℃ by shake-flask method. The geometrical optimization of substituted anilines has been performed at B3LYP/6-311G^** level with Gaussian98 program, and the molecular surface areas of substituted anilines were calculated using ChemOffice 2004 program. The calculated structural parameters of substituted anilines were used as theoretical descriptors and the two-parameter (molecular surface area (MA) and the energy of the highest occupied molecular orbital (EaoMo)) quantitative structure-property relationship (QSPR) model of lgKow for substituted aniline with molecular structural parameters was developed by multi-linear regression method. The regression coefficient square (r^2) is 0.990 and the standard deviation SE 0.109. The model was validated by variance inflation factors (VIF) and t-test, and the results show that there exists small self-correlation between variables of the model with perfect stability. The model gives results in good qualitative agreement with experimental data. At last, the model was applied to predict lgKow values of five substituted anilines whose lgKow values have not been determined experimentally. 展开更多
关键词 substituted aniline n-octanol/water partition coefficient shake-flask method DFT quantitative structure-property relationship (QSPR)
下载PDF
Creep-Recovery and Relaxation Behavior of High Density Polyethylene/Hydroxyapatite Nano Particles for Bone Substitutes: Effects of Gamma Radiation 被引量:2
19
作者 H. Fouad Othman Y. Alothman 《Journal of Biosciences and Medicines》 2014年第2期64-66,共3页
The following article has been retracted due to the fact that it cannot be accepted by the author as a journal publication. The Editorial Board takes a very strong respect to the author’s situation on this matter. Th... The following article has been retracted due to the fact that it cannot be accepted by the author as a journal publication. The Editorial Board takes a very strong respect to the author’s situation on this matter. This paper published in Journal of Biosciences and Medicines Vol.2 No.2, April 2014, has been removed from this site. 展开更多
关键词 Nano Particle HYDROXYAPATITE CREEP RECOVERY RELAXATION Bone substitute Radiation
下载PDF
Strategic Thinking on Developing Petroleum Substitutes in China 被引量:1
20
作者 Yin Jianping Liu Danfeng 《Petroleum Science》 SCIE CAS CSCD 2006年第4期46-51,共6页
The continual growth of Chinese economy indicates that the oil demand in China will maintain a strongly rising tendency in the future. With increasing oil consumption, the contradiction between supply and demand will ... The continual growth of Chinese economy indicates that the oil demand in China will maintain a strongly rising tendency in the future. With increasing oil consumption, the contradiction between supply and demand will become more and more serious, which can be resolved by developing petroleum substitutes. This paper analyzes different influence factors, displays the development trend and probes into the strategy in developing petroleum substitutes in China. 展开更多
关键词 China petroleum substitute development trend development strategy
下载PDF
上一页 1 2 58 下一页 到第
使用帮助 返回顶部