期刊文献+
共找到40,956篇文章
< 1 2 250 >
每页显示 20 50 100
Buxu Tongyu Granule Alleviates Myocardial Ischemia by Activating Vascular Smooth Muscle Cell Soluble Guanylate Cyclase to Inhibit Abnormal Vasomotion
1
作者 Shuang Yang Yixiu Zhao +12 位作者 Xiaoling Cheng Tingting Zhan Jiaying Tian Xue Liu Chunyue Ma Zhiqi Wang Luying Jin Qian Liu Yanli Wang Jian Huang Jinhui Wang Yan Zhang Baofeng Yang 《Engineering》 SCIE EI CAS CSCD 2024年第7期133-143,共11页
Myocardial ischemia is a serious threat to human health,and vascular dysfunction is its main cause.Buxu Tongyu(BXTY)Granule is an effective traditional Chinese medicine(TCM)for treating myocardial ischemia.However,the... Myocardial ischemia is a serious threat to human health,and vascular dysfunction is its main cause.Buxu Tongyu(BXTY)Granule is an effective traditional Chinese medicine(TCM)for treating myocardial ischemia.However,the underlying mechanism of BXTY is still unclear.In this study,we demonstrate that BXTY ameliorates myocardial ischemia by activating the soluble guanylate cyclase(sGC)-30,50-cyclic guanosine monophosphate(cGMP)-protein kinase G(PKG)signaling pathway in vascular smooth muscle cells(VSMCs)to dilate the arteries.BXTY was given by gavage for ten consecutive days before establishing an animal model of acute myocardial ischemia in mice via the intraperitoneal injection of pituitrin.The results showed that BXTY alleviated the symptoms of myocardial ischemia induced by pituitrin in mice,including electrocardiogram abnormalities and changes in plasma enzymes.In addition,BXTY dilated pre-constricted blood vessels and inhibited the vasoconstriction of the superior mesenteric artery in a dose-dependent but endothelial-independent manner.These effects were eliminated by preincubating vascular rings with the sGC inhibitors NS 2028 or ODQ,or with the PKG inhibitor KT 5823.Moreover,BXTY increased the protein expression of sGC-b1 and the intracellular second messenger cGMP level in mouse aortic vascular smooth muscle cells(MOVAs).NS 2028 or ODQ reversed these effects of BXTY.The expression level of the cGMP downstream effector protein PKG-1 increased after treating MOVAs with BXTY.NS 2028,ODQ,or KT 5823 also reversed this effect of BXTY.In conclusion,BXTY can improve the symptoms of acute myocardial ischemia in mice,and activating the sGC-cGMP-PKG pathway in VSMCs to induce vasodilation is its key pharmacodynamic mechanism. 展开更多
关键词 Myocardial ischemia VASOMOTION soluble guanylate cyclase Buxu Tongyu Granule
下载PDF
Soluble ST2:A Novel Biomarker for Diagnosis and Prognosis of Cardiovascular Disease
2
作者 Yin FENG Li-qun HE 《Current Medical Science》 SCIE CAS 2024年第4期669-679,共11页
The increasing incidence of cardiovascular disease(CVD)is a significant global health concern,affecting millions of individuals each year.Accurate diagnosis of acute CVD poses a formidable challenge,as misdiagnosis ca... The increasing incidence of cardiovascular disease(CVD)is a significant global health concern,affecting millions of individuals each year.Accurate diagnosis of acute CVD poses a formidable challenge,as misdiagnosis can significantly decrease patient survival rates.Traditional biomarkers have played a vital role in the diagnosis and prognosis of CVDs,but they can be influenced by various factors,such as age,sex,and renal function.Soluble ST2(sST2)is a novel biomarker that is closely associated with different CVDs.Its low reference change value makes it suitable for continuous measurement,unaffected by age,kidney function,and other confounding factors,facilitating risk stratification of CVDs.Furthermore,the combination of sST2 with other biomarkers can enhance diagnostic accuracy and prognostic value.This review aims to provide a comprehensive overview of sST2,focusing on its diagnostic and prognostic value as a myocardial marker for different types of CVDs and discussing the current limitations of sST2. 展开更多
关键词 soluble ST2 cardiovascular disease combined biomarker diagnosis and prognosis LIMITATIONS
下载PDF
Experimental verification of nanonization enhanced solubility for poorly soluble optoelectronic molecules
3
作者 Jingzhou Guo Yuanzuo Zou +4 位作者 Bo Shi Yuan Pu Jiexin Wang Dan Wang Jianfeng Chen 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第8期8-15,共8页
Solubility enhancement has been a priority to overcome poor solubility with optoelectronic molecules for solution-processable devices. This study aims to obtain experimental data on the effect of particle sizes on the... Solubility enhancement has been a priority to overcome poor solubility with optoelectronic molecules for solution-processable devices. This study aims to obtain experimental data on the effect of particle sizes on the solubility properties of several typical optoelectronic molecules in organic solvents, including the solubility results of 1,3-bis(9-carbazolyl)benzene(m CP), 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)ben zene(TPBi) and 2-(4-tert-butylphenyl)-5-(4-biphenyl)-1,3,4-oxadiazole(PBD) in ethanol and acetonitrile,respectively. Nanoparticles of m CP, TPBi and PBD with sizes from dozens to several hundred nanometers were prepared by solvent antisolvent precipitation method and their solubility were determined by using isothermal saturation method. The saturation solubility of nanoparticles of three kinds of optoelectronic molecules exhibited increase of 12.9%-25.7% in comparison to the same raw materials in the form of microparticles. The experimental evidence indicates that nanonization technology is a feasible way to make optoelectronic molecules dissolve in liquids with enhanced solubility. 展开更多
关键词 Nanonization Solubility enhancement Optoelectronic molecules Solution processing
下载PDF
Quantification of soluble epoxide hydrolase inhibitors in experimental and clinical samples using the nanobody-based ELISA
4
作者 Huiyi Yang Meng Qi +6 位作者 Qiyi He Sung Hee Hwang Jun Yang Mark McCoy Christophe Morisseau Suqing Zhao Bruce D.Hammock 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2023年第9期1013-1023,共11页
To ensure proper dosage of a drug,analytical quantification of it in biofluid is necessary.Liquid chromatography mass spectrometry(LC-MS)is the conventional method of choice as it permits accurate identification and q... To ensure proper dosage of a drug,analytical quantification of it in biofluid is necessary.Liquid chromatography mass spectrometry(LC-MS)is the conventional method of choice as it permits accurate identification and quantification.However,it requires expensive instrumentation and is not appropriate for bedside use.Using soluble epoxide hydrolase(sEH)inhibitors(EC5026 and TPPU)as examples,we report development of a nanobody-based enzyme-linked immunosorbent assay(ELISA)for such small molecules and its use to accurately quantify the drug chemicals in human samples.Under optimized conditions,two nanobody-based ELISAs were successfully established for EC5026 and TPPU with low limits of detection of 0.085 ng/mL and 0.31 ng/mL,respectively,and two order of magnitude linear ranges with high precision and accuracy.The assay was designed to detect parent and two biologically active metabolites in the investigation of a new drug candidate EC5026.In addition,the ELISAs displayed excellent correlation with LC-MS analysis and evaluation of inhibitory potency.The results indicate that nanobody-based ELISA methods can efficiently analyze drug like compounds.These methods could be easily implemented by the bedside,in the field in remote areas or in veterinary practice.This work illustrates that nanobody based assays offer alternative and supplementary analytical tools to mass spectrometry for monitoring small molecule medicines during clinical development and therapy.Attributes of nanobody based pharmaceutical assays are discussed. 展开更多
关键词 NANOBODY IMMUNOASSAY soluble epoxide hydrolase inhibitors METABOLITES Small molecules
下载PDF
Eukaryotic expression, purification and activity characterization of human soluble DSG2 extracellular domain protein
5
作者 CHEN Nan LI Xiao-yue +6 位作者 GU Xin-yu WU Tong-xin ZHANG Ru LI Yun TANG Xiang-ping DAI Jin YI Yong-xiang 《Journal of Hainan Medical University》 CAS 2023年第10期1-7,共7页
Objective:To construct a secretory eukaryotic expression vector of DSG2 fused with the Fc region of the human IgG,to validate its expression in 293T cells,and to purify the secretory protein with biological activity.M... Objective:To construct a secretory eukaryotic expression vector of DSG2 fused with the Fc region of the human IgG,to validate its expression in 293T cells,and to purify the secretory protein with biological activity.Methods:The DSG2 extracellular domain fragment gene(DSG2ex),was amplified by PCR,and was inserted into the eukaryotic expression plasmid pCMV3-IgG1 to construct the recombinant eukaryotic expression plasmid-pCMV3-DSG2ex-IgG1.The successfully constructed eukaryotic expression plasmid was transfected into 293T cells to express and secrete DSG2 extracellular domain protein.The targeted protein was purified from the cell culture supernatant by Protein A affinity chromatography and confirmed by Western Blotting and ELISA.Results:The pCMV3-DSG2ex-IgG1 eukaryotic expression plasmid was successfully constructed.The highest protein expression level was obtained with 293T cells after 96 h of transfection.The relative molecular mass of the purified product was between 100 and 130 kDa was estimated by SDS-PAGE,which was consistent with the expectation.The yield of the purified protein reached 0.8 mg/ml with a purity over 90%.The purified DSG2 extracellular domain protein with IgG1 tag was recognized by IgG monoclonal antibodies by Western blotting.Moreover,the ELISA results showed that the prepared DSG2 extracellular domain protein had significant binding activity to human type 55 adenovirus Fiber Knob protein(HAdV-55).Conclusion:A simple and efficient method for eukaryotic expression and purification of human soluble DSG2 extracellular domain protein was successfully established,and biologically active DSG2 extracellular domain protein was purified,which laid the foundation for the later study of its protein function and anti-adenovirus drugs. 展开更多
关键词 Human soluble DSG2 extracellular domain protein Eukaryotic expression PURIFICATION Activity characterization
下载PDF
Elevated soluble fas blood concentrations in patients dying from spontaneous intracerebral hemorrhage
6
作者 Leonardo Lorente María M Martín +5 位作者 Antonia Pérez-Cejas Luis Ramos-Gómez Jordi Solé-Violan Juan J Cáceres Alejandro Jiménez Agustín F González-Rivero 《World Journal of Critical Care Medicine》 2023年第2期63-70,共8页
BACKGROUND Several studies of spontaneous intracerebral hemorrhage(SICH)patients have shown apoptotic changes in brain samples after hematoma evacuation.However,there have been no data on the association between blood... BACKGROUND Several studies of spontaneous intracerebral hemorrhage(SICH)patients have shown apoptotic changes in brain samples after hematoma evacuation.However,there have been no data on the association between blood concentrations of soluble fas(sFas)(the main surface death receptor of the extrinsic apoptosis pathway)and the prognosis of spontaneous intracranial hypotension(SIH)patients.AIM To determine whether there is an association between blood sFas concentrations and SICH patient mortality.METHODS We included patients with severe and supratentorial SIH.Severe was defined as having Glasgow Coma Scale<9.We determined serum sFas concentrations at the time of severe SICH diagnosis.RESULTS We found that non-surviving patients(n=36)compared to surviving patients(n=39)had higher ICH score(P=0.001),higher midline shift(P=0.004),higher serum sFas concentrations(P<0.001),and lower rate of early hematoma evacuation(P=0.04).Multiple logistic regression analysis showed an association between serum sFas concentrations and 30-d mortality(odds ratio=1.070;95%confidence interval=1.014-1.129;P=0.01)controlling for ICH score,midline shift,and early hematoma evacuation.CONCLUSION The association of blood sFas concentrations and SICH patient mortality is a novel finding in our study. 展开更多
关键词 Spontaneous intracerebral hemorrhage soluble fas APOPTOSIS PATIENTS MORTALITY
下载PDF
Numerical simulation of melt flow and temperature field during DC casting 2024 aluminium alloy under different casting conditions
7
作者 Jin-chuan Wang Yu-bo Zuo +3 位作者 Qing-feng Zhu Jing Li Rui Wang Xu-dong Liu 《China Foundry》 SCIE EI CAS CSCD 2024年第4期387-396,共10页
Casting speed,casting temperature and secondary cooling water flow rate are the main process parameters affecting the DC casting process.These parameters significantly influence the flow and temperature fields during ... Casting speed,casting temperature and secondary cooling water flow rate are the main process parameters affecting the DC casting process.These parameters significantly influence the flow and temperature fields during casting,which are crucial for the quality of the ingot and can determine the success or failure of the casting operation.Numerical simulation,with the advantages of low cost,rapid execution,and visualized results,is an important method to study and optimize the DC casting process.In the present work,a simulation model of DC casting 2024 aluminum alloy was established,and the reliability of the model was verified.Then,the influence of casting parameters on flow field and temperature field was studied in detail by numerical simulation method.Results show that with the increase of casting speed,the melt flow becomes faster,the depths of slurry zone and mushy zone increase,and the variation of slurry zone depth is greater than that of mushy zone.With an increase in casting temperature,the melt flow rate increases,the depth of the slurry zone becomes shallower,and the depth of the mushy zone experiences only minor changes.The simulation results further indicate that the increase of the flow rate of the secondary cooling water slightly reduces the depths of both slurry and mushy zone. 展开更多
关键词 aluminium DC casting flow field temperature field numerical simulation
下载PDF
Microstructural, wettability, and corrosion behaviour of TiO_(2) thin film sputtered on aluminium
8
作者 Rajeev VERMA Vijay KUMAR +2 位作者 Saurabh KANGO Amindra KHILLA Rajeev GUPTA 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第7期2210-2224,共15页
The study investigated the application of radiofrequency(RF)-sputtered TiO2 coatings at various temperatures to enhance the hydrophobicity and corrosion resistance of Al6061 alloy.The research aimed to establish a cor... The study investigated the application of radiofrequency(RF)-sputtered TiO2 coatings at various temperatures to enhance the hydrophobicity and corrosion resistance of Al6061 alloy.The research aimed to establish a correlation between the coating process and the resulting surface properties.Surface roughness and wettability were quantified with a surface profilometer and goniometer.Additionally,chemical boiling and salt spray corrosion tests were conducted to evaluate any topographical changes during these procedures.The analysis further involved the use of field-emission scanning electron microscopy(FESEM),energy-dispersive spectroscopy(EDS),and X-ray diffraction(XRD)techniques to characterize the deposited coatings.The findings indicated that the TiO2 coating applied at 500℃exhibited the highest water contact angle and superior corrosion resistance compared to other temperatures.Surface characterization confirmed that this specific TiO_(2) coating at 500℃ effectively delays corrosion due to its hydrophobic behavior,making it durable for industrial applications. 展开更多
关键词 aluminium TiO_(2) coating radiofrequency-sputtering HYDROPHOBIC corrosion
下载PDF
Static and Thermal Analysis of Aluminium (413,390,384 and 332) Piston Using Finite Element Method
9
作者 Offei David Inusah Jacob Kwaku Nkrumah Vincent Akolbire Atindana 《Modeling and Numerical Simulation of Material Science》 2024年第1期1-38,共38页
The main objective of this research was to examine the suitability of aluminium alloy to design a piston of an internal combustion engine for improvement in weight and cost reduction. The piston was modelled using Aut... The main objective of this research was to examine the suitability of aluminium alloy to design a piston of an internal combustion engine for improvement in weight and cost reduction. The piston was modelled using Autodesk Inventor 2017 software. The modelled piston was then imported into Ansys for further analysis. Static structural and thermal analysis were carried out on the pistons of the four different materials namely: Al 413 alloy, Al 384 alloy, Al 390 alloy and Al332 alloy to determine the total deformation, equivalent Von Mises stress, maximum shear stress, and the safety factor. The results of the study revealed that, aluminium 332 alloy piston deformed less compared to the deformations of aluminium 390 alloy piston, aluminium 384 alloy piston and aluminium 413 alloy piston. The induced Von Mises stresses in the pistons of the four different materials were found to be far lower than the yield strengths of all the materials. Hence, all the selected materials including the implementing material have equal properties to withstand the maximum gas load. All the selected materials were observed to have high thermal conductivity enough to be able to withstand the operating temperature in the engine cylinders. 展开更多
关键词 Von Mise stress Total deformation aluminium alloy Thermal analysis. PISTON Static structural Heat fux
下载PDF
Effectiveness of Sodium Silicate on the Corrosion Protection of AA7075-T6 Aluminium Alloy in Sodium Chloride Solution
10
作者 Francesco Rosalbino Giorgio Scavino Graziano Ubertalli 《Materials Sciences and Applications》 2024年第4期53-65,共13页
The influence of sodium silicate on the corrosion behaviour of aluminium alloy 7075-T6 in 0.1 M sodium chloride solution was studied by open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) tec... The influence of sodium silicate on the corrosion behaviour of aluminium alloy 7075-T6 in 0.1 M sodium chloride solution was studied by open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) techniques. Scanning electron microscopy (SEM) was used to characterize the AA7075-T6 surface. Silicate can significantly reduce corrosion deterioration and the inhibition efficiency increases with the concentration of Na<sub>2</sub>SiO<sub>3</sub>. The corrosion inhibition mechanism involves the formation of a protective film over the alloy surface by adsorption of aluminosilicate anions from solution, as has also been suggested by others in literature. 展开更多
关键词 aluminium Alloy 7075-T6 SILICATE Sodium Chloride Electrochemical Impedance Spectroscopy (EIS) Scanning Electron Microscopy (SEM)
下载PDF
Anti-tumor Effect and Protective Effect on Chemotherapeutic Damage of Water Soluble Extracts from Hedyotis diffusa 被引量:24
11
作者 李瑞 赵浩如 林以宁 《Journal of Chinese Pharmaceutical Sciences》 CAS 2002年第2期54-58,共5页
Bai-Hua-She-She-Cao Hedyotis diffusa Willd. (Ru-biaceae) is a medicinal herbwidely distributed in northeast Asian countries. In traditional Chinese medicine, it has the effectof 'clearing away heat and toxic mater... Bai-Hua-She-She-Cao Hedyotis diffusa Willd. (Ru-biaceae) is a medicinal herbwidely distributed in northeast Asian countries. In traditional Chinese medicine, it has the effectof 'clearing away heat and toxic material, promoting blood circulation and removing blood stasis'.It is a well known Chinese folk-medicine used for the treatment of appendicitis, sore throat, mumps,acne, sebo-rheic dermatitis and various kinds of tumors, such as tumors of digestive tract,carcinoma of liver. It was reported that the MeOH extract of H. diffusa demonstrated a significantantitumor activity and ursolic acid succeeded in being isolated from the MeOH extract as an activecomponent . Shan BN, et al suggested that the direct aqueous extract of H. diffusa hadimmuno-modulating activity and antitumor activity in vitro through stimulating the immune system tokill or engulf tumor cells. But regarding anti-tumor activity in vivo of water soluble extracts fromH. diffusa, no detail was reported. Therefore, we prepared water soluble extracts (H_1 and H_2)from H. diffusa and evaluated their anti-tumor property in vivo experiments as well as protectiveeffect on chemo-therapeutic damage. 展开更多
关键词 hedyotis diffusa water soluble extracts ANTI-TUMOR CHEMOTHERAPY
下载PDF
Effects of Cold Acclimation and CaCl_2 on Total Soluble Protein, CaM and Freezing Resistance of Populus tomentosa Seedlings 被引量:6
12
作者 林善枝 张志毅 《Forestry Studies in China》 CAS 2002年第1期5-12,共8页
Populus tomentosa seedlings used for cold acclimation at -3℃ were pretreated with or without 10?mmol·L -1 CaCl 2, 3?mmol·L -1 of Ca 2+ chelator EGTA, 0 1?mmol·L -1 of Ca 2+ ... Populus tomentosa seedlings used for cold acclimation at -3℃ were pretreated with or without 10?mmol·L -1 CaCl 2, 3?mmol·L -1 of Ca 2+ chelator EGTA, 0 1?mmol·L -1 of Ca 2+ channel inhibitor LaCl 3,and 0 05?mmol·L -1 of CaM antagonist CPZ. The changes in the contents of total soluble protein and CaM, and freezing resistance in all pretreated seedlings in various periods ( viz: following cold acclimation, chilling stress and recovery) were investigated. Results showed that cold acclimation increased the contents of total soluble protein and CaM, and freezing resistance of seedlings, which could be strongly reduced by the pretreatments of EGTA CPZ and LaCl 3 Cold acclimation combined with CaCl 2 pretreatment enhanced the effect of cold acclimation on freezing resistance, and obviously increased the contents of total soluble protein and CaM, reduced the declining degree of the contents of total soluble protein and CaM caused by chilling stress as compared with cold acclimation, augmented the increase in the level of total soluble protein and CaM during the recovery periods. Further analysis found that an increase in total soluble protein content during cold acclimation with or without CaCl 2 pretreatment mainly resulted from the increase in content of heat stable protein in total soluble protein. It is suggested that Ca 2+ calmodulin may be involved in the synthesis of total soluble protein, and the induction of freezing resistance of seedlings. 展开更多
关键词 Populus tomentosa cold acclimation CaCl 2 total soluble protein CAM freezing resistance
下载PDF
Cold Acclimation-Induced Changes in Total Soluble Protein, RNA, DNA, RNase and Freezing Resistance in Populus tomentosa Cuttings 被引量:3
13
作者 林善枝 张志毅 《Forestry Studies in China》 CAS 2002年第2期9-15,共7页
The changes in the contents of total soluble protein and RNA, the activity of RNase in leaves and branches of Populus tomentosa cuttings at various periods (viz: cold acclimation, deacclimation, chilling stress an... The changes in the contents of total soluble protein and RNA, the activity of RNase in leaves and branches of Populus tomentosa cuttings at various periods (viz: cold acclimation, deacclimation, chilling stress and the recovery after chilling stress), and the survival rate and the freezing resistance of cuttings during cold acclimation at -3℃ were investigated. Results showed that cold acclimation not only increased the contents of total soluble protein and RNA, the survival rates and the freezing resistance of cuttings, decreased the activity of RNase, but also reduced the declining degree of total soluble protein and RNA contents, and the increasing level of RNase caused by chilling stress as compared with the controls. In addition, cold acclimation augmented the increase in the level of total soluble protein and RNA, and facilitated the decrease of RNase during the recovery periods. Further analysis found that the DNA content of all treatments kept relative stability at various periods. The changes in total soluble protein, RNA and RNase were closely related to the freezing resistance of cuttings. It appears that the increase of RNA content caused by cold acclimation induced decrease of RNase activity may be involved in the accumulation of total soluble protein and the induction of freezing resistance of cuttings. 展开更多
关键词 Populus tomentosa cold acclimation freezing resistance total soluble protein nucleic acid
下载PDF
Photocatalytic Degradation of Water-Soluble Dyes by LaCoO_3 被引量:2
14
作者 杨秋华 傅希贤 秦永宁 《Transactions of Tianjin University》 EI CAS 2002年第2期83-86,共4页
Pervoskite type oxides LaCoO 3 was prepared by citrate method with the granula of 20 nm-30 nm. With a fluorescent Hg lamp or sunlight as irradiator, the degradation experiments of various water soluble dyes we... Pervoskite type oxides LaCoO 3 was prepared by citrate method with the granula of 20 nm-30 nm. With a fluorescent Hg lamp or sunlight as irradiator, the degradation experiments of various water soluble dyes were carried out in the suspension system of LaCoO 3 . The results show that the pervoskite type oxide LaCoO 3 has good photocatalytic activity.Studied by X ray photoelectron spectroscopy and photoacoustic spectra, its photocatalytic activity is found to be related with factors such as the d electron structure of ion Co 3+ ,Co—O binding energy and adsorbed oxygen on the surface etc. 展开更多
关键词 rare earths water soluble dye pervoskite type LaCoO 3 photocatalytic degradation
下载PDF
Extraction Efficiency of Soil Soluble Nitrogen under Different Conditions
15
作者 陈仕东 马红亮 +3 位作者 高人 阎聪微 李芳芳 李淑香 《Agricultural Science & Technology》 CAS 2012年第5期1040-1045,1080,共7页
[Objective] The extraction efficiency of soluble nitrogen in common moun- tain red soil under different conditions was analyzed to provide experimental refer- ences for the extraction of soil soluble nitrogen. [Method... [Objective] The extraction efficiency of soluble nitrogen in common moun- tain red soil under different conditions was analyzed to provide experimental refer- ences for the extraction of soil soluble nitrogen. [Method] The fresh soil and air-dried soil, which were the common mountain red soil under evergreen broad-leaved forest vegetation, were used as the experimental materials. The 2 mol/L KCI and 0.5 mol/L K2SO4 were used as the extractants to extract the soil soluble nitrogen with the extractant-to-soil volume ratio at 4:1, 6:1 and 10:1, respectively, to examine the extrac- tion efficiency of soluble nitrogen in the experimental soil with different extraction conditions. [Result] Compared with K2SO4, the NH4+-N extracted by KCI was better in quantity and stability; while only at high extractant-to-soil volume ratio could K2SO4 fully extract the soil NH4+-N. The 2 extractants showed small difference in extracting NO3--N, but at low extractant-to-soil volume ratio, the stability of NO3--N extracted by KCI was higher than that extracted by K2SO4. The properties of NO2- -N extracted by the 2 extractants were very similar. As for soil SON extraction, there was small dif- ference between the 2 extractants. However, the SON extracted by KCI was fewer in quantity than that by K2SO4, but had higher stability, and the extracted SON amount of the 2 extractants showed significant correlation. The extractant-to-soil ratio had little effect on MBN extraction using K2SO4, but the effect was significant when using KCI to extract MBN. The difference between the extraction efficiency of KCI and K^SO4 in extracting fresh soils was greater than that in extracting air-dried soil; therefore, the extractants should be carefully selected in soluble nitrogen extraction from fresh soil. [Conclusion] The results lay the experimental foundation for improving the extraction efficiency of soil soluble nitrogen and increasing the comparability of measurement results. 展开更多
关键词 EXTRACTANTS Extraction condition soluble nitrogen Red soil
下载PDF
Elementary study of differential expression of total soluble proteins in different life phases of Porphyra yezoensis
16
作者 孟春晓 高政权 +2 位作者 王依涛 罗韬 叶乃好 《Marine Science Bulletin》 CAS 2010年第2期32-37,共6页
Total soluble proteins of different life stages, filamentous sporophytes cultivated in high temperatures, and blade gametophytes harvested in different seasons, were identified by SDS-PAGE. The types and amounts of ex... Total soluble proteins of different life stages, filamentous sporophytes cultivated in high temperatures, and blade gametophytes harvested in different seasons, were identified by SDS-PAGE. The types and amounts of expressed proteins also varied amongst the samples. The fewest soluble proteins were present in filamentous sporophytes. There were more types and amounts of soluble protein in conchospores than in filamentous sporophytes, but fewer than in bulgy sporophytes. More types of protein were detected in filamentous sporophytes cultivated in high temperatures than in those growing in normal situations. The most types and amounts of protein were found in blade gametophytes in all samples. Blade gametophytes harvested last year and stored at -20 ℃ showed only minor differences in expression of proteins when compared with those harvested in different seasons. 展开更多
关键词 Porphyra yezoensis total soluble proteins differential expression
下载PDF
Effects of Different Nitrogen Fertilizer Rates on Soluble Sugar,Starch and Root Tissue Structure of the Peach Trees
17
作者 潘春香 肖艳辉 +1 位作者 新居直祐 中尾義則 《Agricultural Science & Technology》 CAS 2011年第12期1861-1863,共3页
[Objective] The research aimed to provide theoretical basis for the cultivation and production of peach.[Method] The three-year-old seedling peach tree was used as the materials,and NH4NO3 was used as the experimental... [Objective] The research aimed to provide theoretical basis for the cultivation and production of peach.[Method] The three-year-old seedling peach tree was used as the materials,and NH4NO3 was used as the experimental nitrogen fertilizer.Three nitrogen levels,0,3,6 g per pot respectively were set to study the effects of different nitrogen fertilizer on the contents of soluble sugar,starch and internal structure of the root of the peaches.[Result] The contents of soluble sugar of roots and leaves increased with the increase of nitrogen fertilizer level,and the level of 6 g per pot was the highest,which showed extreme differences between the level of 3 g per pot and the control.However,starch contents showed opposite results,which decreased as the level of nitrogen fertilizer increased.Compared with the 3 g per pot level of nitrogen fertilizer and the control,the internal structure of root applied with nitrogen fertilizer of 6 g per pot level had larger fibrovascularcylinder,advanced vascular bundle,small-spaced thin-walled cells,smooth and full cells with smooth cell wall.[Conclusion]Appropriate nitrogen levels can accelerate the accumulation of soluble sugar and the growth of root tissue structure. 展开更多
关键词 PEACH Nitrogen fertilizer rate soluble sugar STARCH Root tissue structure
下载PDF
Soluble organic nitrogen in forest soils of northeast China 被引量:4
18
作者 宋立臣 郝敬梅 崔晓阳 《Journal of Forestry Research》 SCIE CAS CSCD 2008年第1期53-57,共5页
Soluble organic nitrogen (SON) is recognized as a sensitive indicator of soil nitrogen status. The present work was conducted in the temperate forests of northeast China where soils are typically characterized by hi... Soluble organic nitrogen (SON) is recognized as a sensitive indicator of soil nitrogen status. The present work was conducted in the temperate forests of northeast China where soils are typically characterized by high organic matter and high organic nitrogen content, and soil sampling was made in early spring just after the freeze-thaw period. The water extracted SON pools in the organic layer of forest soils were measured within the range from 156.0 mg·kg^-1 to 292.6 mg·kg^-1, a similar magnitude of salt solution extracted SON pools reported in literatures. However, the water soluble SON pools in 0-15 cm mineral soils in present study were much higher (3-10 times) than any other reports, ranging from 58.6 mg·kg^-1 to 125.2 mg·kg^-1. Water soluble SON varied markedly among the soils under different forests and at different sites. The SON in water extracts were positively and significantly correlated to soil organic matter and total nitrogen contents, but negatively correlated to microbial biomass nitrogen (MBN). The reasons of the abnormally large SON pools and the negative correlations between SON and MBN in the 0-15cm mineral soils in this study were specially discussed. 展开更多
关键词 soluble organic nitrogen microbial nitrogen forest soil temperate forest Northeast China
下载PDF
A study of the properties of hydrophobically associating water-soluble polymers used in drilling fluids
19
作者 舒福昌 史茂勇 +4 位作者 张岩 张峰 黄红玺 向兴金 王建华 《Petroleum Science》 SCIE CAS CSCD 2004年第4期57-61,共5页
Hydrophobically associating water-soluble polymers (HPAP) have been synthesized from acrylamide(AM), acrylate (AA), 2-acrylamido-2-methyl propane sulfonic acid (AMPS) and hydrophobic monomer (AP) in aqueous solution... Hydrophobically associating water-soluble polymers (HPAP) have been synthesized from acrylamide(AM), acrylate (AA), 2-acrylamido-2-methyl propane sulfonic acid (AMPS) and hydrophobic monomer (AP) in aqueous solution by radical polymerization. New polymer drilling fluids are made up of HPAP, which is used as viscosifiers and encapsulation agents. Properties of this system are reported in this paper. Results indicate that this system has a high value of yield point to plastic viscosity (YP/PV≥0.7), high viscosity at a low-shear rate (LSRV≥30000mPa·s), excellent shear thinning behavior, good solid-carrying behavior, resistance to shear, good thermal stability (as high as 140℃) and salt resistance. The system has excellent behavior in high-density solution of NaCl and in calcium and magnesium rich saline solutions. Hence, HPAP also can be used in saltwater polymer drilling fluids. 展开更多
关键词 Hydrophobically associating water-soluble polymers drilling fluids VISCOSITY salt resistance
下载PDF
Solvent de binding of water soluble binder in powder injection moulding 被引量:14
20
作者 Li Songlin(李松林) Huang Baiyun(黄伯云) +1 位作者 Qu Xuanhui(曲选辉) Li Yimin(李益民) 《中国有色金属学会会刊:英文版》 EI CSCD 1999年第3期578-581,共4页
The solvent debinding of water soluble binder in powder injection moulding (MIM) was investigated systematically, including the effects of solvent types, temperature and the thickness of green parts on the solvent deb... The solvent debinding of water soluble binder in powder injection moulding (MIM) was investigated systematically, including the effects of solvent types, temperature and the thickness of green parts on the solvent debinding rate. After studying the debinding of a green part with a thickness of 4.26 mm, it was found that, the debinding rate of polyethylene glycol(PEG) in water and alcohol was high initially, and then decreased; however, it would increase with temperature increasing. At room temperature, the dissolution rate of PEG in water was higher than that in alcohol, but the latter would be much faster with temperature increasing because the debinding activation energy in alcohol was 51.44 kJ·mol -1 ·K -1 , much higher than 24.23 kJ·mol -1 ·K -1 in water. With a green part thickness larger than 4.26 mm, the debinding was controlled by diffusion; but with that smaller than 2.36 mm, the debinding was controlled by both dissolution and diffusion. 展开更多
关键词 powder injection MOULDING WATER soluble binders SOLVENT DEBINDING
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部