Journal of biochemical and biophysical methods最新文献_第4页

Assessment of pelt quality in leather making using a novel non-invasive sensing approach 用一种新颖的非侵入式传感方法评估皮革生产中的毛皮质量

Journal of biochemical and biophysical methods Pub Date : 2008-04-24 Epub Date: 2007-07-17 DOI: 10.1016/j.jbbm.2007.07.003

S.C. Mukhopadhyay , S. Deb Choudhury , T. Allsop , V. Kasturi , G.E. Norris

引用次数: 39

Fatty acid composition of triacylglycerols from Wharton's jelly determined by high-performance liquid chromatography 高效液相色谱法测定华顿果冻中三酰基甘油的脂肪酸组成

Journal of biochemical and biophysical methods Pub Date : 2008-04-24 Epub Date: 2007-09-21 DOI: 10.1016/j.jbbm.2007.09.004

Lech Romanowicz , Zofia Galewska , Tomasz Gogiel , Stefan Jaworski , Krzysztof Sobolewski

{"title":"Fatty acid composition of triacylglycerols from Wharton's jelly determined by high-performance liquid chromatography","authors":"Lech Romanowicz , Zofia Galewska , Tomasz Gogiel , Stefan Jaworski , Krzysztof Sobolewski","doi":"10.1016/j.jbbm.2007.09.004","DOIUrl":"10.1016/j.jbbm.2007.09.004","url":null,"abstract":"<div><p>The improved method for HPLC determination of fatty acids was proposed. The chromatographic separation of <em>p</em>-bromophenacyl derivatives of fatty acids under a gradient elution was achieved at 40 °C with an RP-18 LiChroCART 5 column and organic mobile phase containing methanol, acetonitrile, water and TEAP buffer pH 5.6. The quantitative determination of those derivatives was performed at 254 nm. Preeclampsia, the most common pregnancy complication, did not affect triacylglycerol content in the umbilical cord Wharton's jelly in comparison to the control material. However, it changed the composition of fatty acids, bound to that lipid class. The method allows the determination of almost all fatty acids forming the investigated neutral lipid class, contained in a solid tissue sample. The use of TEAP buffer excluded precipitation and flow stoppage in the HPLC system. The method reduced time and costs and might be useful for all other lipid classes and different tissues.</p></div>","PeriodicalId":15257,"journal":{"name":"Journal of biochemical and biophysical methods","volume":"70 6","pages":"Pages 973-977"},"PeriodicalIF":0.0,"publicationDate":"2008-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.jbbm.2007.09.004","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"27026286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 14

Biomolecules/gold nanowires-doped sol–gel film for label-free electrochemical immunoassay of testosterone 生物分子/金纳米线掺杂溶胶-凝胶膜用于睾酮的无标记电化学免疫分析

Journal of biochemical and biophysical methods Pub Date : 2008-04-24 Epub Date: 2007-11-24 DOI: 10.1016/j.jprot.2007.11.007

Ke-Zhong Liang , Jun-Sheng Qi , Wei-Jun Mu , Zai-Gang Chen

{"title":"Biomolecules/gold nanowires-doped sol–gel film for label-free electrochemical immunoassay of testosterone","authors":"Ke-Zhong Liang , Jun-Sheng Qi , Wei-Jun Mu , Zai-Gang Chen","doi":"10.1016/j.jprot.2007.11.007","DOIUrl":"10.1016/j.jprot.2007.11.007","url":null,"abstract":"<div><p>A direct, rapid, and label-free electrochemical immunoassay method for testosterone has been described based on encapsulating testosterone antibody into polyvinyl butyral sol–gel film doped with gold nanowires. Gold nanowires prepared by using nanopore polycarbonate membrane were used to conjugate testosterone antibody onto the probe surface. The presence of gold nanowires provided a biocompatible microenvironment for biomolecules, greatly amplified the immobilized amount of biomolecules on the electrode surface, and improved the sensitivity of the immunosensor. In comparison with gold nanoparticle-conjugating probe, the gold nanowire-functionalized probe could avoid the leakage of biomolecules from the composite film, and enhanced the stability of the sensor. The performance and factors influencing the performance of the resulting immunosensor were investigated in detail. Under optimal conditions, the developed immunosensor exhibited a good linear relationship with testosterone ranging from 1.2 to 83.5 ng mL<sup>−1</sup> with a detection limit of 0.1 ng mL<sup>−1</sup> (at 3<em>δ</em>). Moreover, the proposed immunosensor exhibited high sensitivity, good reproducibility and long-term stability. The as-prepared immunosensors were used to analyze testosterone in human serum specimens. Analytical results suggest that the developed immunoassay has a promising alternative approach for detecting testosterone in the clinical diagnosis. Compared with the conventional ELISAs, the proposed immunoassay method was simple and rapid without multiple labeling and separation steps. Importantly, the route provides an alternative approach to incorporate gold nanowires into the solid matrix for biosensing application.</p></div>","PeriodicalId":15257,"journal":{"name":"Journal of biochemical and biophysical methods","volume":"70 6","pages":"Pages 1156-1162"},"PeriodicalIF":0.0,"publicationDate":"2008-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.jprot.2007.11.007","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"27188532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 54

A method to fabricate mesoscopic freestanding polydimethylsiloxane membranes used to probe the rheology of an epithelial sheet 一种制备介观独立聚二甲基硅氧烷膜的方法，用于探测上皮片的流变学

Journal of biochemical and biophysical methods Pub Date : 2008-04-24 Epub Date: 2007-08-01 DOI: 10.1016/j.jbbm.2007.07.005

John C. Selby , Mark A. Shannon

{"title":"A method to fabricate mesoscopic freestanding polydimethylsiloxane membranes used to probe the rheology of an epithelial sheet","authors":"John C. Selby , Mark A. Shannon","doi":"10.1016/j.jbbm.2007.07.005","DOIUrl":"10.1016/j.jbbm.2007.07.005","url":null,"abstract":"<div><p>Details are presented for the formulation, fabrication, and mechanical characterization of mesoscopic freestanding polydimethylsiloxane (PDMS) elastomer membranes, 10.0 μm thick and 5.0 mm in diameter, used to probe the rheology of a living epithelial sheet. In what is described as a composite diaphragm inflation (CDI) experiment, freestanding PDMS membranes are utilized as substrates for the culture of a sheet of epithelial cells. Together, the cell layer and the PDMS elastomer form a composite diaphragm (CD) that is suitable for mechanical testing in an axisymmetric membrane inflation experiment. In order to distinguish the rheological behavior of the epithelial sheet from the mechanical response of the elastomer using inflation test data, freestanding PDMS membranes should exhibit a highly compliant yet mechanically invariant finite load-deformation response when subjected to multiple inflation cycles following intermittent periods of cell culture. Given these considerations, we describe a method for preparing freestanding PDMS elastomer membrane specimens that are optically transparent, tensed, and wrinkle-free. Surface modifications intended to facilitate cell culture, namely water vapor plasma and ultraviolet light treatments, were shown to dramatically stiffen the mechanical response of the membranes, rendering them unusable as CD substrates. In this study, only PDMS membranes with physiosorbed collagen demonstrated the mechanical compliance, fatigue resistance, and environmental stability necessary for reliable use in CDI experiments.</p></div>","PeriodicalId":15257,"journal":{"name":"Journal of biochemical and biophysical methods","volume":"70 6","pages":"Pages 932-944"},"PeriodicalIF":0.0,"publicationDate":"2008-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.jbbm.2007.07.005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"26946955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 17

Enantiorecognition of triiodothyronine and thyroxine enantiomers using different chiral selectors by HPLC and micro-HPLC 不同手性选择剂对三碘甲状腺原氨酸和甲状腺素对映体的高效液相色谱和微高效液相色谱识别

Journal of biochemical and biophysical methods Pub Date : 2008-04-24 Epub Date: 2007-10-05 DOI: 10.1016/j.jbbm.2007.09.007

Julia Koidl, Heike Hödl, Martin G. Schmid, Bianca Neubauer, Marlene Konrad, Sabine Petschauer, Gerald Gübitz

{"title":"Enantiorecognition of triiodothyronine and thyroxine enantiomers using different chiral selectors by HPLC and micro-HPLC","authors":"Julia Koidl, Heike Hödl, Martin G. Schmid, Bianca Neubauer, Marlene Konrad, Sabine Petschauer, Gerald Gübitz","doi":"10.1016/j.jbbm.2007.09.007","DOIUrl":"10.1016/j.jbbm.2007.09.007","url":null,"abstract":"<div><p>This paper deals with the chiral separation of triiodothyronine (T<sub>3</sub>) and thyroxine (T<sub>4</sub>) by HPLC and micro-HPLC. The separation of T<sub>3</sub> and T<sub>4</sub> is of great pharmaceutical and clinical interest, since the enantiomers exhibit different pharmacological activities. The HPLC measurements were performed on a chiral stationary ligand-exchange phase using <span>l</span>-4-hydroxyproline bonded via 3-glycidoxypropyltrimethoxysilane to silica gel as a selector. Also a chiral teicoplanin (Chirobiotic ™®) phase was used.</p><p>In micro-HPLC the chiral separation behaviour of <span>l</span>-4-hydroxyproline, and of the macrocyclic antibiotics teicoplanin and teicoplanin aglycone was investigated for the enantioseparation of T<sub>3</sub> and T<sub>4</sub>. <span>l</span>-4-Hydroxyproline was bonded to 3 μm and the glycopeptide antibiotics were bonded to 3.5 μm silica gel and separations were accomplished by microbore HPLC columns (10 cm×1 mm I.D.). With both techniques and all chiral selectors investigated T<sub>3</sub> and T<sub>4</sub> were baseline resolved. micro-HPLC was found to be superior to analytical HPLC with respect to low consumption of packing material, mobile phase and analyte.</p></div>","PeriodicalId":15257,"journal":{"name":"Journal of biochemical and biophysical methods","volume":"70 6","pages":"Pages 1254-1260"},"PeriodicalIF":0.0,"publicationDate":"2008-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.jbbm.2007.09.007","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41012945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 20

Investigation of hydrocarbon fractions form waste plastic recycling by FTIR, GC, EDXRFS and SEC techniques 利用FTIR、GC、EDXRFS和SEC技术研究废塑料回收中烃类组分

Journal of biochemical and biophysical methods Pub Date : 2008-04-24 Epub Date: 2007-05-29 DOI: 10.1016/j.jbbm.2007.05.005

N. Miskolczi, L. Bartha

{"title":"Investigation of hydrocarbon fractions form waste plastic recycling by FTIR, GC, EDXRFS and SEC techniques","authors":"N. Miskolczi, L. Bartha","doi":"10.1016/j.jbbm.2007.05.005","DOIUrl":"10.1016/j.jbbm.2007.05.005","url":null,"abstract":"<div><p>Waste high-density polyethylene was converted into different hydrocarbon fractions by thermal and thermo-catalytic batch cracking. For the catalytic degradation of waste plastics three different catalysts (equilibrium FCC, HZSM-5 and clinoptilolite) were used. Catalysts differ basically in their costs and activity due to the differences of micro- and macroporous surface areas and furthermore the Si/Al ratio and acidities are also different. Mild pyrolysis was used at 430 °C and the reaction time was 45 min in each case. The composition of products was defined by gas chromatography, Fourier transform infrared spectroscopy, size exclusion chromatography, energy-dispersive X-ray fluorescence spectroscopy and other standardized methods. The effects of catalysts on the properties of degradation products were investigated. Both FCC and clinoptilolite catalysts had considerably catalytic activity to produce light hydrocarbon liquids, while HZSM-5 catalyst produced the highest amount of gaseous products. In case of liquids, carbon numbers were distributed within the C<sub>5</sub>–C<sub>23</sub> range depending on the cracking parameters. Decomposition of the carbon chain could be followed by GC and both by FTIR and SEC techniques in case of volatile fractions and residues. Catalysts increased yields of valuable volatile fractions and moreover catalysts caused both carbon chain isomerization and switching of the position of double bonds.</p></div>","PeriodicalId":15257,"journal":{"name":"Journal of biochemical and biophysical methods","volume":"70 6","pages":"Pages 1247-1253"},"PeriodicalIF":0.0,"publicationDate":"2008-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.jbbm.2007.05.005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"26806264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 31

A procedure for the rapid screening of Maillard reaction inhibitors 美拉德反应抑制剂的快速筛选方法

Journal of biochemical and biophysical methods Pub Date : 2008-04-24 Epub Date: 2007-11-12 DOI: 10.1016/j.jprot.2007.10.002

Shamila Fatima , Deeba S. Jairajpuri , M. Saleemuddin

{"title":"A procedure for the rapid screening of Maillard reaction inhibitors","authors":"Shamila Fatima , Deeba S. Jairajpuri , M. Saleemuddin","doi":"10.1016/j.jprot.2007.10.002","DOIUrl":"10.1016/j.jprot.2007.10.002","url":null,"abstract":"<div><p>A procedure for the rapid screening of inhibitors of glycation reaction, based on their ability to protect RNase against sugar induced inactivation of the enzyme is described. Glycation is implicated in variety of disorders including diabetes, atherosclerosis various micropathies yet is a slow process both in vivo and in vitro. In order to speed up glycation, the reaction was carried out at 60 °C using a thermostable protein RNase and ribose, a sugar that is known to react rapidly than glucose in the glycation reaction. It was observed that incubation of RNase with ribose at 60 °C in rapid inactivation of the enzyme with a parallel decrease in tyrosine fluorescence, enhancement in new fluorescence and hyperchromicity in the UV-region. No such alterations in the enzyme activity were observed when the incubation was carried out in absence of the sugar. Compounds and drugs that are known to act as inhibitors of glycation reaction restricted the ribose-induced inactivation of RNase. RNase immobilized on CNBr-activated Sepharose was also sensitive to exposure to ribose and appeared a better system to screen inhibitors of glycation from natural sources that contain substances that interfere with the assay of enzyme as well as in the study of post Amadori inhibitors of glycation.</p></div>","PeriodicalId":15257,"journal":{"name":"Journal of biochemical and biophysical methods","volume":"70 6","pages":"Pages 958-965"},"PeriodicalIF":0.0,"publicationDate":"2008-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.jprot.2007.10.002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"27131914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 11

Evaluation of electron spin resonance for studies of superoxide anion production by human neutrophils interacting with Staphylococcus aureus and Staphylococcus epidermidis 电子自旋共振对人类中性粒细胞与金黄色葡萄球菌和表皮葡萄球菌相互作用产生超氧阴离子研究的评价

Journal of biochemical and biophysical methods Pub Date : 2008-04-24 Epub Date: 2007-06-09 DOI: 10.1016/j.jbbm.2007.05.014

Helen Lundqvist , Staffan Dånmark , Uno Johansson , Håkan Gustafsson , Karin Öllinger

{"title":"Evaluation of electron spin resonance for studies of superoxide anion production by human neutrophils interacting with Staphylococcus aureus and Staphylococcus epidermidis","authors":"Helen Lundqvist , Staffan Dånmark , Uno Johansson , Håkan Gustafsson , Karin Öllinger","doi":"10.1016/j.jbbm.2007.05.014","DOIUrl":"10.1016/j.jbbm.2007.05.014","url":null,"abstract":"<div><p>The present study evaluates electron spin resonance (ESR) and the spin trapper 5-(diethoxyphosphoryl)-5-methyl-1-pyrroline-<em>N</em>-oxide (DEPMPO) for analysis of superoxide radical production by human neutrophils interacting with viable <em>Staphylococcus aureus</em> and <em>Staphylococcus epidermidis</em> bacteria. To avoid auto-activation due to interaction with glass surfaces, neutrophils were preincubated in plastic tubes until the peak response was reached, and then transferred to a quartz flat cell to record the ESR spectra. The time point for peak response was identified by parallel analysis of the bacteria–neutrophil interaction using luminol amplified chemiluminescence. We found detectable ESR spectra from neutrophils interacting with as few as five bacteria of the weak activating <em>S. epidermidis</em> per neutrophil. Addition of the NADPH oxidase inhibitor diphenylene iodonium totally abolished spectra. Catalase, DMSO or an iron chelator had no impact on the produced spectra and ionomycin, a selective activator of intracellular NADPH oxidase, gave significant ESR spectra. Taken together, our results indicate that DEPMPO is cell permeable and detects NADPH oxidase derived superoxide anions formed in phagosomes or released by human neutrophils phagocytosing viable <em>S. aureus</em> and <em>S. epidermidis</em>. The technique may be used as a sensitive tool to evaluate superoxide anion production in human neutrophils.</p></div>","PeriodicalId":15257,"journal":{"name":"Journal of biochemical and biophysical methods","volume":"70 6","pages":"Pages 1059-1065"},"PeriodicalIF":0.0,"publicationDate":"2008-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.jbbm.2007.05.014","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"26807006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 9

Improving the refolding of NTA protein by urea gradient and arginine gradient size-exclusion chromatography 尿素梯度和精氨酸梯度排阻色谱法改善NTA蛋白的再折叠

Journal of biochemical and biophysical methods Pub Date : 2008-04-24 Epub Date: 2008-01-07 DOI: 10.1016/j.jprot.2007.12.004

Xiangdong Fan, DianSheng Xu, Bing Lu, Jie `Xia, Dongzhi Wei

引用次数: 13

A steered molecular dynamics method with direction optimization and its applications on ligand molecule dissociation 方向优化导向分子动力学方法及其在配体分子解离中的应用

Journal of biochemical and biophysical methods Pub Date : 2008-04-24 Epub Date: 2007-10-24 DOI: 10.1016/j.jbbm.2007.10.006

Xinli Liu , Xicheng Wang , Huangliang Jiang

引用次数: 18