Mass spectroscopy

In this work, ZnFe2O4 nanoparticles were synthesized by hydrothermal method while the hummer method was used to synthesize GO nanosheet. GO/ZnFe2O4 nanocomposites (GO/ZFO) were prepared by mixing GO with ZnFe2O4 in mass ratio of 1:99, respectively.

8p viengfa 28-10-2024 3 1   Download

Unsaturated polyester resin (UPR) condensate water contains biodegradable organic compounds, including those that create unpleasant odor. Those odors can adversely impact the environment, human health, and, most of all, the uncomfortably.

7p vikwong 29-09-2024 3 1   Download

Trong báo cáo này, phương pháp phân tích Sắc ký khí ghép nối khối phổ (Gas Chromatography coupled Mass Spectroscopy - GC/MS) được sử dụng nhằm phân tích thành phần dạng khí sinh ra từ quá trình đốt cháy vải sợi cotton chưa qua xử lý, cũng như vải sợi cotton chống cháy xử lý bằng hệ phụ gia Pyrovatex CP, để từ đó thu được cái nhìn rõ nét hơn về tính an toàn của loại vật liệu này trong điều kiện sử dụng thực tế.

7p vimichaelfaraday 28-12-2023 9 5   Download

Effect of sodium nitrite on the carbon steel corrosion inhibition in the aerated neutral (pH 7) and alkaline (pH 11) water solutions at temperatures from 30o C to 140o C has been investigated by mass loss, potentiodynamic polarization and electrochemical impedance spectroscopy methods. Sodium nitrite was added in concentrations: 200, 350, 500, 750, 1000, 1500 and 2000 ppm by mass.

6p uocvong04 24-09-2015 34 4   Download

Kỹ thuật khối phổ hai lần MS/MS hay còn gọi là Tandem MS sử dụng phân mảnh bằng bắt giữ điện tử (Electron Capture Dessociation-ECD) đo trên thiết bị phổ khối cộng hưởng ion cyclotron có biến đổi Fourier (Fourier Transformation Ion Cyclotron Resonance Mass Spectroscopy -FT-ICR-MS) được ứng dụng như một giải pháp hữu hiệu trong nghiên cứu các phân tử sinh học có kích thước lớn và cấu trúc phức tạp như peptit và protein.

4p uocvong04 24-09-2015 60 3   Download

Colloidal silver nanoparticles were synthesized by
Co-60 ray irradiation of Ag+ in aqueous solution containing polyvinyl alcohol (PVA) as stabilizer and 0.5 M ethyl alcohol as free radical (OH• ) scavenger. The effect of Ag+ concentration which varied from 1 to 50 mM on the saturated conversion dose (D) of Ag+ into Ag determined by UV-vis spectroscopy and the size of Ag nanoparticles characterized by transmission electron microscopy (TEM) were investigated. The dependence of D (kGy) and average size (d, nm) of Ag nanoparticles on Ag+ concentration was found out to be as: D (kGy) = 0.

5p uocvong03 24-09-2015 36 4   Download

The structure of the O-polysaccharide of the lipopolysaccharide from a diarrheal strain isolated in Bangladesh was studied with sugar, and methylation analysis, NMR spectroscopy, mass spectrometry and partial acid hydrolysis. The strain was first designated as Hafnia alvei, but later found to be a possible new species in the genus Escherichia. Two different polysaccharides were detected, a major and a minor one. The structure of the major polysaccharide is given below, while the structure of the minor one was not investigated. ...

7p system191 01-06-2013 35 6   Download

The interaction of heat shock protein with molecular mass 25 kDa (HSP25) and its point mutants S77D + S81D (2D mutant) and S15D + S77D + S81D (3D mutant) with intact and thermally denatured actinwas analyzedbymeans of fluorescence spectroscopy and ultracentrifugation. Wild typeHSP25 did not affect the polymerization of intact actin. The HSP25 3D mutant decreased the initial rate without affecting the maximal extent of intact actin polymerization. G-actin heated at 40–45
C was partially denatured, but retained its ability to polymerize....

10p tumor12 20-04-2013 27 4   Download

ThecellwallofBrevibacteriumsp. VKM Ac-2118 isolated from a frozen (mean annual temperature)12
C) late Plio-cene layer, 1.8–3 Myr, Kolyma lowland, Russia, contains mannitol teichoic acidwith a previously unknown structure. This is 1,6-poly(mannitol phosphate) with the majority of the mannitol residues bearing side phosphate groups at O-4(3). The structure of the polymer was established by chemical methods, NMR spectroscopy, and MALDI-TOF mass spectrometry.

6p fptmusic 12-04-2013 39 3   Download

The polar glycolipids were isolated from the thermophilic bacteriaMeiothermus taiwanensisATCC BAA-400 by eth-anol extraction and purified by Sephadex LH-20 and silica gel column chromatography. The fatty acid composition of O-acyl groups in the glycolipids was obtained by gas chro-matography mass spectroscopy analysis on their methyl esters derived from methanolysis and was made mainly of C15:0(34.0%) andC17:0(42.3%) fattyacids,withthemajority as branched fatty acids (over 80%).

7p awards 05-04-2013 41 1   Download

An open reading frame (Acc. no. P50740) on theBacillus subtilis chromosome extending from bp 184 997–186 043 with similarity to theidi-2 gene ofStreptomycessp. CL190 specifying type II isopentenyl diphosphate isomerase was expressed in a recombinant Escherichia colistrain. The recombinant protein with a subunit mass of 39 kDa was purified to apparent homogeneity by column chromatog-raphy. The protein was shown to catalyse the conversion of dimethylallyl diphosphate into isopentenyl diphosphate and vice versa at rates of 0.23 and 0.

12p dell39 03-04-2013 44 4   Download

Thioredoxin reductase (TrxR) fromEscherichia coli,the mutant proteins E159Y and C138S, and the mutant protein C138Streated with phenylmercuric acetate were reconstituted with [U-13 C17 ,U-15 N4]FAD and analysed, in their oxidized and reduced states, by 13 C-, 15 N- and 31 P-NMR spectroscopy. The enzymes studied showed very similar 31 P-NMR spectra in the oxidized state, con-sisting of two peaks at )9.8 and )11.5 p.p.m. In the reduced state, the two peaks merge into one apparent peak (at)9.8 p.p.m.)....

16p dell39 03-04-2013 43 4   Download

We have isolated a nonfucosylated and three variously fucosylated neutral oligosaccharides from human milk that are based on theiso-lacto-N-octaose core. Their structures were characterized by the combined use of electrospray mass spectrometry (ES-MS) and NMR spectroscopy. The branching pattern and blood group-related Lewis deter-minants, together with partial sequences and linkages of these oligosaccharides, were initially elucidated by high-sensitivity ES-MS/MS analysis, and then their full structure assignment was completed by methylation analysis and 1 H-NMR.

15p dell39 03-04-2013 60 3   Download

The effects of high hydrostatic pressure (HHP) and urea on conformational transitions of humana-thrombin structure were studiedbyfluorescence spectroscopy andbymeasuring the catalytic activity of the enzyme. Treatment of thrombin with urea produced a progressive red shift in the center of mass of the intrinsic fluorescence emission spectrum, with a maximum displacement of 650 cm )1 . HHP (270 MPa) shifted the centre ofmass by only 370 cm )1 .HHP combined with a subdenaturing urea concentration (1.5M) displaced the centre of mass by
750 cm )1 ....

8p dell39 03-04-2013 27 3   Download

The intracellular accumulation of low molecular mass organic compounds in response to stressful conditions was investigated in the thermophilic bacterium Petrotoga miotherma, a member of the order Thermotogales. This led to the discovery of a new solute, whose structure was established as a-d-mannopyranosyl-(1fi2)-a-d-glucopyranosyl-(1 fi2)-glycerate (MGG) by MMR spectroscopy and MS.

8p galaxyss3 19-03-2013 24 4   Download

Synthetic hyaluronan oligosaccharides with defined structures and their pyridylaminated derivatives were used to investigate the mechanism of hydrolysis of hyaluronan by bovine testicular hyaluronidase. The products of the hydrolysis were analyzed by HPLC and ion-spray mass spectroscopy (MS).

11p mobifone23 18-01-2013 58 3   Download