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1.
The interaction of indophenol blue (IPB) with proteins in aqueous solution has been studied by optical absorption and Rayleigh light scattering (RLS) spectroscopy. At pH 3.8, the weak RLS of IPB is enhanced by proteins. Based on this phenomenon, a novel method for the determination of proteins at nanogram levels using the RLS technique is developed. The method is simple, practical and sensitive. The linear range is 0.25–20.9µgmL–1 for BSA, and 0.25–17.6µgmL–1 for HSA. The detection limits (S/N=3) are 23ngmL–1 for BSA and 22ngmL–1 for HAS. The results for the determination of proteins in human serum samples are very close to those obtained by an established clinical method. There is very little interference from amino acids, metal ions or other coexisting compounds.  相似文献   

2.
Conclusions The reaction of,-unsaturated aldehydes with cyanohydrins in the presence of tertiary amines, leading to esters of cyanohydrins, proceeds through the formation of the cyanohydrin of an,-unsaturated aldehyde, followed by intramolecular prototropic 1,3-shift (75–80%), the formation of a ketonitrile, and conversion of the latter to an ester.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 581–586, March, 1970.  相似文献   

3.
An ESR study has shown that under the action of oxygen pulses, radical ions O 2 with gI=2.0085 and gII=2.087 are generated at room temperature on the surface of 1% CoO–MgO. Heating of the sample to 150 °C in the spectrometer results in complete disappearance of the O 2 signal from the ESR spectra. The variation of the O 2 signal intensity with time due to the interaction between propene and oxygen adsorbed on the sample surface, has been measured.
, 1% CoO–MgO - O 2 gI=2.0085 gII=2.087. 150 °C - O 2 . O 2 .
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4.
The heat capacity of high-purity indium has been determined by adiabatic-shield calorimetry in the range 300 to 1000 K. Values of thermodynamic functions have been calculated andC p (1000 K), [H° (1000 K)– (298.15 K)], and [S° (1000 K)–S° (298.15 K)] are (27.11±0.15) J K–1 mole–1, (22873±70) J mole–1, and (41.567 ±0.125) J K–1 mole–1, respectively. The enthalpy of fusion is (3283±7) J mole–1 and the melting temperature (429.77±0.01) K. The premelting heat capacity is compatible with the presence of a mole fractionx 1·10–6 of a liquid-soluble/solidinsoluble impurity in the sample.
Zusammenfassung Die Wärmekapazität von hochreinem Indium wurde im Bereich von 300 bis 1000 K durch adiabatische Schildkalorimetrie bestimmt. Die Berechnungen der thermodynamischen Funktionen:C p (1000 K), [H° (1000 K)–H° (298.15 K)] und [S° (1000 K–S° (298.15 K)] ergab 27.11±0.15 J K–1 Mol–1, (22 875±70) J Mol–1, bzw. (41.567±0.125) J K–1 Mol–1. Die Schmelzenthalpie beträgt (3283±7) J Mol–1 und die Schmelztemperatur (429.77±0.01) K. Die Vorschmelz-Wärmekapazität ist mit der Gegenwart einer Molfraktionx1×10–6 einer flüssig-löslich/fest-unlöslichen Verunreinigung in der Probe vereinbar.

Résumé La chaleur spécifique de l'indium de haute pureté a été déterminée entre 300 et 1000 K par calorimétrie adiabatique. Les valeurs des fonctions thermodynamiques suivantes ont été calculées:C p (1000 K)=(27.11±0.15) J K–1mol–1, [H° (1000 K)–H° (298.15 K)]= (22 875±70) J mol–1 et [S° (1000 K)–S° (298.15 K)]=(41.567±0.125) J K–1 mol–1. L'enthalpie de fusion est (3283±7) J mol–1 et la température de fusion (429.77±0.01) K. La chaleur spécifique de pré-fusion est compatible avec la présence d'une fraction molairex1×10–6 d'une impureté dans l'échantillon, soluble dans le liquide, insoluble dans le solide.

C - 300 1000 . : p(1000 ), [ (1000 ) — H (298,15 )] [S (1000 ) — S (298.15 )], : 27.11±0.15 . –1. –1, 2 2875±70 . –1 41.567±0.125 . – 1–1. 3283±7 .–1, – 429.77±0,01 . - / 1.10–6.


The assistance of Bjørn Lyng Nielsen with the experimental work is recognized with thanks.  相似文献   

5.
Kinetic regularities in the consumption of initial reactants and the accumulation of propylene oxidation products has been studied in the region of negative temperature coefficients of the maximum reaction rate (T=648–723 K). It has been revealed that for prolynene-enriched mixtures (C3H6:O2=3:1) at P-20.66 kPa, the reaction rate is practically independent of the temperature, whereas for poor mixtures (C3H6:O2=1:5) it decreases with increasing temperature.
a (T=648–723K). , (C3H6:O2=3:1) P=20,66 , (C3H6:O2=1:5) .
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6.
Two steroid glycosides of the spirostan series — nicotianosides A and B — and one glycoside of the furostan series — nicotianoside E — have been isolated from the seeds ofNicotiana tabacum L. Nicotianoside A is (25S)-5-spirostan-3-ol 3-O--D-glucopyranoside, nicotianoside B is (25S)-5-spirostan-3-ol 3-O-[O--L-rhamnopyranosyl-(12)-gb-D-glucopyranoside], and nicotianoside E is (25S)-5-furostan-3,22,26-triol 26-O--glucopyranoside 3-O-[O--L-rhamnopyranosyl-(12)--D-glucopyranoside].Institute of Genetics, Academy of Sciences of the Republic of Moldava, Kishinev, ul. Lesnaya, 20. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 737–742, November–December, 1994.  相似文献   

7.
Zusammenfassung Hartelastische Polymere, insbesondere hartelastisches Polypropylen (HEPP) zeigen neuartige mechanische Eigenschaften, die sich durch zwei hintereinandergeschaltete Kelvin-Elemente im wesentlichen beschreiben lassen. Die nachgewiesene Affintransformation bei der Verstreckung vereinfacht die Verhältnisse in entscheidender Weise. Das eine Kelvin-Element besteht aus einer Feder mit der FederkonstanteE und parallel geschaltetem Dämpfer mit der Viskosität, das andere aus einem Adhäsionsglied mit der rücktreibenden KraftK 1, und einem parallel geschaltetem Reibungselement mit dem Reibungskoeffizienten Die Röntgenäquatorkleinwinkelstreuung verrät bei Verstreckung sich bildende Zwischenräume zwischen den Lamellen, deren Dickenzunahme gleich ist der wachsenden Langperiode, wobei in diesen Zwischenräumen unabhängig vom Verstreckungsgrad 50 Å dicke Fibrillen mit einem mittleren Abstand von 115 Å entstehen. Ihr hieraus berechnetes Gesamtvolumen ergibt sich auch aus Kernresonanzmessungen von bei — 60°C verstrecktem HEPP. Die bei konstanter Verstreckungsgeschwindigkeitv und anschließender Verkürzungsgeschwindigkeit —v aufgenommenen Kraft-DehnungskurvenK() zeigen sechs charakteristische Einzelabschnitte. Nach dem pseudo-Hooke'schen Anlaufgebiet, bedingt durch die RuhreibungK a von treten zwei exponentiell sich einstellende Abschnitte 3 und 5 auf mit ähnlicher-Halbwertsbreite von 0 0,5 beim Verstrecken und 0 0,2 beim Zurückfahren. Auf Abschnitt 3 folgt ein Plateau, dessen Höhe vonv nur ganz wenig abhängt und eine gleitende Reibungv verrät. Die Durchrechnung zeigt, daß auch die 0-Halbwertsbreiten durchv bestimmt sind. Die atomare Erklärung für die zurücktreibende KraftK 1, vom zweiten Kelvin-Element ergibt sich durch eine an den lateralen Fibrillenoberflächen auftretenden Oberflächenenergie l von 60 erg /cm2 und eine bei Verstreckung an den Fibrillenaustrittsstellen auftretende Reibungv = 1,5 × 107 dyn beiv = 1,5 × 10–4 cm/sek undv = 2,3 × 107 dyn beiv = 1,5 × 10–2 cm/sek bei einer Präparatdicke von 0,03 cm2 und einer Präparatlänge von 5,2 cm. Dies entspricht Austrittseschwindigkeiten von 6 × 10–3 Å/sek bzw. 6 × 10–1 Å/sek der Mikrofibrillen an den Mikroparakristalloberflächen. Die geringev-Abhängigkeit vonv verrit den Charakter einer gleitenden Reibung. Die Ruhreibung für dieses Präparat beträgt stets etwa 1,5 × 107 dyn; die Adhäsionsspannung einer Mikrofibrille beträgt allgemein 5 × 108 dyn/cm2.
Summary Hard elastic fibers, especially hard elastic polypropylene (HEPP) show novel mechanical properties which can be described with two Kelvin-elements in series. The affine transformation of the shape of the sample during straining simplifies the situation decisively. One of the Kelvin-elements consists of a spring-constantE, parallel with a dashpot with the viscosity. The other consists of an adhesive term with a retractive forceK 1, in parallel with a friction term with the friction coefficient The small angle X-ray scattering on the equator reveals during straining an opening of gaps between lamellae. The increase of these gaps equals the increase of the long period. The gaps are bridged, independent from straining, by 50 Å thick fibrils with a mean distance of 115 Å. Their total volume calculated from these data is in good agreement with the results obtained from nuclear magnetic resonance (NMR) measurements on HEPP fibers strained at — 60°C. The stress-strain diagrams taken with constant strain velocitiesv and following destraining velocities —v show six characteristic sections. After the first pseudo-Hooke'ian section, limited by the static friction Ka, appear two exponential sections 3 and 5 with almost the same 0-half width of 0 0,5 at straining and 0 0,2 at destraining. Section 3 is followed by a plateau varying only slightly, withv and reveals the sliding frictionv The calculations show that the 0-half widths are determined also byv. An explanation in atomic scale for the driving forceK 1 of the second Kelvin element is the lateral surface free energy of the fibrils L of 60 erg cm–2 and a sliding frictionv = 15 × 107 dyn atv = 1,5 × 10–4 cm/sec andv = 2,3 × 107 dyn atv = 1,5 × 10–2 cm/sec for a fibril which is 5,2 long at the beginning. The values imply a constant cross-section of the sample of 0,03 cm3. The relatively small dependence ofv onv reveals that it is a sliding friction with extruding velocities of 6 × 10–3 Å/sec resp. 6 × 10–1 Å/sec of the microfibrils from the lateral boundaries of the microparacrystals. The static friction of this sample isK a = 1,5 × 107 dyn, corresponding to an absolute value of 5 × 108 dyn cm–2 for the adhesive stress of on microfibril.
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8.
The known triterpene glycosides hederagenin 3-O--L-arabinopyranoside, hederagenin 3-O-\-D-glucopyranoside, oleanolic acid 3-O--sophoroside, hederagenin 3-O--sophoroside, and their 28-O--gentiobiosyl esters, respectively, in addition to the new triterpene glycoside 3-O--sophorosyl-28-O--L-rhamnopyranosyl-(14)-O--gentiobiosyl hederagenin are isolated fromFatsia japonica (Araliaceae) seeds. The structures of these glycosides are established using chemical and spectral methods.Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 131–133, March–April, 2000.  相似文献   

9.
The thermal decomposition of binary copolymers of acrylonitrile with variable amounts of -methylstyrene (2–40%) has been studied atp=10–2–10–4 torr andT=0–600°. The decomposition products (solids, liquids and gases) have been characterized by IR and UV spectroscopy, gas chromatography, vapor pressure osmometry and elemental analysis. The decomposition mechanism has been ascertained on the basis of the obtained results.
Zusammenfassung Die thermische Zersetzung der binären Kopolymere von Akrylnitril mit verschiedenen Mengen von -Methylstyrol (2–40%) wurde beip=10–2–10–4 Torr undT=0–600° untersucht. Die Zersetzungsprodukte (Festkörper, Flüssigkeiten und Gase) wurden durch IR- und UV-Spektroskopie, Gaschromatographie, Dampfdruck-Osmometrie und Elementaranalyse charakterisiert. Der Zersetzungsmechanismus wurde an Hand der erhaltenen Ergebnisse bestätigt.

Résumé On a étudié la décomposition thermique des copolymères binaires de l'acrylonitrile avec des quantités variables d'-méthylstyrène (2–40%), àp=10–2–10–4 torr etT=0–600°. Les produits de décomposition (solides, liquides et gaz) ont été caractérisés par spectroscopie IR et UV, Chromatographie en phase gazeuse, osmométrie sous pression de vapeur et analyse élémentaire. Le méchanisme de décomposition a été établi à partir des résultats obtenus.

(2–40%) - p=10–2–10–4 =0–600°. (, ) - - , , . .
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10.
Three different binding states of CO on cobalt surfaces have been identified by TPD studies. The energetics of these adsorption states and their relevance in Fischer-Tropsch synthesis are considered.
CO - . -.
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11.
A novel method for the determination of proteins in aqueous solutions has been developed based on the enhancement of resonance light scattering (RLS) of Ag nanoparticles in the presence of proteins. Factors including acidity of the media, concentration of Ag hydrosol, reaction time, temperature, and interference of non-protein substances were investigated. Under the optimal conditions, with the enhanced RLS signals at 452nm, the linear ranges of calibration curves were 0–0.8µgmL–1 for bovine serum albumin (BSA), 0–1.2µgmL–1 for human serum albumin (HSA), and 0–2.5µgmL–1 for human -IgG (-IgG), respectively. The detection limits were 1.3ngmL–1 for BSA, 10ngmL–1 for HAS, and 5.7ngmL–1 for -IgG.This method has been applied to the analysis of synthetic samples and real human serum samples, and the results were in good agreement with those reported by the hospital, indicating that the method presented here is not only sensitive and simple, but also reliable and suitable for practical applications.  相似文献   

12.
Two new glycosides have been isolated from the seeds ofCoronilla glauca L. and C. scorpioides Koch: 3-(0-D-glucopyranosyloxy)-14. 15-dihydroxy-19-oxo-5-card-20(22)-enolide (alloglaucoside) and 3-(-D-gluco-ucofuranosyloxy)-5,14,19-trihydroxy-5-card-20(22)-enolide (scorpiosidol), together with a glycoside previously unknown for theCoronilla genus — 3-(-D-glucopyranosylo)g)-14-hydroxy-5-card-20(22)-enolide (desglucouzarin) and known aglycons (corotoxigenin, alloglaucotoxigenin, coroglaucigenin) and glycosides (glucocorotoxigenin, coronillobioside, glucocoroglaucigenin, coronillobiosidol and scorpioside).Ukraine Pharmaceutical Academy, Kharkov–2. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 372–376, May–June, 1996. Original article submitted August 14, 1995.  相似文献   

13.
A new triterpene glycoside — cucamarioside G1 — has been isolated from the Pacific Ocean holothurianCucumaria fraudatrix. On the basis of physicochemical characteristics and the results of chemical transformations, its structure has been established as 16-acetoxy-3-[O-(3-O-methyl--D-xylopyranosyl)-(1 3)-O--D-glucopyranosyl-(1 4)--D-quinovopyranosyl-(1 2)-(4-O-sulfato--D-xylopyranosyloxy)]-holosta-7,24-diene.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 244–248, March–April, 1985.  相似文献   

14.
Summary From a methanolic extract of the skins of the bulbs ofAllium giganteum Rgl, a new steroid glycoside has been isolated — aginoside, which is (25R)-5-spirostan-2, 3, 6-triol 3-0-{[0--D-xylopyranosyl-(13)-]-[0--D-glucopyranosyl-(12)]-0--D-glucopyranosyl-(14)-0--D-galactopyranoside}.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 480–486, July–August, 1976.  相似文献   

15.
Two known compounds of the cycloartane series—cyclosieversiosides C and G—and the new glycoside cycloglobiceposide B—24R-cycloartane-3,6,16,24,25-pentaol 16,25-di-O--D-glucopyranoside 3-O--D-xylopyranoside—have been isolated from the roots ofAstragalus globiceps Bunge. The structures of the glycosides were established on the basis of the results of enzymatic and total hydrolysis and also of1H and13C NMR spectra.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (371) 120 64 75. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 216–219, March–April, 1999.  相似文献   

16.
The structures of four triterpene glycosides from the leaves ofScheffleropsis angkae (Araliaceae) are found by chemical methods and NMR spectroscopy to be the 3-O--L-arabinopyranosides of oleanic and ursolic acids and their 28-O--L-rhamnopyranosyl-(14)-O--gentiobiosyl esters, which are designated L-B1, L-B2, L-H1, and L-H2, respectively. The glycoside L-H2 is new.Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 136–138, March–April, 2000.  相似文献   

17.
Granular activated carbon loaded with aniline,o-nitroaniline oro-nitrophenol, regenerated at relatively low temperature (450° in N2 atmosphere), shows losses of cyclic adsorption performances (about 5 % per cycle) comparable to those occurring with standard thermal regeneration (950° in controlled atmosphere). Adsorbate build-ups and related surface modifications have been determined.
Zusammenfassung Mit Anilin,o-Nitroanilin undo-Nitrophenol beladene, bei relativ niedriger Temperatur (450° in N2-Atmosphäre) regenerierte granulierte Aktivkohle, zeigt zyklische Verluste der Adsorptionsleistung (etwa 5 % je Zyklus), welche mit den bei thermischer Standard-Regenerierung (950° in gesteuerter Atmosphäre) vorkommenden vergleichbar sind. Der Aufbau der Adsorbate und die damit verbundenen Oberflächenänderungen wurden bestimmt.

Résumé Le charbon actif en granulés, chargé d'aniline, d'o-nitroaniline et d'o-nitrophénol, régénéré à une température relativement faible (450° dans une atmosphère d'azote) montre des pertes de rendement d'adsorption cyclique (environ 5 p.c. par cycle) comparables à celles qui ont lieu lors de la régénération thermique standard (950° en atmosphère contrôlée). On a déterminé la constitution des adsorbats et les modifications relatives de surface.

, , -, - – 450° . , ( 5% ) – 950° . .


Work supported by IRSA-CNR, contract no. 77.01823.11.

Thanks are due to Mr. L. Pace for skilful contribution to the experimental work.  相似文献   

18.
A new glycoside of the cycloartane series — askendoside C — has been isolated from the roots of the plantAstragalus taschkendicus Bge., and its structure has been established on the basis of chemical transformations and spectral characteristics as 24R-cycloartane-3,6,16,24,25-pentaol 3-[0--L-arabinopyranosyl-(12)--D-xylopyranoside].Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 173–180, March–April, 1983.  相似文献   

19.
The determination of trace metals, e.g. Bi, Cd, Pb, in high-purity aluminium, zinc and commercial steel by flame or graphite furnace atomic absorption spectrometry following their preconcentrations as iodo complexes on XAD-1180 resin by means of a short column system is described. The recoveries are quantitative (95%). The relative standard deviations varies between 6% and 10%. The relative errors are less than 8% in a concentration range of 1 × 10–3 –4 × 10–5%. Detection limits for flame AAS and GFAAS were in the ranges of 0.002–0.110 g/ml and 0.0003–0.004 g/ml or in the ranges of 0.08–4.40 g/g and 0.012–0.16 g/g with respect to the solid samples, respectively.  相似文献   

20.
Summary Bifunctional methylenebis(diphenylphosphine oxide) (mdpo) on reaction with iron(III) perchlorate forms the complex, [Fe(mdpo)3](ClO4)3 · H2O. This has been characterized through elemental analysis, i.r., far-i.r., u.v. and visible spectroscopy and by x-ray diffraction, magnetic moment, molar conductance and e.s.r. data. The e.s.r. spectrum consists of five lines with transitions from: ¦–5/2¦–3/2¦–3/2¦–1/2, ¦–1/2¦+1/2¦+1/2¦+3/2 and ¦+3/2¦+5/2 centred at a g-value of 2.00. On the basis of these studies, a chelated octahedral structure has been assigned to the cation, [Fe(mdpo)3]3+.  相似文献   

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