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1.
Molecular Diversity - The antifungals that are in current clinical practice have a high occurrence of a side effect and multidrug resistance (MDR). Researchers across the globe are trying to... 相似文献
2.
The occurrence of charge on recoil56Mn produced by the (n,γ) reaction in polycrystalline potassium permanganate has been examined using the ‘charge plate technique’.
From considerations of capture gamma ray decay schemes and internal conversion it appears that, in a condensed medium, the
recoil atom develops charge after losing much of its initial kinetic energy which allows collection on charged electrodes.
Preliminary findings were presented at the International Symposium on Radiochemistry and Radiation Chemistry, RC-41 BARC,
Bombay, Feb. 4–6 (1991). 相似文献
3.
The present paper deals with the study of a Durrmeyer-type integral modification of certain modified Baskakov operators. Here
we study simultaneous approximation properties for these operators by using the iterative combinations. We obtain an asymptotic
formula and an error estimation in terms of higher order modulus of continuity for these operators.
相似文献
4.
Boruah A Rao IN Nandy JP Kumar SK Kunwar AC Iqbal J 《The Journal of organic chemistry》2003,68(12):5006-5008
A cis-proline derived cyclic mimic of a type VI beta-turn is synthesized via a ring-closing metathesis reaction. The solution NMR conformational study indicates that the major conformer of the cyclic peptide adopts a type VIa beta-turn in CDCl(3) and a type VIb beta-turn in DMSO-d(6). 相似文献
5.
Nandy JP Prabhakaran EN Kumar SK Kunwar AC Iqbal J 《The Journal of organic chemistry》2003,68(5):1679-1692
A novel chemo- and diastereoselective aerobic epoxidation of the N-cinnamoyl peptides catalyzed by polyaniline-supported cobalt(II) salen (PASCOS) is described. The N-cinnamoyl proline derived peptides 1 show a high pi-facial selectivity during these epoxidations. The origin of this diastereoselectivity in 1 has been attributed to (i) the propensity of the N-cinnamoyl proline amide to exist predominantly as trans rotamer in CDCl3, DMSO-d6, and CH3CN medium and (ii) existence of these peptides as organized structures (gamma- and beta-turns) due to the presence of intramolecular hydrogen bonds. An extensive solution NMR and MD simulation study on 1d and 1f indicates that the origin of the high pi-facial selectivity is due to the well-defined gamma- and beta-turns which result in the hindrance of one face of the cinnamoyl double bond in the transition state of the epoxidation reaction. 相似文献
6.
S. P. Mishra /Miss/ Jyoti Singh 《Journal of Radioanalytical and Nuclear Chemistry》1986,105(2):107-116
Fractional precipitation techniques have been utilized to separate the lower valent and parent forms of56Mn in permanganate targets and an attempt is made to study a few aspects of chemical stabilization of recoil56Mn in permanganates. Ammonium permanganate, recoil behaviour of which has not been studied previously, is chosen as one of the targets along with the potassium permanganate for initial retention and also for isothermal annealing.56Mn initial retentions of about 12% and about 4% are obtained for potassium and ammonium permanganate, respectively, by activation from a Ra–Be neutron source. A usual trend for KMnO4 and the reduction of recoil fragments by ammonium ions in NH4MnO4 are seen through the isothermal annealing study. 相似文献
7.
Carlo Gioeli Neil Balgobin Staffan Josephson Jyoti B. Chattopadhyaya 《Tetrahedron letters》1981,22(10):969-972
2-(Trimethylsilyl)ethyl chloroformate reacts with alcohols to give carbonates in high yield. n-Bu4NF in THF(0.2M) solution for 10 min or ZnBr2 or ZnCl2 in CH3NO2 for 10 min regenerate the alcohol at 20°C. 相似文献
8.
Summary A nitrate-selective electrode based on precipitated nitron nitrate in an epoxy resin matrix has been prepared. The lower detection limit is 10–5
M, the optimum pH range is 2.0–8.5, and the response time is 1 min. The electrode is selective in presence of CH3COO–, SO4
2–, C2O4
2–, PO4
3–, NO2
–, Cl– and Br–, but I– interferes. Results for nitrate in soil samples were in agreement with values obtained spectrophotometrically.
Presented at the 8th International Microchemical Symposium, Graz, August 25–30, 1980. 相似文献
Eine neue nitrat-spezifische Elektrode auf der Basis gefällten Nitronnitrats
Zusammenfassung Eine nitrat-spezifische Elektrode auf der Basis gefällten Nitronnitrats in einer Epoxyharz-Matrix wurde hergestellt. Die untere Nachweisgrenze ist 10–5 M, das pH-Optimum liegt zwischen 2,0 und 8,5, die Reaktionszeit beträgt 1 Minute. Die Elektrode ist selektiv in Gegenwart von Acetat, Sulfat, Oxalat, Phosphat, Nitrit, Chlorid und Bromid; aber Jodid stört. Ergebnisse der Nitratbestimmung in Bodenproben stimmen mit spektrophotometrischen Resultaten überein.
Presented at the 8th International Microchemical Symposium, Graz, August 25–30, 1980. 相似文献
9.
Organoboron derivatives of biologically potent β‐enamino esters of the type [Where R = CH3(1a), C2H5 (1b), C3H7(1c) and C (CH3)3 (1d)] have been prepared by the reactions of β‐enamino esters and Phenyl boronic acid [PhB (OH)2] in 1:2 molar ratio in refluxing tetrahydrofuran (THF). All these derivatives have been characterized by physico‐chemical properties, elemental analyses and molecular weight measurements. The structures of these compounds have been proposed on the basis of IR, 1H, 13C, 11B NMR spectral data and GC‐mass spectrometry. Phenyl boronic acid, β‐enamino esters and their respective phenylboronates derivatives have been screened for the antibmicrobial activities against pathogenic bacteria (B. subtilis and E. coli) and fungi (A. niger and P. peniculosum) to access their growth inhibiting potential. In addition to this, antiandrogenic effect of Ligand, LaH2 and its boron derivative (1a) has also been tested in male albino rats. 相似文献
10.
Rakesh?Kumar?MahajanEmail author Jyoti?Chawla Mandeep?Singh?BakshiEmail author 《Colloid and polymer science》2004,282(10):1165-1168
Cloud point (CP) measurements of Tween 20 and Tween 80 were carried out in the presence of various glycol oligomers and triblock polymers (TBP). The cloud points of both Tween 20 and 80 decrease in the presence of both types of additives. Among the glycol oligomeric additives, ethylene glycol monobutyl ether was found to reduce the CP maximum. An increase in the repeating units of polymeric glycol additives leads to a decrease in CP. Reduction in the CP in the presence of TBP depends upon the increase in hydrophobic/hydrophilic ratio among the polypropylene to polyethylene units. 相似文献