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排序方式: 共有153条查询结果,搜索用时 15 毫秒
11.
Mulder P Hemmink S De Heer MI Lupo M Santoro D Korth HG 《The Journal of organic chemistry》2001,66(20):6611-6619
In the presence of hydrogen donor solvents and at elevated temperatures, aromatic ketones can be selectively deoxygenated to the corresponding hydroaromatic compounds. The kinetics for reduction of 7H-benz[d,e]anthracen-7-one (benzanthrone, 6) into 7H-benz[d,e]anthracene (benzanthrene, 1) in 9,10-dihydroanthracene (3) solvent has been investigated in detail. The relatively slow hydrogenation of 6 is due to reversibility of the initial hydrogen-transfer step according to a reverse radical disproportionation (RRD). The dynamics could well be rationalized using the energetics of species computed by density functional theory (DFT). The application of hydrogen donors such as 1 as a hydrogen-transfer agent, although favorable in terms of a low benzylic carbon-hydrogen bond dissociation enthalpy, is limited due to the slow self-hydrogenation, which in case of 1 gives 5,6-dihydro-4H-benz[d,e]anthracene (7). 相似文献
12.
Effectiveness of Photodynamic Therapy in Elimination of HPV‐16 and HPV‐18 Associated with CIN I in Mexican Women
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Elizabeth Maldonado Alvarado Martha Olivia Osorio Peralta Alejandra Moreno Vázquez Lydia Alejandra Martínez Guzmán Maria Eugenia Melo Petrone Zulma Iveth Enriquez Mar Dora Estela Jovel Galdamez Bárbara Carrión Solana Guadalupe Balderas Martínez Eduarda Parra Rossana Inés Castellanos Oliveros Rosa Linda Bello Leiva Araceli Espinosa Montesinos Citlalli Barrera Mendoza Selma Eugenia Medina García Eva Ramón Gallegos 《Photochemistry and photobiology》2017,93(5):1269-1275
This study aimed to determine the effectiveness of photodynamic therapy (PDT), using δ‐aminolevulinic acid (5‐ALA), in the elimination of premalignant cervical lesions in Mexican patients with human papillomavirus (HPV) infection and/or cervical intraepithelial neoplasia (CIN). Thirty women diagnosed with CIN I and/or positive for HPV participated in the study. Topical 6% 5‐ALA in gel form was applied to the uterine cervix; after 4 h, the lesion area was irradiated with a light dose of 200 J cm?2 at 635 nm. This procedure was performed three times at 48‐h intervals. Clinical follow‐up was performed at 3, 6, and 12 months after the initial PDT administration, by colposcopy, cervical cytology, histopathological analysis, polymerase chain reaction, and hybrid capture. Of HPV‐infected patients without evidence of CIN I, 80% cleared the infection, while HPV associated with CIN I was eliminated in 83% of patients (P < 0.05). At 12 months, CIN I had regressed in 57% of patients, although this response was not statistically significant. PDT using 6% 5‐ALA is concluded to be effective in eliminating HPV infection associated or not with CIN I. 相似文献
13.
Abstract Let X be a non–hyperelliptic curve of genus g which is a double covering of a hyperelliptic curve C of genus h. In this paper, we prove that, if h≥ 3 and g≥ 4h+5, then X admits a complete, base point free g1g–2. Moreover, if h=3, this result holds under the mild condition g≥ 4h+3=15.
Keywords: Double covering of hyperelliptic curves, Pencil of degree g–2
Mathematics Subject Classification (2000:) 14H30, 14H45 相似文献
14.
We solve a half-line problem for a nonlinear diffusion equation with a given time-dependent thermal conductivity at the origin.
The problem reduces to a linear Volterra integral equation, which is solvable by Picard’s process of successive approximations.
We analyze some explicit examples numerically.
__________
Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 152, No. 1, pp. 58–65, July, 2007. 相似文献
15.
Mohamed AA Ricci S Burini A Galassi R Santini C Chiarella GM Melgarejo DY Fackler JP 《Inorganic chemistry》2011,50(3):1014-1020
Halide-centered hexanuclear, anionic copper(II) pyrazolate complexes [trans-Cu(6)((3,5-CF(3))(2)pz)(6)(OH)(6)X](-), X = Cl, Br, I are isolated in a good yield from the redox reaction of the trinuclear copper(I) pyrazolate complex [μ-Cu(3)((3,5-CF(3))(2)pz)(3)] with a halide source such as PPh(3)AuCl or [Bu(4)N]X, X = Cl, Br, or I, in air. X-ray structures of the anion-centered hexanuclear complexes show that the six copper atoms are bridged by bis(3,5-trifluoromethyl)pyrazolate and hydroxyl ligands above and below the six copper atom plane. The anions are located at the center of the cavity and weakly bound to the six copper atoms in a μ(6)-arrangement, Cu-X = ~3.1 ?. A nitrite-centered hexanuclear copper(II) pyrazolate complex [trans-Cu(6)((3,5-CF(3))(2)pz)(6)(OH)(6)(NO(2))](-) was obtained when a solution of [PPN]NO(2) in CH(3)CN was added dropwise to the trinuclear copper(I) pyrazolate complex [μ-Cu(3)((3,5-CF(3))(2)pz)(3)] dissolved in CH(3)CN, in air. Blue crystals are produced by slow evaporation of the acetonitrile solvent. The X-ray structure of [PPN][trans-Cu(6)((3,5-CF(3))(2)pz)(6)(OH)(6)(NO(2))] complex shows the nitrite anion sits in the hexanuclear cavity and is perpendicular to the copper plane with a O-N-O angle of 118.3(7)°. The (19)F and (1)H NMR of the pyrazolate ring atoms are sensitive to the anion present in the ring. Anion exchange of the NO(2)(-) by Cl(-) can be observed easily by (1)H NMR. 相似文献
16.
17.
Letf: X → Y be a dominant map between real algebraic varieties of the same dimension. The object of this paper is the study of the map
which sends every pointy ∈ Y to the number of real points inf
−1 (y). We give a sufficient condition ony to ensure that the above map is locally constant iny. Moreover, we consider the subset ofY where this map is no more locally constant and we give the principal properties of this set.
The work was written while both the authors were members of the G.N.S.A.G.A. of the Consiglio Nazionale delle Ricerche. 相似文献
Sunto Siaf: X → Y un morfismo dominante tra varietà algebriche reali della stessa dimensione. In questo articolo si studia la mappa che associa ad ogni puntoy ∈ Y il numero di punti reali inf −1 (y); in particolare si dà una condizione sufficiente suy affinchè tale mappa sia costante in un suo intorno. Inoltre, si considera il sottoinsieme diY in cui tale mappa non è più localmente costante e si danno le principali proprietà di tale insieme.
The work was written while both the authors were members of the G.N.S.A.G.A. of the Consiglio Nazionale delle Ricerche. 相似文献
18.
The oxa-di-π-methane (ODPM) photorearrangement of 2-(carbomethoxy)spiro [5.5]undeca-1,3-diene-7-one (d) to d and the latter's thermal rearrangement to d were shown to be not only fully regio-and stereoselective but also to occur with complete enantiospecificity. An additional example, the 2-hydroxymethyl derivative (f) was also studied and the two systems were chemically correlated. 相似文献
19.
20.
Concetta Cafiero Agnese Re Egidio Stigliano Ezio Bassotti Rossana Moroni Cristina Grippaudo 《Electrophoresis》2019,40(14):1820-1823
Efficient DNA extraction procedures is a critical step involved in the process of successful DNA analysis of such samples. Various protocols have been devised for the genomic DNA extraction from human tissues and forensic stains, such as dental tissue that is the skeletal part that better preserves DNA over time. However DNA recovery is low and protocols require labor‐intensive and time‐consuming step prior to isolating genetic material. Herein, we describe an extremely fast procedure of DNA extraction from teeth compared to classical method. Sixteen teeth of 100‐year‐old human remains were divided into two groups of 8 teeth and we compared DNA yield, in term of quantity and quality, starting from two different sample preparation steps. Specifically, teeth of group 1 were treated with a classic technique based on several steps of pulverization and decalcification, while teeth of group 2 were processed following a new procedure to withdraw dental pulp. In the next phase, the samples of both group underwent the same procedure of extraction, quantification and DNA profile analysis. Our findings provide an alternative protocol to obtain a higher amount of good quality DNA in a fast time procedure, helpful for forensic and anthropological studies. 相似文献