bluuebunny/crossref_metadata_2025_split huggingface dataset:
Origin and relation of three kinds of scatter centers in KDP and DKDP crystals
Authors: Sun X. , Wang Z. P. , Wang S. L. , Gu Q. T. , Xu X. G. , Li Y. P. , Fang C. S. 
Published: August 2004

AbstractThe origin of three kinds of scatter centers in KDP and DKDP crystals and their relations were investigated. The results have shown that solid inclusions will form liquid and gas inclusions in KDP (DKDP) crystals. The effect of scatter centers on Laser Damage Threshold of the crystals is not same because their sizes are different. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Infrared photoluminescence from TlGaS2 layered single crystals
Authors: Yuksek N. S. , Gasanly N. M. , Aydinli A. , Ozkan H. , Acikgoz M. 
Published: August 2004

AbstractPhotolimuniscence (PL) spectra of TlGaS2 layered crystals were studied in the wavelength region 500‐1400 nm and in the temperature range 15‐115 K. We observed three broad bands centered at 568 nm (A‐band), 718 nm (B‐band) and 1102 nm (C‐band) in the PL spectrum. The observed bands have half‐widths of 0.221, 0.258 and 0.067 eV for A‐, B‐, and C‐bands, respectively. The increase of the emission band half‐width, the blue shift of the emission band peak energy and the quenching of the PL with increasing temperature are explained using the configuration coordinate model. We have also studied the variations of emission band intensity versus excitation laser intensity in the range from 0.4 to 19.5 W cm‐2. The proposed energy‐level diagram allows us to interpret the recombination processes in TlGaS2 crystals. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
X‐ray powder diffraction study of the semiconducting alloy Cu2Cd0.5Mn0.5GeSe4
Authors: Delgado G. E. , Quintero E. , Tovar R. , Quintero M. 
Published: August 2004

AbstractThe structure of the semiconducting alloy Cu2Cd0.5Mn0.5GeSe4 was refined from an X‐ray powder diffraction pattern using the Rietveld method. The present alloy crystallizes in the wurtz‐stannite structure, space group Pmn21 (No 31), and unit cell parameters values of a = 8.0253(2) Å, b = 6.8591(2) Å, c = 6.5734(2) Å and V = 361.84(2) Å3. The structure exhibits a three‐dimensional arrangement of slightly distorted CuSe4, Cd(Mn)Se4 and GeSe4 tetrahedras connected by corners. © 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim
Crystal and molecular structure of 3‐phenyl‐4‐(p‐chlorobenzylamino)‐4,5‐dihydro‐1‐H‐1,2,4‐triazol‐5‐on
Authors: Yilmaz V. T. , Agar E. , Guven K. , Kahveci B. , Sasmaz S. 
Published: August 2004

AbstractThe structure of the title compound, C15H13N4OCl was determined by single crystal X‐ray diffraction technique. The structure consists of a p‐chlorobenzylamino moiety and triazol and phenyl rings. The title compound crystallizes in the monoclinic space group P21/c with a = 14.368(3), b = 6.255(3), c = 17.631(3) Å, β = 113.24(3)°, Z = 4, V = 1455.8(8) Å3 and Dx = 1.372 gcm‐3. The structure was solved by direct methods and refined by full‐matrix least‐squares method (R=0.0477). The dihedral angle between the triazole moiety and the phenyl ring is 28.8(3)°. The molecular packing is stabilized by N‐H…N and N‐H…O types of inter molecular hydrogen bonds. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Crystal structure of 1,4‐dihydroxy‐3,4‐dibromo‐1,2,3,4‐tetrahydro‐naphthalene
Authors: Öztürk S. , Büyükkįdan B. , Erenler R. , Akkurt M. , Çakmak O. , Fun H.‐K. 
Published: August 2004

AbstractThe title compound (C10H10O2Br2 ) crystallizes in the orthorhombic space group P212121 with a = 5.0319(2)Å, b = 13.5282(5)Å, c = 15.6289(6)Å, V = 1063.90(1) Å3, Z = 4, Dx = 2.01 g/cm3 at T = 293(2) K. The structure was solved by direct methods and refined by full‐matrix least‐squares procedures to final R = 0.078 and wR = 0.140 using 1212 observed reflections with [I ≥ 2σ(I)]. The title compound as a whole is not planar. The crystal structure is stabilized by hydrogen contacts and weak van der Waals interactions. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Crystal structure of 2,6‐diphenyl azabicyclo [3.3.1] nonan‐9‐one thiosemicarbazone
Authors: Sampath N. , Malathy Sony S. M. , Ponnuswamy M. N. , Nethaji M. 
Published: August 2004

AbstractThe title compound (C21H24N4S, CCDC 206345) crystallizes in triclinic space group P&#38;1macr; with cell parameters a =12.557(2) Å, b = 12.743(2) Å, c = 13.703(2) Å, α =90.005(3)°, β = 113.663(3)°, γ = 106.756(3)°, V = 1906.2(5) Å3, Z = 4, Dcal = 1.270 Mg/m3 at T =293 K. The structure was solved by direct methods and refined by full‐matrix least‐squares procedures to a final R1= 0.0573and wR2 = 0.1364 using 8192 observed reflections. The piperidine and cyclohexane rings adopt chair conformation. The planar phenyl rings are the equatorial substituents of the piperidine ring. The molecules in the unit cell are stabilized by N‐H…N, N‐H…S & C‐H…π intra and intermolecular hydrogen bond networks in addition to van der Waals forces. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fractal processing for an analysis of the quality and resistivity of large semiconductor plates
Authors: Yücel Kurt H. , Kurt E. , Salamov B. G. 
Published: August 2004

AbstractA nondestructive method is suggested for the analysis of the quality and resistivity inhomogeneity of semiconductor plates in an ionization system with a SI GaAs semiconductor plate. At the same time, a device for rapid visualization and recording the resistance inhomogeneity and photoconductivity distribution throughout the bulk material in high‐resistivity and photosensitive semiconductor plates of large diameter (50‐100 mm) is described. Semiconductor plates with the resistivity from 105 to 109 Ωcm can be analyzed in the proposed device. The possibilities of the device have been evaluated, i.e. a relative change of the resistance inhomogeneity is determined by a relative change of discharge light emission intensity when a current is passed through an ionization cell. For the quantitative analysis of quality and resistivity inhomogeneity of semiconductor plates, fractal dimension analysis was used following the records of the discharge light emission intensity. The quality of plates was analyzed using both the profile and spatial distributed light emission intensity data showing the internal inhomogeneity in the semiconductor plate. Thus, by using fractal concept, the surface quality of the high‐resistivity semiconductor plate can be assessed exactly and the size and location of the internal inhomogeneities in the semiconductor plate to be ascertained. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Diffusion couple studies of the Ti‐Bi‐Zn system
Authors: Vassilev G. P. 
Published: August 2004

AbstractThe system Ti‐Bi‐Zn has been investigated using diffusion couples consisting of solid Ti and liquid (Bi+Zn) phase. The diffusion paths at 400, 500, 700 and 800 °C have been traced by means of electron microprobe analyses. The growth constants of the diffusion layers are roughly assessed. The phase diagram data obtained in this investigation are compared with previous studies of equilibrated alloys. The existence of the ternary compound TiBiZn has been confirmed. The formation of another phase with approximate formulae Ti4Bi3Zn to Ti9Bi7Zn4 has been observed at high temperatures. The latter compound as well as the ternary extension of the TiXBiY (X ≈ 5, Y ≈ 6) phase react easily with air. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Affinity of single S. cerevisiae cells to 2‐NBDglucose under changing substrate concentrations
Authors: Achilles J. , Müller S. , Bley T. , Babel W. 
Published: August 2004

AbstractBackgroundSaccharomyces cerevisiae is a widely employed microorganism in biotechnological processes. Since proliferation and product formation depend on the capacity of the cell to access and metabolize a carbon source, a technique was developed to enable for analyzing the S. cerevisiae H155 cells' affinity to extracellular glucose concentrations.MethodsThe fluorescent glucose analogue 2‐NBDglucose was employed as a functional parameter to analyze the cells' affinity to glucose. Structural parameters (proliferation, neutral lipid content, granularity, and cell size) were also investigated. Cells were grown both in batches and in chemostat regimes.ResultsThe 2‐NBDglucose uptake in individual cells proceeds in a time‐ and concentration‐dependent manner and is affected by respiratory and respirofermentative modes of growth. The process is inhibited by D‐glucose, D‐fructose, D‐mannose, and sucrose, but not L‐glucose, D‐galactose or lactose; maltose is a weak inhibitor. The affinity of the individual cells to 2‐NBDglucose was found to be high at low extracellular glucose concentrations, and weak at high concentrations. An additional, underlying pattern in the cells' affinity to glucose was detected, illustrated by the recurrent appearance of two subpopulations showing distinctly differing quantities of this substrate.ConclusionsA multiparameter flow cytometry approach is presented that enables, for the first time, for analysis of the affinity of individual S. cerevisiae cells to glucose. Besides the adjustment of the yeast cell metabolism to extracellular glucose concentrations by altering their affinity to glucose, at least one further mechanism is clearly involved. Two subpopulations of cells were resolved, with different affinities not correlated with other cellular parameters measured. © 2004 Wiley‐Liss, Inc.
Coexpression of p53 protein and MDR functional phenotype in leukemias: The predominant association in chronic myeloid leukemia
Authors: Cavalcanti Geraldo Barroso , Vasconcelos Flavia da Cunha , de Faria Giselle Pinto , Scheiner Marcos Antônio Maurício , Dobbin Jane de Almeida , Klumb Claudete Esteves , Maia Raquel C. 
Published: August 2004

AbstractBackgroundOne of the best characterized resistance mechanisms of leukemias is multidrug resistance (MDR) mediated by P‐glycoprotein (Pgp) and multidrug‐resistant related protein (MRP). In addition to Pgp and MRP, p53 mutation or inactivation might play a relevant role in therapeutic failure. Some studies have demonstrated that Pgp and MRP may be activated in association with overexpression of mutant or inactivated p53 protein. The aim of this study was to investigate the association between p53 expression and MDR functional phenotype analyzed by flow cytometry (FCM).MethodsRhodamine‐123 assay analyzed by FCM was used to detect the MDR phenotype that was positive in 18 out of 41 (43.9%) cases of chronic myeloid leukemia (CML), 16 out of 28 (57.1%) chronic lymphoid leukemia (CLL) cases, 11 out of 28 (39.3%) acute myeloid leukemia (AML) cases, and four out of 22 (18.2%) acute lymphoid leukemia (ALL) cases.ResultsVariable levels of p53 expression were observed in leukemic cells: 12 out of 41 (29.2%) in CML, nine out of 28 (32.1%) in CLL, 15 out of 28 (53.6%) in AML, and eight out of 22 (36.4%) in ALL samples.ConclusionsIn our study, no significant association between p53 expression and MDR functional phenotype was observed in ALL, CLL, and AML. On the other hand, a significant association (P = 0.0003) of the coexpression was observed in CML. The p53 overexpression was more frequently seen in the accelerated phase and the blastic phase of this disease. Our results suggest that an MDR functional phenotype could be associated with p53 mutation in the advanced stage of leukemias. © 2004 Wiley‐Liss, Inc.
Multiplex bead array assays for detection of soluble cytokines: Comparisons of sensitivity and quantitative values among kits from multiple manufacturers
Authors: Khan Sameena S. , Smith Meghan S. , Reda Debra , Suffredini Anthony F. , McCoy J. Philip 
Published: August 2004

AbstractBackgroundMultiplex bead array assays permit simultaneous cytometric quantitation of multiple cytokines in solution by capturing these to spectrally distinct beads. Because several manufacturers offer reagents to quantitate the same cytokines on a single instrument, a comparison should be made to determine whether these kits yield similar data and whether these data are comparable to enzyme‐linked immunosorbent assay (ELISA).MethodsThis study compared cytokine detection kits by using Luminex 100. Twenty‐six serum samples from seven subjects were analyzed for interferon‐γ, interleukins 1β, 6, and 8, and tumor necrosis factor‐α by using multiplex kits from LINCO Research, Bio‐Rad Laboratories, R&D Systems, and BioSource International. Each assay was performed according to the manufacturers' specifications. Standard curves were generated by using reference concentrations supplied by each manufacturer. ELISAs for interleukin‐8 were performed by using kits from R&D and BioSource.ResultsCytokine levels followed similar patterns, although absolute concentrations differed among kits. ELISA and Luminex values for interleukin‐8 were similar in kits from the same manufacturer.ConclusionsBecause relative cytokine measurements are often valuable when performed serially, it may be possible to make interlaboratory comparisons by using different kits. When comparison of absolute values is crucial, kits from the same supplier should be used. Within‐vendor, bead array, and ELISA values appear comparable. Published 2004 Wiley‐Liss, Inc.
Organization and function of microfilaments during late epiboly in zebrafish embryos
Authors: Cheng Jackie C. , Miller Andrew L. , Webb Sarah E. 
Published: August 2004

AbstractWe report that, during epiboly in zebrafish, three F‐actin–based structures appear only after the blastoderm migrates past the embryonic equator. They are composed of two ring‐like F‐actin structures that form at the deep cell and enveloping layer margins of the blastoderm and a punctate actin band that develops in the external yolk syncytial layer. Treatment with cytochalasin B or the calcium chelator dibromo‐BAPTA results in the disruption of all three of these actin‐based structures, leading to the slowing or immediate arrest of epiboly, respectively, followed by a failure of yolk cell occlusion and the eventual lysis of the embryo through the vegetal pole region. We suggest, therefore, that these structures function in the occlusion of the vegetal portion of the yolk cell during the latter stages of epiboly. Possible roles for these new structures, their modulation by Ca2+, as well as the functions of other previously described F‐actin–based structures observed throughout epiboly, are discussed. Developmental Dynamics 231:313–323, 2004.© 2004 Wiley‐Liss, Inc.
d‐ or f‐Mononuclear and Related Heterodinuclear Complexes With [1+1] Asymmetric Compartmental Macrocycles
Authors: Caneschi Andrea , Sorace Lorenzo , Casellato Umberto , Tomasin Patrizia , Vigato Pietro Alessandro 
Published: August 2004

Abstractd‐ or f‐mononuclear and d,f‐heterodinuclear complexes with the [1+1] asymmetric compartmental macrocycles H2LA, H2LB, H2LC or H2LD, derived from the condensation of 1,2‐diaminoethane or 1,3‐diaminopropane with 3,3′‐(3‐oxapentane‐1,5‐diyldioxy)bis(2‐hydroxybenzaldehyde) or 3,3′‐(3,6dioxaoctane‐1,8‐diyldioxy)bis(2‐hydroxybenzaldehyde), have been synthesized and characterized, including by single‐crystal X‐ray structural determinations. The influence of coordinating size and the number of donor atoms of the two adjacent chambers on the preparation of stable d,f‐heterodinuclear complexes has also been tested. The X‐ray structure of the isostructural complexes [MLn(L)(Cl)3(CH3OH)] (MLn = LaCu, LaZn, TbCu) shows the metal(II) ion residing in the N2O2 site in a square‐pyramidal coordination, the fifth apical position being filled by a chloride ion, while each lanthanide(III) ion is located in the O2O4 site and reaches nona‐coordination by linking six oxygen atoms of the macrocyclic ligand, two chloride ions and the oxygen atom of a methanol molecule. Magnetic susceptibility data, complemented by EPR spectroscopy, of the heterodinuclear complexes, studied over the range 2−300 K, show a ferromagnetic coupling for the CuGd complex, whereas, when comparing CeCu and TbCu derivatives with the corresponding Zn derivatives, no appreciable interaction could be detected for the former and a ferromagnetic interaction seems to dominate in the latter. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Two Copper(II) Complexes Built from a Novel Redox‐Active Bipyridinium Dimer Ligand and Oxalate Anions: Synthesis, Crystal Structure and Magnetic Properties
Authors: Sun Yan‐Qiong , Zhang Jie , Chen Jing‐Lin , Yang Guo‐Yu 
Published: August 2004

AbstractThe synthesis of a novel V‐shaped redox‐active bipyridinium dimer ligand, 2,6‐bis(4′‐pyridyl‐1′‐pyridiniumyl)pyrazine (Bpypr) dichloride and its copper complexes, (H2Bpypr)[Cu2(C2O4)4] (1) and {[(Bpypr)Cu2(C2O4)3(H2O)2]·5H2O}n (2), are described. Single‐crystal X‐ray diffraction studies confirm that complex 1 contains one V‐shaped H2Bpypr cation and two essentially planar [Cu(C2O4)2]2− anions, which participate in two hydrogen bonds through the two N−H moieties. Complex 2 has a 1D zigzag chain structure composed of [Cu2(C2O4)3]2− units bridged by V‐shaped Bpypr cations. The magnetic study revealed the occurrence of a weak ferromagnetic interaction within the dinuclear copper unit of complex 2. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Adducts of Aluminum and Gallium Trichloride with a N‐Heterocyclic Carbene and an Adduct of Aluminum Trichloride with a Thione
Authors: Stasch Andreas , Singh Sanjay , Roesky Herbert W. , Noltemeyer Mathias , Schmidt Hans‐Georg 
Published: August 2004

AbstractThe reactions of AlCl3 and GaCl3 with 1,3,4,5‐tetramethylimidazole‐2‐ylidene in toluene at room temperature affords the 1:1 adducts 5 and 6, respectively. The use of a bulky N‐heterocyclic carbene (NHC) in toluene/THF and AlCl3 results in the formation of an imidazolium salt 7 with the tetrachloroaluminate anion. A 1:1 adduct 8 of 1,3,4,5‐tetramethylimidazole‐2(3H)‐thione with AlCl3 is obtained in toluene. The crystal structures of 5·0.5C7H8, 7·THF and 8 were determined. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
18‐Crown‐6 and Titanium Tetrafluoride − Preparation of the TiIV Fluoride Crown Ether Complexes (TiF4)2(18‐Crown‐6) and the Stabilization of cis‐TiF4(H2O)2 in [{cis‐TiF4(H2O)2}2(18‐Crown‐6)]
Authors: Cameron T. Stanley , Decken Andreas , Ilyin Evgeny G. , Nikiforov Grigori B. , Passmore Jack 
Published: August 2004

AbstractReaction of TiF4 and 18‐crown‐6 in MeCN affords the molecular complex [(cis‐TiF4)2(18‐crown‐6)] (1) only. Water and THF displace the 18‐crown‐6 in the tetrafluoro complex 1, with the formation of cis‐TiF4L2. The complex cis‐TiF4(H2O)2 and 18‐crown‐6 form [{cis‐TiF4(H2O)2}2(18‐crown‐6)] (2), in which cis‐TiF4(H2O)2 and 18‐crown‐6 are connected by hydrogen bonding through the protons of coordinated H2O in TiF4(H2O)2 and the oxygen atoms of the crown ether. Complexes 1 and 2 were characterized by X‐ray single crystal analysis, elemental analysis, IR, NMR and Mass spectroscopy. The relative basicities of the 18‐crown‐6 and the molecular donor ligands MeCN, THF, H2O toward TiIV fluoride were established by NMR spectroscopic investigations of the substitution reactions. 18‐crown‐6 is slightly more basic than MeCN, similar to that of Et2O, and less basic than THF and H2O. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Cover Picture: Plasma‐Enhanced CVD Synthesis and Structural Characterization of Ta2N3 (Eur. J. Inorg. Chem. 16/2004)
Authors: Ganin Alexei Yu. , Kienle Lorenz , Vajenine Grigori V. 
Published: August 2004

AbstractThe cover picture shows symbolically the activation of an N2 molecule by igniting a plasma discharge in nitrogen gas. The crystal structure of a new tantalum nitride obtained by the plasma‐enhanced CVD method is seen in the background. Details are discussed in the article by G. V. Vajenine et al. on p. 3233 ff. We thank the Alexander von Humboldt Foundation for support through a Sofia Kovalevskaja Research Award.
Use of Bile Acids in Pharmacological and Supramolecular Applications
Authors: Virtanen Elina , Kolehmainen Erkki 
Published: August 2004

AbstractBile acid‐based structures have become increasingly important in different fields of chemistry over recent years, having found applications in pharmacology, supramolecular chemistry and nanoscience. Some interesting studies concerning these applications are reviewed, together with the latest developments in synthetic and analytical methods for bile acid‐derived frameworks. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Polymer‐Bound Diphenylphosphane Hydrobromide, a Mild Acid for the Activation of Enol Ethers: Applications in Polymer‐Assisted Glycosidations
Authors: Jaunzems Janis , Kashin Dmitri , Schönberger Andreas , Kirschning Andreas 
Published: August 2004

AbstractPolymer‐bound diphenylphosphane hydrobromide 2 shows excellent properties in the activation of enol ethers and glycals, the introduction and cleavage of THP ethers being promoted with excellent yields with this functionalized polymer. Glycosidations of glycals work equally well, with suppression of the formation of undesired Ferrier rearranged products. The reagent is sufficiently mild to leave labile 2‐deoxy glycosidic bonds and acid‐labile protecting groups intact. It can be employed to transfer disaccharide glycosyl donors onto aglycons and is also selective for the promotion of two glycosidations in one pot. Highly hindered glycosyl donor groups such as the hydroxy group at C‐13 of the baccatin III framework can be glycosylated with glycals in the presence of this polymer‐bound reagent. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Synthesis of Novel 5α,9α‐Bridged Steroids by a Boron Trifluoride−Diethyl Ether Induced Rearrangement
Authors: Bondarenko Lidija , Lorenc Ljubinka , Bläser Dieter , Boese Roland 
Published: August 2004

AbstractA stereoselective and synthetically useful rearrangement reaction of 5α,8α‐bridged 9,11α‐epoxy steroids induced by boron trifluoride−diethyl ether is presented, in the preparation of a new class of 5α,9α‐bridged 11α‐hydroxy steroid derivatives in high yields. Lactones were prepared from several of the rearranged 11α‐hydroxy compounds. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Cyclizations of Silyl Enol Ether Radical Cations − The Cause of the Stereoselectivity
Authors: Bunte Jens O. , Heilmann Eike K. , Hein Birka , Mattay Jochen 
Published: August 2004

AbstractWe have used photoinduced electron transfer (PET) activation of silyl enol ethers for the synthesis of tricyclic hydrocarbons. The mechanism of this reaction was investigated by conducting independent radical‐induced cyclizations of corresponding iodo ketones and performing density functional theory (DFT) calculations on the possible intermediates. Our aim was to explain the nature of the reactive intermediate of the cyclization step and to find the causes of the various types of selectivity observed in this process. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Double Cyclization of Bis(α‐hetarylmethyl)amino Esters to Optically Active Bridged N‐Heterocycles of HIV‐Inhibiting Activity
Authors: Faltz Heike , Bender Christoph , Wöhrl Birgitta M. , Vogel‐Bachmayr Karin , Hübscher Ullrich , Ramadan Kristijan , Liebscher Jürgen 
Published: August 2004

AbstractAnellated 1‐azabicyclo[3.3.1]nonanes 6 were synthesized by several routes starting from natural α‐amino esters 2 and o‐haloaryl‐ or o‐bromohetarylmethyl bromides 1. N‐Alkylation of the starting amino esters to 5 and 3 was followed by halogen/lithium exchange and double cyclization. The cyclization products 6 exhibit interesting inhibition of RNase H and DNA‐polymerase activity of reverse transcriptase (RT) of HIV‐1 at concentrations where human cellular DNA polymerases are not affected. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)