bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photosensitized one-electron oxidation of DNA
Authors: Kawai Kiyohiko , Majima Tetsuro 
Published: June 2005

Abstract
Photosensitized one-electron oxidation of DNA has attracted much interest because it causes oxidative damage which leads to mutation, and because it is involved in the basic mechanism of photodynamic therapy. In the present article, we describe the mechanistic study of photosensitized DNA damage, especially addressing the kinetics of hole transfer by adenine(A)-hopping and its effect on the DNA damage. The combination of the transient absorption measurement and DNA damage quantification by high-performance liquid chromatography clearly demonstrate that the yield of the DNA damage correlates well with the lifetime of the charge-separated state caused by A-hopping, showing that hole transfer helps DNA damage. These findings led us to propose a new method to accomplish the efficient DNA damage using a combination of two-color, two-laser irradiation.
Photooxygenation in polymer matrices: En route to highly active antimalarial peroxides
Authors: Griesbeck Axel G. , El-Idreesy Tamer T. , Bartoschek Anna 
Published: June 2005

Abstract
Photooxygenation involving the first excited singlet state of molecular oxygen is a versatile method for the generation of a multitude of oxy-functionalized target molecules often with high regio- and stereoselectivities. The efficiency of singlet-oxygen reactions is largely dependent on the nonradiative deactivation paths, mainly induced by the solvent and the substrate intrinsically. The intrinsic (physical) quenching properties as well as the selectivity-determining factors of the (chemical) quenching can be modified by adjusting the microenvironment of the reactive substrate. Tetraarylporphyrins or protoporphyrin IX were embedded in polystyrene (PS) beads and in polymer films or covalently linked into PS during emulsion polymerization. These polymer matrices are suitable for a broad variety of (solvent-free) photooxygenation reactions. One specific example discussed in detail is the ene reaction of singlet oxygen with chiral allylic alcohols yielding unsaturated β-hydroperoxy alcohols in (threo) diastereoselectivities, which depended on the polarity and hydrogen-bonding capacity of the polymer matrix. These products were applied for the synthesis of mono- and spirobicyclic 1,2,4-trioxanes, molecules that showed moderate to high antimalarial properties. Subsequent structure optimization resulted in in vitro activities that surpassed that of the naturally occurring sesquiterpene-peroxide artemisinin.
Genome-Wide Characterization of Tetrahymena thermophila Chromosome Breakage Sites. I. Cloning and Identification of Functional SitesSequence data from this article have been deposited with the EMBL/GenBank Data Libraries under accession nos. AY653004, AY653005, AY653006, AY653007, AY653008, AY653009, AY653010, AY653011, AY653012, AY653013, AY653014, AY653015, AY653016, AY653017, AY653018, AY653019, AY653020, AY653021, AY653022, AY653023, AY653024, AY653025, AY653026, AY653027, AY653028, AY653029.
Authors: Hamilton Eileen , Bruns Peter , Lin Cindy , Merriam Virginia , Orias Eduardo , Vong Linh , Cassidy-Hanley Donna 
Published: June 2005

Abstract
The chromosomes of the macronuclear (expressed) genome of Tetrahymena thermophila are generated by developmental fragmentation of the five micronuclear (germline) chromosomes. This fragmentation is site specific and directed by a conserved 15-bp chromosome breakage sequence (Cbs element). This article reports the construction of a library enriched for chromosome breakage junctions and the development of a successful scheme for the genome-wide isolation and characterization of functional Cbs junctions. Twenty-three new Cbs junctions were characterized and each was assigned to a specific micronuclear chromosome or chromosome arm. Two distinct previously unreported variant chromosome breakage sequences were found, each in two or more functional Cbs elements. Analysis of natural Cbs junctions confirmed that microheterogeneity in the macronuclear telomere addition site is associated with chromosome fragmentation. The physical and genetic characterization of these functional chromosome breakage junctions is reported in the accompanying article in this issue. The whole-genome shotgun sequencing and auto-assembly phase of the Tetrahymena Genome Initiative has recently been completed at The Institute for Genome Research (TIGR). By providing unique sequence from the natural ends of macronuclear chromosomes, Cbs junctions characterized in the work reported here will serve as useful sequence tags for relating macro- and micronuclear genetic, physical, and sequence maps.
The Dominant Inhibitory Chalcone Synthase Allele C2-Idf (Inhibitor diffuse) From Zea mays (L.) Acts via an Endogenous RNA Silencing MechanismSequence data from this article have been deposited with the EMBL/GenBank Data Libraries under accession nos. AY728478 [c2 gene chalcone synthase (wild type) C2-W22], AY728476 (Zea mays L. C2-Idf allele; gene copies C2-Idf-I and C2-Idf-II), and AY728477 (Zea mays L. C2-Idf allele; gene copy C2-Idf-III).
Authors: Della Vedova Chris B , Lorbiecke René , Kirsch Helene , Schulte Michael B , Scheets Kay , Borchert Lutz M , Scheffler Brian E , Wienand Udo , Cone Karen C , Birchler James A 
Published: June 2005

Abstract
The flavonoid pigment pathway in plants has been used as a model system for studying gene regulatory mechanisms. C2-Idf is a stable dominant mutation of the chalcone synthase gene, c2, which encodes the first dedicated enzyme in this biosynthetic pathway of maize. Homozygous C2-Idf plants show no pigmentation. This allele also inhibits expression of functional C2 alleles in heterozygotes, producing a less pigmented condition instead of the normal deeply pigmented phenotype. To explore the nature of this effect, the C2-Idf allele was cloned. The gene structure of the C2-Idf haplotype differs substantially from that of the normal c2 gene in that three copies are present. Two of these are located in close proximity to each other in a head-to-head orientation and the third is closely linked. Previous experiments showed that the lower level of pigmentation in heterozygotes is correlated with reduced enzyme activity and low steady-state mRNA levels. We found that c2 transcription occurs in nuclei of C2-Idf/C2 heterozygotes, but mRNA does not accumulate, suggesting that the inhibition is mediated by RNA silencing. Infection of C2-Idf/C2 heterozygotes with viruses that carry suppressors of RNA silencing relieved the phenotypic inhibition, restoring pigment production and mRNA levels. Finally, we detected small interfering RNAs (siRNAs) in plants carrying C2-Idf, but not in plants homozygous for the wild-type C2 allele. Together, our results indicate that the inhibitory effect of C2-Idf occurs through RNA silencing.
Tetracycline Fibers as an Adjunct in the Treatment of Nifedipine‐Induced Gingival Enlargement
Authors: Sakellari Dimitra , Vouros Ioannis D. , Aristodemou Elena , Konstantinidis Antonis B. , Socransky Sigmund , Goodson Max 
Published: June 2005

Background: The hypothesis that nifedipine‐induced gingival enlargement in periodontitis patients can be treated with the adjunctive use of tetracycline (TCN) fibers was tested in this study.Methods: Ten patients (mean age 66 ± 4 years) with chronic periodontitis combined with nifedipine‐induced gingival enlargement participated. Full mouth recordings of clinical parameters (probing depth, clinical attachment level, bleeding on probing, presence or absence of plaque) were assessed at baseline and gingival enlargement was estimated from casts. Participants were instructed in proper oral hygiene and received supragingival scaling before being reassessed 1 month later. They subsequently received full‐mouth scaling and root planing followed by the immediate placement of TCN fibers in all pockets >5 mm. Clinical parameters were reassessed at 3, 6, and 12 months after completion of treatment.Results: TCN fiber placement was well tolerated by patients. All clinical parameters recorded displayed significant improvements after treatment, and they were preserved for the 12‐month experimental period. A significant reduction of the percentage of pockets >5 mm was noticed after treatment. The reduction of enlargement was still observed at 12 months despite patients not achieving optimal oral hygiene.Conclusion: Placement of tetracycline fibers as an adjunct to mechanical treatment is an option for the non‐invasive therapy of nifedipine‐induced gingival enlargement in periodontitis patients whose general medical condition and concomitant ailments do not favor a surgical approach. J Periodontol 2005;76:1034‐1039.
Pathologic Tooth Migration
Authors: Brunsvold Michael A. 
Published: June 2005

Pathologic tooth migration (PTM) is a common complication of moderate to severe periodontitis and is often the motivation for patients to seek periodontal therapy. In this review of the literature, available information concerning prevalence, etiology, treatment, and prevention of pathologic tooth migration is summarized.Prevalence of PTM among periodontal patients has been reported to range from 30.03% to 55.8%. A survey of the literature regarding chief complaints of periodontal patients support these high prevalence findings. The etiology of PTM appears to be multifactorial. Periodontal bone loss appears to be a major factor in the etiology of PTM. Many aspects of occlusion can contribute to abnormal migration of teeth, and more than one of those factors may be present in an individual patient. Soft tissue forces of the tongue, cheeks, and lips are known to cause tooth movement and in some situations can cause PTM. Also considered important in the etiology of PTM is pressure produced from inflammatory tissues within periodontal pockets. Because extrusion is a common form of PTM, clinical observations support the theory that eruption forces sometimes play a role in the etiology of PTM. Many oral habits have been associated with PTM which are often difficult for the therapist to detect.Most cases of severe PTM require a team approach to achieve success. Periodontal, orthodontic, and prosthodontic treatment are often required. Many patient variables enter into the selection of treatment for PTM. In early stages of PTM, spontaneous correction of migrated teeth sometimes occurs after periodontal therapy. Light intrusive forces are used successfully to treat extrusion and flaring forms of PTM.Based on the literature reviewed, it appears that many cases of PTM could be prevented through the early diagnosis and treatment of periodontal disease, occlusal contributing factors, gingival enlargement, and oral habits. J Periodontol 2005;76:859‐866.
Echelles de temps et d'espace du controle tectonique d'un bassin flexural intracratonique; le bassin de Paris
Authors: Robin Cecile , Guillocheau Francois , Allemand Pascal , Bourquin Sylvie , Dromart Gilles , Gaulier Jean-Michel , Prijac Christophe 
Published: June 2005

Abstract
The Meso-Cenozoic intracratonic flexural Paris Basin is a good tool to determinate the time/space-scales of the tectonic control on the sedimentary record. This study is based on basin-scale 2D sedimentary geometries of the different orders of stratigraphic cycles and on 1D/3D accommodation space measurements (space available for sediments created by subsidence and/or eustatism). Tectonic controls occur at least at three different time-scales: 230 m.y. (basin evolution), 10-40 m.y. (major stratigraphic cycles) and 1-5 m.y. (minor stratigraphic cycles). The evolution of the flexural intracratonic Paris basin can be described as the result of a long term thermal subsidence component with superimpositions of short-term tectonic components, due to intraplate deformations of 10-40 Ma and 1-5 Ma frequencies.
What was the late Pliocene Mediterranean climate like; a preliminary quantification from vegetation
Authors: Combourieu-Nebout Nathalie , Fauquette Severine , Quezel Pierre 
Published: June 2005

Abstract
Reconstruction of the composition and organisation of the late Pliocene vegetation in central Mediterranean and quantification of the climatic requirements of its main representatives allow temperature and precipitation estimates during the late Pliocene glacial/interglacial cycles, at ca 2.4 Ma. The late Pliocene climatic glacial and interglacial conditions are illustrated on a bioclimagram which correlates the mean annual temperature and precipitation criteria. Comparison between modern and late Pliocene vegetation indicates that late Pliocene interglacial climate was approximately 4 degrees C warmer, with more higher amount of precipitation than today, and that conditions similar to modern ones prevailed during late Pliocene glacials.
La tectonique cisaillante polyphasee du Sud Limousin (Massif central francais) et son interpretation dans un modele d'evolution polycyclique de la chaine hercynienne
Authors: Roig Jean-Yves , Faure Michel 
Published: June 2005

Abstract
Structural, kinematics and thermo-barometric analyses of the ductile deformation of the south-Limousin metamorphic formations show a polyphase shear tectonics corresponding to two different thrusting events. The older one, is a to the top-to-the-SW thrusting during middle Devonian. This deformation occurs under minimum PT conditions of 7 Kbar/700 degrees C simultaneously to anatexis. The second event is a top-to-the-NW shearing which occurred in late Devonian-early Carboniferous under Barrovian conditions (5 kbar/600 degrees C). Diorites bodies and non-eclogitized mafic rocks allow us to argue for an extensional phase between the two thrusting events. These two ductile and syn-metamorphic deformations take place in a polycyclic evolution model of the Hercynian belt of the French Massif Central.
Analyse quantitative de fracturation des calcaires ypresiens en Tunisie; l'exemple de jebel Ousselat
Authors: Boukadi Noureddine , El Ayeb Sadok , Kharbachi Samir 
Published: June 2005

Abstract
Field studies performed on the well developed fracture system affecting the Ypresian carbonate series of the nummulitic El Gueria Formation and the Globigerinae Bou Dabbous Formation (Jebel Ousselat; Central Tunisia), has led to a better understanding of the effect of fracture systems on the general petrophysical parametres (porosity and permeability) of these two proven petroleum reservoir systems. In this study, we were able to assess a comprehensive quantitative method integrating many parametres such as: major and minor fault trending systems, fracture density and frequency of each fracture system. Results obtained from applying this methodology attest that fracture system analysis should be necessarily integrated in the general approach for estimating reservoir qualities of similar deposits in Tunisia.
Le Trias a caractere extrusif de la zone des domes; example de la structure de Debadib-Ben Gasseur (Tunisie septentrionale)
Authors: Hatira Nouri , Smati Amor , Mansouri Abdelbaki , Perthuisot Vincent , Rouvier Henri 
Published: June 2005

Abstract
The Debadib-Ben Gasseur anticlinal structure, situated between El Kef and the Algero-Tunisian border, belongs to one of the main diapiric, alignments of the oriental Maghreb. It constitutes an elliptic form oriented NE-SW. The heart is occupied by Triassic residual evaporites containing basaltic volcanites which seem to indicate an extensional setting during the Triassic period. The contact between the saliferous bodies and surrounding Cretaceous-Tertiary age rocks is locally underlined by conglomerates including reworked Triassic blocks and glauconite, suggesting a sedimentary contact. Biostratigraphic and sub-surface data could indicate, in terms of model reconstitution, an extrusive system with numerous phases starting in the Aptian and acting until the Tertiary period. However, tectonic events are clearly expressed during the Miocene.
Late Paleocene event chronology; unconformities, not diachrony
Authors: Aubry Marie-Pierre , Cramer Benjamin S. , Miller Kenneth G. , Wright James D. , Kent Dennis V. , Olsson Richard K. 
Published: June 2005

Abstract
The chronology of the events associated with the late Paleocene thermal maximum (LPTM, Chron C24r) has been established through the construction of a composite reference section that involved chemomagnetobiostratigraphic correlations and assumed minimum diachrony of biostratigraphic events. On this basis, discrepancies between correlations in different sections were explained by inferred unconformities. However, diachrony between distant sections cannot be ruled out. We report here on two geographically close sections drilled onshore New Jersey that yield different records of chemomagnetobiostratigraphic correlations in the interval representing Chron C24r. Because of their proximity ( approximately 40 km apart), diachrony of biostratigraphic events between the two sections can be ruled out. In contrast, the marked lithologic disconformities in the sections explain well the different records of events. We thus conclude that the current relative chronology for Chron C24r is firmly based and that the upper Paleocene-lower Eocene stratigraphic record yields multiple unconformities, with Subzone NP9b rarely sampled. We examine the implications that undeciphered unconformities may have on the identification of proxies for paleoceanographic reconstruction, in particular with regard to the identification of the carbon isotope excursion (CIE) that reflects a dramatic latest Paleocene disturbance of the carbon cycle. We propose biostratigraphic means (short-lived calcareous nannoplankton and planktonic foraminifera taxa) that permit the unequivocal identification of the CIE not only in the oceanic realm but also in neritic settings.
Effets de la texture petrographique sur les proprietes petrophysiques d'un calcaire en zone de diagenese meteorique (calcaire oligocene d'Aquitaine, France)
Authors: Cerepi Adrian , Humbert Louis , Burlot Rene 
Published: June 2005

Abstract
120 samples of three quarries of the Oligocene Aquitaine limestone were subjected to petrographic, petrophysical and chemical analyses. Strong variations of depositional and diagenetic textures were observed. Four main depositional textures characterize this limestone: mudstone-wackestone, packstone, packstone-grainstone and grainstone. The diagenetic transformations recognized and specially meteoric leaching increases the heterogeneity of porous medium. The "Pierre de Bordeaux" shows a high variation of porosity (12,8 % to 42,51%), permeability (4,27 to 4755 mD), specific surface (0,78 to 3,73 m 2 /g) and distribution of pore throats (from monomodal to three modal distribution). Petrophysical properties depend strongly on depositional and diagenetic patterns. Textures with two and three modal distribution of porous medium, packstone-grainstone and grainstone have the best reservoir properties. The meteoric dissolution associated to microfracturing improves strongly both the macroporosity, permeability in mudstone-wackestone and packstone and increases the pore space complexity in all textures.
Tectonique synsedimentaire d'age cretace superieur en Tunisie nord orientale; blocs bascules et reorganisation des aires de subsidence
Authors: Boutib Lahcen , Melki Fetheddine , Zargouni Fouad 
Published: June 2005

Abstract
Structural analysis of late Cretaceous sequences from the northeastern Tunisian Atlas, led to conclude on an active basin floor instability. Regional tectonics resulted in tilted blocks with a subsidence reorganization, since the Campanian time. These structural movements are controlled both by N140 and N100-120 trending faults. The Turonian-Coniacian and Santonian sequences display lateral thickness and facies variation, due to tectonic activity at that time. During Campanian-Maastrichtian, a reorganization of the main subsidence areas occurred, the early Senonian basins, have been sealed and closed and new half graben basins developed on area which constituted previously palaeohigh structures. These syndepositional deformations are characterized by frequent slumps, synsedimentary tilting materials, sealed normal faults and progressive low angle unconformities. These tilted blocks combined to a subsidence axis migration were induced by a NE-SW trending extensional regime. This extension which affects the Tunisian margin during the Upper Cretaceous, is related to the Tethyan and Mesogean rifting phase which resulted from the combined movements of the African and European plates.
Saisonnalite et effets de seuils de la sedimentation organique detritique en milieu lacustre; heterochronie de l'enregistrement organique et des fluctuations climatiques (bassin de Chaillexon, Doubs, France)
Authors: Di Giovanni Christian , Disnar Jean-Robert , Bichet Vincent , Campy Michael 
Published: June 2005

Abstract
Optical analysis (palynofacies) of the organic matter (OM), occurring in various compartments (soils, bedrock formations, lacustrine chalks) of the lacustrine basin of Chaillexon (Doubs, France) has led to the definition of organic markers. Their variable contributions were observed in suspended matters taken over a period of a year (annual scale) and in lacustrine sediments covering the last 12,000 years B.P. (millennial scale). Results obtained lead to three main conclusions. Firstly, there exists a seasonal variation in the detrital organic fluxes, directly linked to the autumnal litter production. This allows us to distinct the detrital OM loaded during autumn-winter organic floods and spring-summer ones. Secondly, the organic record in Boreal to modern sediments of the lake of Chaillexon, fed by autumn-winter fluxes, appears mainly controlled by the autumnal productivity of vegetal biomass. Thirdly, the organic record does not point out a progressive evolution of organic fluxes linked with successive climatic phases. It shows abrupt ruptures of the balance (threshold effects) corresponding with the passage of the tree line in the watershed. These ruptures are not necessarily synchronous with climatic fluctuations.
Effects of petroleum emplacement on cementation in carbonate reservoirs
Authors: Worden Richard H. , Heasley Emma C. 
Published: June 2005

Abstract
Carbonate diagenesis can theoretically either be enhanced or retarded by petroleum emplacement depending on: the oil-water wettability of the rocks, the CO 2 -content of the migrated petroleum, and the presence of oxidised sulphur or iron compounds in the rocks. A detailed case study of Jurassic oolites from a UK oil field showed first that petroleum emplacement retarded diagenesis in the oil leg and thus helped preserve permeability, but second showed that entrained CO 2 caused cementation and pore-system modification in the water leg.
Recalage biostratigraphique et nouvelle datation de surfaces d'emersion du Kimmeridgien-Tithonien dans le Jura meridional et consequences sur leur interpretation sequentielle
Authors: Enay Raymond 
Published: June 2005

Abstract
In various recent studies the area of Saint-Germain-de-Joux (Ain Department, France) has been used as a reference to define a new major sequence boundary that was added to the Exxon cycle chart and assigned to the Kimmeridgian-Tithonian boundary. Within the reef complex of Saint-Germain-de-Joux the new sequence boundary SB 140 is believed to be represented by the horizon overlain by a black-pebble conglomerate. A comprehensive survey of the biostratigraphical data already published proves the age of the discontinuity to be in fact late Kimmeridgian, Beckeri Zone. Following recent refinement of the vertical range of the species of the genus Gravesia, the Kimmeridgian-Tithonian boundary is now placed within the Gravesia beds in the lower part of the bioturbated limestone ("Calcaires a tubulures") of the Couches du Chailley Fm.