bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitative estimation of Nipah virus replication kinetics in vitro
Authors: Chang Li-Yen , Mohd Ali AR , Hassan Sharifah Syed , AbuBakar Sazaly 
Published: June 2006

Abstract

Background
Nipah virus is a zoonotic virus isolated from an outbreak in Malaysia in 1998. The virus causes infections in humans, pigs, and several other domestic animals. It has also been isolated from fruit bats. The pathogenesis of Nipah virus infection is still not well described. In the present study, Nipah virus replication kinetics were estimated from infection of African green monkey kidney cells (Vero) using the one-step SYBR® Green I-based quantitative real-time reverse transcriptase-polymerase chain reaction (qRT-PCR) assay.

Results
The qRT-PCR had a dynamic range of at least seven orders of magnitude and can detect Nipah virus from as low as one PFU/μL. Following initiation of infection, it was estimated that Nipah virus RNA doubles at every ~40 minutes and attained peak intracellular virus RNA level of ~8.4 log PFU/μL at about 32 hours post-infection (PI). Significant extracellular Nipah virus RNA release occurred only after 8 hours PI and the level peaked at ~7.9 log PFU/μL at 64 hours PI. The estimated rate of Nipah virus RNA released into the cell culture medium was ~0.07 log PFU/μL per hour and less than 10% of the released Nipah virus RNA was infectious.

Conclusion
The SYBR® Green I-based qRT-PCR assay enabled quantitative assessment of Nipah virus RNA synthesis in Vero cells. A low rate of Nipah virus extracellular RNA release and low infectious virus yield together with extensive syncytial formation during the infection support a cell-to-cell spread mechanism for Nipah virus infection.
Members of the Hyposoter didymator Ichnovirus repeat element gene family are differentially expressed in Spodoptera frugiperda
Authors: Galibert L , Devauchelle G , Cousserans F , Rocher J , Cérutti P , Barat-Houari M , Fournier P , Volkoff AN 
Published: June 2006

Abstract

Background
The abundance and the conservation of the repeated element (rep) genes in Ichnoviruses genomes suggest that this gene family plays an important role in viral cycles. In the Ichnovirus associated with the wasp Hyposoter didymator, named HdIV, 10 rep genes were identified to date. In this work, we report a relative quantitative transcription study of these HdIV rep genes in several tissues of the lepidopteran host Spodoptera frugiperda as well as in the H. didymator wasps.

Results
The data obtained in this work indicate that, in the early phases of infection (24 hours), HdIV rep genes each display different levels of transcripts in parasitized 2nd instar or HdIV-injected last instar S. frugiperda larvae. Only one, rep1, is significantly transcribed in female wasps. Transcript levels of the HdIV rep genes were found as not correlated to their copy number in HdIV genome. Our results also show that HdIV rep genes display different tissue specificity, and that they are primarily transcribed in S. frugiperda fat body and cuticular epithelium.

Conclusion
This work is the first quantitative analysis of transcription of the ichnovirus rep gene family, and the first investigation on a correlation between transcript levels and gene copy numbers in Ichnoviruses. Our data indicate that, despite similar gene copy numbers, not all the members of this gene family are significantly transcribed 24 hours after infection in lepidopteran larvae. Additionally, our data show that, as opposed to other described HdIV genes, rep genes are little transcribed in hemocytes, thus suggesting that they are not directly associated with the disruption of the immune response but rather involved in other physiological alterations of the infected lepidopteran larva.
Genetic Variations in Radiation and Chemotherapy Drug Action Pathways Predict Clinical Outcomes in Esophageal Cancer
Authors: Wu Xifeng , Gu Jian , Wu Tsung-Teh , Swisher Stephen G. , Liao Zhongxin , Correa Arlene M. , Liu Jun , Etzel Carol J. , Amos Christopher I. , Huang Maosheng , Chiang Silvia S. , Milas Luke , Hittelman Walter N. , Ajani Jaffer A. 
Published: June 2006

PurposeUnderstanding how specific genetic variants modify drug action pathways may provide informative blueprints for individualized chemotherapy.MethodsWe applied a pathway-based approach to examine the impact of a comprehensive panel of genetic polymorphisms on clinical outcomes in 210 esophageal cancer patients.ResultsIn the Cox proportional hazards model, MTHFR Glu429Ala variant genotypes were associated with significantly improved survival (hazard ratio [HR] = 0.56; 95% CI, 0.35 to 0.89) in patients treated with fluorouracil (FU). The 3-year survival rates for patients with the variant genotypes and the wild genotypes were 65.26% and 46.43%, respectively. Joint analysis of five polymorphisms in three FU pathway genes showed a significant trend for reduced recurrence risk and longer recurrence-free survival as the number of adverse alleles decreased (P = .004). For patients receiving platinum drugs, the MDR1 C3435T variant allele was associated with significantly reduced recurrence risk (HR = 0.25; 95% CI, 0.10 to 0.64) and improved survival (HR = 0.44; 95% CI, 0.23 to 0.85). In nucleotide excision repair genes, there was a significant trend for a decreasing risk of death with a decreasing number of high-risk alleles (P for trend = .0008). In base excision repair genes, the variant alleles of XRCC1 Arg399Gln were significantly associated with the absence of pathologic complete response (odds ratio = 2.75; 95% CI, 1.14 to 6.12) and poor survival (HR = 1.92; 95% CI, 1.00 to 3.72).ConclusionSeveral biologically plausible associations between individual single nucleotide polymorphisms and clinical outcomes were found. Our data also strongly suggest that combined pathway-based analysis may provide valuable prognostic markers of clinical outcomes.
The role of adrenergic stimulation in maintaining maximum cardiac performance in rainbow trout (Oncorhynchus mykiss) during hypoxia,hyperkalemia and acidosis at 10°C
Authors: Hanson Linda M. , Obradovich Shannon , Mouniargi Janet , Farrell Anthony P. 
Published: June 2006

SUMMARYAs rainbow trout approach exhaustion during prolonged exercise, they maintain maximum cardiac output despite the fact their venous blood, which bathes the heart, becomes hypoxic, acidotic and hyperkalemic. Because these factors are individually recognized to have detrimental inotropic and chronotropic effects on cardiac performance, we hypothesized that adrenergic stimulation is critical in maintaining maximum cardiac performance under these collectively adverse conditions in vivo. To test this hypothesis,maximum cardiac performance in the presence and absence of maximal adrenergic stimulation was assessed with in situ rainbow trout hearts using relevant hyperkalemic (5.0 mmol l–1 K+), acidotic(pH 7.5) and hypoxic challenges. With tonic adrenergic stimulation (5.0 nmol l–1 adrenaline), hearts produced only 44.8±14.6% of their normal maximum cardiac output when exposed under normoxic conditions (20 kPa) to the hyperkalemic, acidotic perfusate, indicating that in vivothere was no refuge from cardiac impairment even if venous blood was fully oxygenated. By contrast, maximum adrenergic stimulation (500 nmol l–1 adrenaline), fully protected maximum cardiac performance under hyperkalemic and acidotic conditions over a wide range of oxygen availability, from normoxia to 2.0 kPa, a venous oxygen tension close to routine values in vivo. Extending the level of hypoxia to 1.3 kPa resulted in a 43.6±2.8% decrease in maximum cardiac output, with hearts failing when tested at 1.0 kPa. Our results suggest that adrenergic stimulation of the trout heart is critical in maintaining maximum performance during prolonged swimming tests, and probably during all forms of exhaustive activity and recovery, when venous blood is hyperkalemic, acidotic and hypoxic.
Hot limpets: predicting body temperature in a conductance-mediated thermal system
Authors: Denny Mark W. , Harley Christopher D. G. 
Published: June 2006

SUMMARYLiving at the interface between the marine and terrestrial environments,intertidal organisms may serve as a bellwether for environmental change and a test of our ability to predict its biological consequences. However, current models do not allow us to predict the body temperature of intertidal organisms whose heat budgets are strongly affected by conduction to and from the substratum. Here, we propose a simple heat-budget model of one such animal,the limpet Lottia gigantea, and test the model against measurements made in the field. Working solely from easily measured physical and meteorological inputs, the model predicts the daily maximal body temperatures of live limpets within a fraction of a degree, suggesting that it may be a useful tool for exploring the thermal biology of limpets and for predicting effects of climate change. The model can easily be adapted to predict the temperatures of chitons, acorn barnacles, keyhole limpets, and encrusting animals and plants.
Thermal stress on intertidal limpets: long-term hindcasts and lethal limits
Authors: Denny Mark W. , Miller Luke P. , Harley Christopher D. G. 
Published: June 2006

SUMMARYWhen coupled with long-term meteorological records, a heat-budget model for the limpet, Lottia gigantea, provides a wealth of information regarding environmental and topographic controls of body temperature in this ecologically important species. (1) The maximum body temperature predicted for any site (37.5°C) is insufficient to kill all limpets, suggesting that acute thermal stress does not set an absolute upper limit to the elevation of L. gigantea on the shore. Therefore, the upper limit must be set by behavioral responses, sublethal effects or ecological interactions. (2)Temperatures sufficient to kill limpets are reached at only a small fraction of substratum orientations and elevations and on only three occasions in 5 years. These rare predicted lethal temperatures could easily be missed in field measurements, thereby influencing the interpretation of thermal stress.(3) Body temperature is typically higher than air temperature, but maximum air temperature can nonetheless be used as an accurate predictor of maximum body temperature. Warmer air temperatures in the future may thus cause increased mortality in this intertidal species. Interpretation of the ecological effects of elevated body temperature depends strongly on laboratory measurements of thermal stress, highlighting the need for additional research on the temporal and spatial variability of thermal limits and sublethal stress. The lengthy time series of body temperatures calculated from the heat-budget model provides insight into how these physiological measurements should be conducted.
Silken toolkits: biomechanics of silk fibers spun by the orb web spiderArgiope argentata(Fabricius 1775)
Authors: Blackledge Todd A. , Hayashi Cheryl Y. 
Published: June 2006

SUMMARYOrb-weaving spiders spin five fibrous silks from differentiated glands that contain unique sets of proteins. Despite diverse ecological functions, the mechanical properties of most of these silks are not well characterized. Here,we quantify the mechanical performance of this toolkit of silks for the silver garden spider Argiope argentata. Four silks exhibit viscoelastic behaviour typical of polymers, but differ statistically from each other by up to 250% in performance, giving each silk a distinctive suite of material properties. Major ampullate silk is 50% stronger than other fibers, but also less extensible. Aciniform silk is almost twice as tough as other silks because of high strength and extensibility. Capture spiral silk, coated with aqueous glue, is an order of magnitude stretchier than other silks. Dynamic mechanical properties are qualitatively similar, but quantitatively vary by up to 300% among silks. Storage moduli are initially nearly constant and increase after fiber yield, whereas loss tangents reach maxima of 0.1–0.2 at the yield. The remarkable mechanical diversity of Argiope argentata silks probably results in part from the different molecular structures of fibers and can be related to the specific ecological role of each silk. Our study indicates substantial potential to customize the mechanics of bioengineered silks.
Functional evidence for the presence of a carbonic anhydrase repressor in the eyestalk of the euryhaline green crabCarcinus maenas
Authors: Henry Raymond P. 
Published: June 2006

SUMMARYCarbonic anhydrase (CA) activity and relative expression of CA mRNA were measured in the gills of the euryhaline green crab Carcinus maenas in response to eyestalk ablation (ESA), injection of eyestalk extract and exposure to low salinity. For crabs acclimated to 32 p.p.t. salinity, ESA alone resulted in an increase in both CA activity and relative mRNA expression in the posterior, ion-transporting gills, but not in the anterior, respiratory gills. The ESA-stimulated increase in CA activity was abolished by injections of extracts of eyestalks taken from crabs acclimated to 32 p.p.t. salinity. Transfer of intact crabs from 32 to 10 p.p.t. salinity for 7 days resulted in an eightfold increase in CA activity and a sixfold increase in mRNA expression in posterior gills. ESA potentiated the normal low salinity-mediated CA induction by 23%. Daily injections of eyestalk extract reduced low salinity-stimulated CA induction by nearly 50% in intact crabs and by almost 75% in eyestalk ablated crabs. A 4-day transfer to 10 p.p.t. salinity also caused significant increases in both CA activity and mRNA expression in posterior gills, and ESA resulted in a 32% increase in the normal degree of CA induction. Daily injections of eyestalk extracts reduced CA induction in a dose-dependent manner over the 4-day time course. When CA induction was reduced by 66%, hemolymph osmotic regulation was also disrupted. These results are functional evidence for the presence of a CA repressor in the major endocrine complex of the crab, the eyestalk. This compound appears to function in keeping CA expression at low, baseline levels in crabs at high salinity. Exposure to low salinity removes the effects of the putative repressor,allowing CA expression, and thus CA activity, to increase.
Hydrolysis Kinetics of trans(O)-Bromo, Chloro or Nitro-(3,6,9-Triazaundecanedioato)cobalt(III) Complex
Authors: Kitamura Yoichi , Muneta Hiroyuki , Watanabe Kiyokatsu 
Published: June 2006

Abstract
For the acid-uncatalyzed aquation of trans(O)-[Co(taud)X] at the ionic strength (μ) of 0.1 (NaClO4), the first order rate constant (kaq) is 9.6 × 10−5 s−1 at 25 °C, ΔH‡ = 93 kJ mol−1, ΔS‡ = −10 J K−1 mol−1, ΔV‡ = −3.2 cm3 mol−1 with X = Cl−; and kaq is 4.6 × 10−4s−1 at 25 °C, ΔH‡ = 91 kJ mol−1, ΔS‡ = −4 J K−1 mol−1, ΔV‡ = −2.3 cm3 mol−1 with X = Br−. Here taud stands for the quinquedentate −OOCCH2NH(CH2)2NH(CH2)2NHCH2COO−. These magnitudes of ΔV‡ are slightly different from the expected values. For the acid-catalyzed aquation of trans-(O)-[Co(taud)NO2], kaq/s−1 depends on the [H+]/M of the solution: kaq = 1.3 × 10−4[H+] + 3.09 × 10−3[H+]2 at 45.6 °C and μ = 0.5 (M = mol dm−3). For the base hydrolysis of trans(O)-[Co(taud)X] at μ = 1.0 (NaClO4), the second order rate constant (k2) is 104 M−1 s−1 at 25 °C, ΔH‡ = 77 kJ mol−1, ΔS‡ = 12 J K−1 mol−1 with X = Cl−; and k2 is 760 M−1 s−1 at 25 °C, ΔH‡ = 79 kJ mol−1, ΔS‡ = 36 J K−1 mol−1 with X = Br−. The ΔV‡ ’s at μ ≈ 0 are 19.1 cm3 mol−1 with X = Cl− and 19.7 cm3 mol−1 with X = Br−. In the base hydrolysis with excess NaOH at μ = 1.0, the pseudo-first-order rate constant (kobsd) departs slightly positively from the proportionality to the [OH−] at 0.3 M &lt; [OH−]. This type of nonlinearity has rarely been reported for the base hydrolysis of a cobalt(III) complex. The magnitudes of the activation volume for the base hydrolysis are in line with the SN1 CB mechanism. Therefore, the mechanism may be the SN1 CB mechanism, where an additional minor pathway via the second deprotonation from the taud ligand or via a hydroxide adduct formation to the carbonyl group of the taud ligand also participates.
Preparation of (Alkaneimidoyl)lanthanides and Their Reactions with Carbonyl Compounds
Authors: Murakami Masahiro , Ito Hajime , Ito Yoshihiko 
Published: June 2006

Abstract
The preparation of (alkaneimidoyl)lanthanide(III) reagents and their reactions with carbonyl compounds were studied. Alkyllithium was added to a mixture of an anhydrous lanthanide salt and 2,6-xylyl isocyanide in tetrahydrofuran at −78 °C. Among a series of lanthanide salts, CeCl3 effected the quantitative conversion of the isocyanide to afford an orange solution of (alkaneimidoyl)cerium(III). Although LaCl3, SmI3, and Sm(OTf)3 were found to be highly reactive, multiple insertion of the isocyanide ensued. (Alkaneimidoyl)cerium(III) could also be prepared by the reaction of dialkylmagnesium with CeCl3 and 2,6-xylyl isocyanide at −45 °C. The thus-prepared (alkaneimidoyl)cerium(III) reacted with a carbonyl compound to afford an addition product, i.e., an α-hydroxy imine. The present reactions for the preparation of (alkaneimidoyl)cerium(III) provide a convenient synthetic equivalent to a nucleophilic acyllanthanide species with a wide variation for the acyl group.
Interfacial Adsorption and Ion-Association Extraction of Protonated Tetraphenylporphyrin and Octaethylporphyrin
Authors: Chida Yoshito , Watarai Hitoshi 
Published: June 2006

Abstract
Protonation of tetraphenylporphyrin (TPP) and octaethylporphyrin (OEP) in toluene/acid systems was investigated by a high-speed stirring method. In toluene/sulfuric acid system, the adsorption of the diprotonated TPP and the monoprotonated OEP at the liquid–liquid interface was found, while in other acid systems including hydrochloric acid, perchloric acid, and trichloroacetic acid, the ion-association extraction of H2TPP2+ and HOEP+ was observed as well, depending on the nature of the counter anions and the concentration of the acids. An inverted correlation was suggested between the adsorption constants of the protonated porphyrins and the extraction constants of the acids with the porphyrins.
Intercalation of Water in a Layered Perovskite Compound, NaEuTiO4
Authors: Toda Kenji , Kameo Yutaka , Kurita Satoru , Sato Mineo 
Published: June 2006

Abstract
Intercalation of water was observed in a layered perovskite compound, NaEuTiO4, leading to its hydrated derivatives. There are some metastable intermediates in the hydrated derivatives. The hydration process includes several steps that are topotactic. The crystal structure of the hydrated derivatives was identified by Rietveld analysis for the powder X-ray diffraction pattern. It is confirmed that the water molecules are inserted into the sodium layer of NaEuTiO4.
Isolation and Spectroscopic Properties of A-β-[PV3W9O40]6− Anion Salts and Their Isomerization to the α-Isomers
Authors: Kawafune Isao , Matsubayashi Gen-etsu 
Published: June 2006

Abstract
β-Isomers of A-type vanadium-trisubstituted nonatungstophosphate anion salts were synthesized by a condensation of NaVO3 and A-Na9[PW9O34]·7H2O in an aqueous hydrochloric acid and 1,4-dioxane mixed solution. Their geometries were characterized by IR, 31P, 51V, and 183W NMR spectroscopies. The tetrabutylammonium salt of the β-isomer, A-β-(NBun4)4H2[PV3W9O40], isomerizes to the corresponding α-isomer both in the solid state and in solution under mild conditions, which can be directly followed by FT-IR and 31P NMR spectroscopies. The kinetics of the isomerization in the solid state had a first-order rate constant at 40 °C, k1 = 2.19 × 10−7 (s−1), together with ΔH‡ = 93.3 (kJ mol−1) and ΔS‡ = −77.3 (J K−1 mol−1). On the other hand, A-β-Cs6[PV3W9O40] and A-β-(NBun4)6[PV3W9O40], which have no protons in the cation part, do not isomerize under the same conditions. The β-to-α isomerization is promoted by protonation at the bridging oxygen atom in the W–O–W bond of the polyanion.
Syntheses and Structures of a Novel Trinaphthylene Hexaimino Cryptand: Three Different Conformations of a Macrobicyclic Ligand
Authors: Sato Tadanobu , Suzuki Atsushi , Sakai Ken , Tsubomura Taro 
Published: June 2006

Abstract
A synthesis in good yield of a new hexaimino cryptand containing two tris(2-aminoethyl)amine moieties bridged by three naphthylene groups is reported. Ag+ and Cu+ cryptates of the ligand have also been prepared and characterized. The cryptand and cryptates have been structurally analyzed by X-ray diffraction, unveiling three different conformations. The macrobicyclic ligand has an anti conformation in the cryptand, but has a sym form in each cryptate. Although the Ag+ cryptates have a symmetric structure on the three arms, one of the three arms in the Cu+ complex shows remarkable bending. The bent conformation is intrinsic of the Cu+ complex, as indicated by X-ray analyses and MM2 calculations. The temperature dependence of the 1H NMR spectra has also been investigated, revealing fluxional behaviors of the ligand in each compound.
A Proton Conductive Coordination Polymer II. Proof of Proton Conduction of Dihydrogen Origin in [N,N′-Bis(2-hydroxyethyl)dithiooxamidatocopper(II)] by Protodes
Authors: Kanda Seiichi , Yamamoto Fumio 
Published: June 2006

Abstract
An example of proton conduction in a coordination polymer was examined. Dependence of the specific conductivity on hydrogen pressure was quite strong in the title compound with a few types of protodes. The mechanism of electric conduction of this coordination polymer is discussed in connection with related phenomena of the same compound.
Gram-Order Preparation of 30Si-Enriched Silica and Silicon Powders by Means of IRMPD of Disilicon Hexafluoride
Authors: Tanaka Kazunori , Isomura Shohei , Kaetsu Hayato , Yatsurugi Yoshifumi , Hashimoto Masanori , Togashi Kazuya , Arai Shigeyoshi 
Published: June 2006

Abstract
Powder silica and elemental silicon enriched with 30Si were prepared at the request of nuclear physicists who had needed the isotopic samples for their research on neutron-rich nuclei. The enrichment of 30Si was performed by means of the IRMPD of Si2F6 to SiF4 using a CO2 laser. The 30Si-enriched SiF4 was further converted either to silica by hydrolysis with aqueous ammonia or to silicon by LiAlH4 reduction to SiH4 followed by its thermal decomposition. As the final products we obtained 11.35 g of silica with 20.6% 30Si, and 3.06 g of silicon with 17.5% 30Si.
Biosynthesis of Polyester Blends by Pseudomonas sp. 61-3 from Alkanoic Acids
Authors: Kato Mikiya , Fukui Toshiaki , Doi Yoshiharu 
Published: June 2006

Abstract
Pseudomonassp. 61-3 accumulated poly(3-hydroxyalkanoates), P(3HA), in nitrogen-free media containing medium- and long-chain alkanoic acids or plant oils. The polyesters of 3HA units of even carbon numbers ranging from C4 to C12 were produced from the alkanoic acids of even carbon numbers, while those produced from the alkanoic acids of odd carbon numbers contained 3-hydroxybutyrate (3HB) and 3HA units of odd carbon numbers of C5 to C11. The strain produced simultaneously P(3HB) homopolymer and a random copolymer of 3HA units of C4 to C12 within cells from the alkanoic acids of even carbon numbers, while a copolymer of 3HB and 3-hydroxyvalerate was formed with a random copolymer of 3HA units from the alkanoic acids of odd carbon numbers. The results suggest that Pseudomonas sp. 61-3 has two types of PHA synthases with different substrate specificities.