bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of 4-piperidinomethyl-2-isopropyl-5-methylphenol on oxidative stress and calcium current
Authors: Huang Mei-Han , Liao Li-Fang , Kuo Shih-Hsien , Chen Chi-Lan , Shen Ai-Yu 
Published: August 2005

Abstract
4-Piperidinomethyl-2-isopropyl-5-methylphenol (THPI) was synthesized by reaction of thymol with piperidine and formaldehyde. The biological effect of THPI on superoxide anion scavenging activity, antiplatelet activity and calcium current inhibition were investigated. THPI (50 μm) was shown to be a scavenger of superoxide radicals in human neutrophils stimulated with N-formyl-Met-Leu-Phe (66% inhibition). Since superoxide anions are essential for platelet aggregation and L-type Ca2+-channel activity, we further found that THPI inhibited platelet aggregation induced by arachidonic acid (IC50 46.80 ± 6.88 μm). The effect of THPI on Ca2+ current in NG108–15 cells was investigated using the whole-cell voltage-clamp technique. THPI inhibited voltage-dependent L-type Ca2+ current (ICa,L). The IC50 value of THPI-induced inhibition of ICa,L was 3.60 ± 0.81 μm. THPI caused no change in the overall shape of the current-voltage relationship of ICa,L. This indicates that THPI is an inhibitor of ICa,L in NG108–15 cells. Therefore, the channel-blocking properties of THPI may contribute to the underlying mechanism by which it affects neuronal or neuroendocrine function. Furthermore, no significant cytotoxic effects of THPI (0.3–50 μm) were observed in NG108–15 cells. The results indicate that THPI is a potential reactive oxygen species scavenger and may prevent platelet aggregation or inhibit L-type Ca2+-channel activity, possibly by scavenging reactive oxygen species.
Evaluation of the cytotoxic effect of the monoterpene indole alkaloid echitamine in-vitro and in tumour-bearing mice
Authors: Jagetia Ganesh Chandra , Baliga Manjeshwar Shrinath , Venkatesh Ponemone , Ulloor Jagadish N , Mantena Sudheer Kumar , Genebriera Joseph , Mathuram V 
Published: August 2005

Abstract
The cytotoxic effect of various concentrations of echitamine chloride was studied in HeLa, HepG2, HL60, KB and MCF-7 cell lines in-vitro and in mice bearing Ehrlich ascites carcinoma (EAC). Exposure of various cells to different concentrations of echitamine chloride resulted in a concentration-dependent cell killing, and KB cells were found to be most sensitive amongst all the cells evaluated. EAC mice treated with 1, 2, 4, 6, 8, 12 or 16 mgkg−1 echitamine chloride showed a dose-dependent elevation in the anti-tumour activity, as evident by increased number of survivors in comparison with the non-drug treated controls. The highest dose of echitamine chloride (16 mg kg−1) caused toxicity in the recipient mice, therefore 12 mg kg−1 was considered the best cytotoxic dose for its anti-tumour effect. Administration of 12 mg kg−1 echitamine chloride resulted in an increase in the median survival time (MST) up to 30.5 days, which was 11.5 days higher than the non-drug treated control (19 days). Administration of 16 mg kg−1 echitamine chloride to EAC mice resulted in a time dependent elevation in lipid peroxidation that reached a peak at 6 h post-treatment, whereas glutathione concentration declined in a time dependent manner and a maximum decline was reported at 3 h post-treatment. Our study demonstrated that echitamine chloride possessed anti-tumour activity in-vitro and in-vivo.
Shaken, not stirred: a serendipitous study of ants and earthquakes
Authors: Lighton John R. B. , Duncan Frances D. 
Published: August 2005

SUMMARY
There is anecdotal evidence for profound behavioral changes prior to and during earthquakes in many organisms, including arthropods such as ants. Behavioral or physiological analysis has often, in light of these reports,been proposed as a means of earthquake prediction. We report here a serendipitous study of the effect of the powerful Landers earthquake in the Mojave Desert, USA (Richter magnitude 7.4) on ant trail dynamics and aerobic catabolism in the desert harvester ant Messor pergandei. We monitored trail traffic rates to and from the colony, trail speed, worker mass distributions, rates of aerobic catabolism and temperature at ant height before and during the earthquake, and for 3 days after the earthquake. Contrary to anecdotal reports of earthquake effects on ant behavior, the Landers earthquake had no effect on any measured aspect of the physiology or behavior of M. pergandei. We conclude that anecdotal accounts of the effects of earthquakes or their precursors on insect behavior should be interpreted with caution.
Ontogenetic changes in the response properties of individual, primary auditory afferents in the vocal plainfin midshipman fish Porichthys notatus Girard
Authors: Sisneros Joseph A. , Bass Andrew H. 
Published: August 2005

SUMMARY
The auditory system of adult midshipman fish Porichthys notatusGirard is an important sensory receiver system used during intraspecific social communication to encode conspecific vocalizations, but the response properties and function of this system in the pre-adult stages are unknown. Midshipman fish, like other teleosts, use the saccule as the main acoustic end organ of the inner ear. In this study, we examined the discharge properties and the frequency response dynamics of auditory saccular afferent neurons in pre-adult midshipman (∼4–12 months of age) to determine whether encoding of auditory information, inclusive of conspecific vocalizations,changes across life history stages. Extracellular single unit recordings were made from saccular afferents while sound was presented via an underwater speaker. Comparisons with adult data show that the resting discharge rate and auditory threshold sensitivity increased with age/size,while temporal encoding of frequency did not show any significant shifts. The results indicate that the saccular afferents of juveniles, like those of non-reproductive adults, are best adapted to temporally encode the low frequency components (≤100 Hz) of midshipman vocalizations. This report represents the first in vivo investigation of age-related changes in the encoding properties of individual auditory neurons for any fish species.
The aerodynamic effects of wing–wing interaction in flapping insect wings
Authors: Lehmann Fritz-Olaf , Sane Sanjay P. , Dickinson Michael 
Published: August 2005

SUMMARYWe employed a dynamically scaled mechanical model of the small fruit fly Drosophila melanogaster (Reynolds number 100–200) to investigate force enhancement due to contralateral wing interactions during stroke reversal (the `clap-and-fling'). The results suggest that lift enhancement during clap-and-fling requires an angular separation between the two wings of no more than 10–12°. Within the limitations of the robotic apparatus, the clap-and-fling augmented total lift production by up to 17%, but depended strongly on stroke kinematics. The time course of the interaction between the wings was quite complex. For example, wing interaction attenuated total force during the initial part of the wing clap, but slightly enhanced force at the end of the clap phase. We measured two temporally transient peaks of both lift and drag enhancement during the fling phase: a prominent peak during the initial phase of the fling motion, which accounts for most of the benefit in lift production, and a smaller peak of force enhancement at the end fling when the wings started to move apart. A detailed digital particle image velocimetry (DPIV) analysis during clap-and-fling showed that the most obvious effect of the bilateral `image' wing on flow occurs during the early phase of the fling, due to a strong fluid influx between the wings as they separate. The DPIV analysis revealed, moreover, that circulation induced by a leading edge vortex (LEV) during the early fling phase was smaller than predicted by inviscid two-dimensional analytical models, whereas circulation of LEV nearly matched the predictions of Weis-Fogh's inviscid model at late fling phase. In addition, the presence of the image wing presumably causes subtle modifications in both the wake capture and viscous forces. Collectively, these effects explain some of the changes in total force and lift production during the fling. Quite surprisingly, the effect of clap-and-fling is not restricted to the dorsal part of the stroke cycle but extends to the beginning of upstroke, suggesting that the presence of the image wing distorts the gross wake structure throughout the stroke cycle.
Phylogenetic approaches in comparative physiology
Authors: Garland Theodore , Bennett Albert F. , Rezende Enrico L. 
Published: August 2005

SUMMARYOver the past two decades, comparative biological analyses have undergone profound changes with the incorporation of rigorous evolutionary perspectives and phylogenetic information. This change followed in large part from the realization that traditional methods of statistical analysis tacitly assumed independence of all observations, when in fact biological groups such as species are differentially related to each other according to their evolutionary history. New phylogenetically based analytical methods were then rapidly developed, incorporated into `the comparative method', and applied to many physiological, biochemical, morphological and behavioral investigations. We now review the rationale for including phylogenetic information in comparative studies and briefly discuss three methods for doing this(independent contrasts, generalized least-squares models, and Monte Carlo computer simulations). We discuss when and how to use phylogenetic information in comparative studies and provide several examples in which it has been helpful, or even crucial, to a comparative analysis. We also consider some difficulties with phylogenetically based statistical methods, and of comparative approaches in general, both practical and theoretical. It is our personal opinion that the incorporation of phylogeny information into comparative studies has been highly beneficial, not only because it can improve the reliability of statistical inferences, but also because it continually emphasizes the potential importance of past evolutionary history in determining current form and function.
Structure and function of the esophagus of the American alligator(Alligator mississippiensis)
Authors: Uriona T. J. , Farmer C. G. , Dazely J. , Clayton F. , Moore J. 
Published: August 2005

SUMMARYEsophageal structure and function were studied in juvenile American alligators (Alligator mississippiensis). The anatomy of alligators differs from humans in several important aspects: the crocodilian esophagus is more muscular and is composed entirely of smooth muscle. Functionally, the crocodilian esophagus is similar to that of mammals, but alligators have peak esophageal peristaltic pressures that are 2–3-fold greater than pressures in the human esophagus. As is found in humans, the incidence of esophageal reflux increased in postprandial animals compared with the fasting state. We observed a large increase in pressure in the lower esophageal sphincter (LES) during ventilation that ranged from 200% to 3000% of the pressures measured during apnea. These pressure changes appear to be intrinsic to the LES. Alligators lack a mammalian-type diaphragm; thus, there is no crural diaphragmatic contribution to LES pressure. These features recommend the alligator as a useful model for the study of regulation of the LES.
Geometry of elytra opening and closing in some beetles (Coleoptera,Polyphaga)
Authors: Frantsevich Leonid , Dai Zhendong , Wang Wei Ying , Zhang Yafeng 
Published: August 2005

SUMMARYElytra in beetles move actively, driven by their own muscles, only during transient opening and closing. The kinematics of these movements have been inadequately described, sometimes controversially. Our goal was a quantitative 3-D description of diverse active movements of the elytra, in terms of directions of the axes of elytra rotation.Broad opening and closing was video recorded in beetles, tethered by the mesothorax, and has been analyzed frame by frame. For tracing, small dots or straw arms were glued to the elytra. Opening and closing traces coincided. The trace of the elytron apex was a flat circular arc about the axis of abduction–adduction (AAA). The rising hemiaxis pointed contralaterad. The AAA was tilted forwards in Melolontha hippocastani, Allomyrina dichotoma and Prionus coriarius but backwards in Chalcophora mariana. In Cetonia aurata, the AAA had a low elevation and a strong backward orientation. If another elytra-fixed point was traced in addition to the apex (in M. hippocastani and P. coriarius), then secondary rotation about the sutural edge (supination on opening) occurred. Modeling of abduction–adduction revealed that the elytron rose on opening if the AAA pointed contralaterad. The more the AAA was tilted forward, the more negative was the attack angle of the open elytra. The negative attack angle was partly compensated by positive body pitch and, more effectively, by supination of the costal edge about the sutural edge.The initial stage of opening included elevation of closed elytra (by 10–12°) and partition to the sides, combined with an inward turn(&lt;2–3°). Axis of rotation at this stage presumably coincided with the AAA. Movement of one elytron with respect to the opposite one at the beginning of opening followed the shallow arc convex down. The geometry of this relative movement describes the initial partition of the elytra and release of the sutural lock.
Influence of host size on the clutch size and developmental success of the gregarious ectoparasitoid Eulophus pennicornis (Nees)(Hymenoptera: Braconidae) attacking larvae of the tomato moth Lacanobia oleracea (L.) (Lepidoptera: Noctuidae)
Authors: Bell H. A. , Marris G. C. , Prickett A. J. , Edwards J. P. 
Published: August 2005

SUMMARY
The relationship between clutch size, host size and progeny survival in the gregarious ectoparasitoid Eulophus pennicornis was investigated in a number of scenarios. When naive parasitoids were exposed singly to Lacanobia oleracea hosts, clutch size was strongly correlated with the size of the host. However, survival of parasitoid offspring was negatively affected by the size of the host such that, in larger hosts, greater wasp larval and pupal mortality was recorded. As a result, no gain in realised fecundity was achieved through parasitizing L. oleracea larvae of mass &gt;0.4 g over hosts of mass between 0.2–0.3 g. When exposed to populations of mixed stadium hosts (larvae in the fourth, fifth and sixth instars) during the entire lifespan of the wasp, host size and clutch size were correlated in early ovipositions (first three ovipositions). However, as the wasps aged, the relationship was much less apparent. When the parasitoid was restricted to foraging upon populations of sixth instar hosts only, no relationship between host size and clutch size was apparent. Exposure of the parasitoid to mixed and fixed stadium host populations showed that final(sixth) stadium hosts were the most frequently parasitized (ca. 96% of parasitized hosts) and that the average numbers of eggs laid per wasp, and the number of hosts parasitized, was significantly lower when the parasitoid was provided with fourth or fifth instar hosts only. The results indicate that the reproductive success of E. pennicornis does not increase with increasing host size or greater resource availability above a certain threshold, and that the physiological status of the host at the time of parasitism is the governing factor determining oviposition decisions and parasitoid survival. We conclude that E. pennicornis has been selected to preferentially utilize those hosts that maximize progeny survival and to adapt clutch size to the size of such hosts. We hypothesize that the major driver leading to the evolution of this strategy is the ability of the parasitoid to physiologically regulate the host.
Molecule-Based Magnets in Heterospin Systems
Authors: Koga Noboru , Karasawa Satoru 
Published: August 2005

Abstract
Our approaches to the molecule-based magnets by using heterospin systems are reviewed. In our heterospin systems consisting of the organic 2p spins and the metal ion 3d spins, various pyridines carrying the organic spins were used as binding ligands for 3d metal ions. Carbenes generated by photolysis of diazo groups and persistent N-tert-butylaminoxyl radicals were employed as the organic spin sources. First, various model complexes were prepared and their magnetic couplings between the organic spin and the metal ion through the pyridine ligand were revealed. Based on the results of magnetic studies on model complexes, ferri- and ferromagnetic complexes having linear chain structures were designed and successfully prepared. When our heterospin systems were used under solution conditions, new fields were opened. Assemblies formed in frozen solution had magnetic behaviors exhibiting slow magnetic relaxations. Especially, when the anisotropic metal ion, high-spin cobalt(II) ion, was used as the metal ion in our heterospin system, the complex formed in frozen solution functioned as a single-molecule magnet (SMM). Such formation of a monometallic SMM was the first example reported.
Ion-Association Analysis between Inorganic Anions and Symmetrical Tetraalkylammonium Ions in Aqueous-Acetonitrile Media by Capillary Zone Electrophoresis
Authors: Mbuna Julius , Takayanagi Toshio , Oshima Mitsuko , Motomizu Shoji 
Published: August 2005

Abstract
Weak ion-association equilibrium was analyzed in a water-acetonitrile solution at 25 °C by capillary zone electrophoresis using an ordinary silica capillary. The ion associates examined were formed between some inorganic anions and symmetrical tetraalkylammonium ions, where a series of acetonitrile compositions up to 62.2% (m/m) were investigated. Ion-association constants, Kass, were determined by analyzing the changes in the electrophoretic mobility; the Kass values for most of the anions increased up to about 47% (m/m) acetonitrile, beyond which they remained constant, or decreased slightly. The ion-association equilibrium between tetramethylammonium and bromide ions in aqueous-acetonitrile and in aqueous-ethanol media were compared through the Gibbs free energy of transfer, which revealed that the extent of the equilibrium in aqueous-acetonitrile media is dependent mainly on the increasing instability of Br−. On the other hand, those in aqueous-ethanol media depend on the instabilities of both tetramethylammonium and bromide ions.
Selective C–C Bond Activation of 2-Aryl-1-methylenecyclopropanes Promoted by Ir(I) and Rh(I) Hydrido Complexes. Mechanism of Ring-Opening Isomerization of the Strained Molecules
Authors: Nishihara Yasushi , Yoda Chikako , Itazaki Masumi , Osakada Kohtaro 
Published: August 2005

Abstract
[IrH(CO)(PPh3)3] promotes ring opening of 2-phenyl-1-methylenecyclopropane at room temperature to produce the Ir complex with a chelating 2-phenyl-3-butenyl ligand, [Ir{η2-CH2CH(Ph)CH=CH2-κC1}(CO)(PPh3)2] (1). The reaction of excess 2-phenyl-1-methylenecyclopropane with [IrH(CO)(PPh3)3] at 50 °C yields [Ir{η2-(o-C6H4)CH(Me)CH=CH2-κC1}(CO)(PPh3)2] (2), accompanied by the formation of 1-phenyl-1,3-butadiene and 2-phenyl-1,3-butadiene. 2,2-Diphenyl-1-methylenecyclopropane reacts with [IrH(CO)(PPh3)3] to afford [Ir{η2-CH2CPh2CH=CH2-κC1}(CO)(PPh3)2] (3) at 50 °C and [Ir{η2-(o-C6H4)CMe(Ph)CH=CH2-κC1}(CO)(PPh3)2] (4) at 100 °C. Heating a solution of 3 at 100 °C also forms 4 quantitatively. X-ray crystallography of 3 reveals a penta-coordinated structure around the Ir center bonded to a chelating 2,2-diphenyl-3-butenyl ligand. The reactions of 2,2-diphenyl-1-methylenecyclopropane and of 2,2-di(4-fluorophenyl)-1-methylenecyclopropane with [RhH(CO)(PPh3)3] at room temperature yield [Rh{η2-CH2CAr2CH=CH2-κC1}(CO)(PPh3)2] (5a: Ar = Ph, 5b: Ar = C6H4-F-4). The reactions at 50 °C cause ring opening of the substrate and orthometalation of the phenyl group to afford [Rh{η2-(o-C6H4)CMe(Ph)CH=CH2-κC1}(CO)(PPh3)2] (6a) and [Rh{η2-(o-C6H3-F-4)CMe(C6H4-F-4)CH=CH2-κC1}(CO)(PPh3)2] (6b), respectively. Formation of 1,1-diaryl-1,3-butadiene is observed during the reaction. Heating a solution of 5a at 50 °C produces 1,1-diphenyl-1,3-butadiene and an allylrhodium complex, 8, rather than 6a, although the reaction of excess 2,2-diphenyl-1-methylenecyclopropane with 5a at 50 °C affords 6a in 60%. The mechanisms of the above reactions are discussed based on the products and reaction rates. Coordination of P(OMe)3 to the Rh center of 5a causes insertion of the CO ligand into the Rh–C bond to afford [Rh{η2-CO-CH2CPh2CH=CH2-κC1}(P(OMe)3)3] (7).
A New Method for the Synthesis of Carboxylic Esters and Lactones with Di-2-thienyl Carbonate (2-DTC) by the Promotion of DMAP and Iodine
Authors: Oohashi Yoshiaki , Fukumoto Kentarou , Mukaiyama Teruaki 
Published: August 2005

Abstract
The esterification of carboxylic acids with alcohols by using di-2-thienyl carbonate (2-DTC) in the presence of a catalytic amount of 4-(dimethylamino)pyridine (DMAP) proceeded smoothly to afford the corresponding esters in good-to-high yields along with 2(5H)-thiophenone. This esterification was accelerated by the addition of an equimolar amount of iodine to afford the esters in higher yields within a shorter reaction time. Further, cyclization of ω-hydroxycarboxylic acids with an equimolar amount of 2-DTC in the presence of a catalytic amount of DMAP, followed by the addition of 1–4 equimolar amounts of iodine, afforded the corresponding lactones in good-to-high yields under mild conditions. This method was successfully employed in the synthesis of erythro-aleuritic acid lactone.
Substituent-Control of Two Modes of Intramolecular Reactions of Allyloxy-Silyllithiums and Propargyloxy-Silyllithiums
Authors: Kawachi Atsushi , Maeda Hirofumi , Tamao Kohei 
Published: August 2005

Abstract
Intramolecular reactions of the [(allyloxy)silyl]lithiums and the [(propargyloxy)silyl]lithiums have been investigated. The [(allyloxy)silyl]lithiums proceed in two reaction modes depending on the electronic effect of the substituents at the terminus of the olefin. The [(allyloxy)silyl]lithiums bearing hydrogen, n-C6H13, or trimethylsilyl substituent undergo the [2,3]-sila-Wittig rearrangement to afford the lithium allylsilanolates, while those bearing the phenyl, thienyl, or triphenylsilyl substituent experience the 4-exo-trig cyclization and subsequent 1,3-cycloelimination to give the lithium cyclopropylsilanolates. On the other hand, the [(propargyloxy)silyl]lithiums preferentially undergo the 4-exo-dig cyclization over the [2,3]-sila-Wittig rearrangement in all cases.
Total Synthesis of (+)-Tanikolide, Using Regioselective Elimination of a Vicinal Dibromoalkane
Authors: Ohgiya Tadaaki , Nakamura Kensuke , Nishiyama Shigeru 
Published: August 2005

Abstract
Total synthesis of (+)-tanikolide, a bioactive δ-lactone of marine origin, was successfully accomplished by utilizing a bromoalkene derivative conveniently synthesized from the corresponding 1-acyloxy-2,3-dibromoalkane by the regioselective and mild HBr-elimination reaction, along with the Pd-mediated C–C coupling reaction and the Sharpless asymmetric epoxidation as key steps.
Decomposition of Dichlorodifluoromethane with Simultaneous Halogen Fixation by Vanadium Oxide Supported on Magnesium Oxide
Authors: Tamai Tsukasa , Inazu Koji , Aika Ken-ichi 
Published: August 2005

Abstract
Dichlorodifluoromethane (CCl2F2, 1% in He) decomposition with simultaneous halogen fixation by vanadium oxide supported on magnesium oxide was studied at 723 K in a flow apparatus. The pretreatment condition and vanadium loading of supported vanadium oxide samples affected the CCl2F2 decomposition efficiency. Through characterization studies (XRD, IR, Raman, and XPS) and reference experiments, Mg3(VO4)2 was revealed to be the active species to initiate CCl2F2 decomposition, leading to MgF2, MgCl2, and CO2 formation. The model experiments also suggested a detailed mechanism that VOCl3 was formed from Mg3(VO4)2 by a reaction with CCl2F2 or the major intermediate compound CCl4, and that VOCl3 reacted with MgO to regenerate Mg3(VO4)2 and to promote chlorine fixation as MgCl2.