bluuebunny/crossref_metadata_2025 huggingface dataset:
An exploratory ab initio study of the SN2 reaction of 1,3,3-trimethyltriazene with halide ions
Authors: Doucet Katherine G , Pye Cory C , Enright Thomas G
Published: October 2007

Methyltriazene and the O6 oxygen of guanine are believed to undergo a bimolecular nucleophilic substitution (SN2) reaction to form methylguanine, which is proposed to be responsible for the cytotoxic properties of triazene-containing anti-neoplastic agents, such as Dacarbazine. To better understand the proposed mechanism of triazene-containing anti-neoplastic agents, a series of ab initio studies investigating the SN2 reaction between methyltriazenes and halide ions were undertaken. The results of our investigation of the SN2 reaction between 1,3,3-trimethyltriazene and the halide ions are presented here.Key words: triazene, trimethyltriazene, Dacarbazine, Temozolomide, bimolecular nucleophilic substitution reaction.
Coriolis coupling effects on energy transfer: classical-trajectories analysis for CO2 + Ar collisions
Authors: Borges E , Braga J P
Published: October 2007

Energy transfer on CO2 + Ar collisions is studied by performing classical-trajectories simulations in a non-rigid potential-energy surface. Partition of molecular kinetic energy into vibration, rotation, and Coriolis coupling is made in a Cartesian coordinates system, coupled to vibrational normal modes. Initial atomic translational energies are selected from a range of 0.004–0.4 au, and initial molecular rotational states are fixed at rotational quantum numbers j, equal to 1, 20, 40, and 60. Effects of these different initial conditions are investigated, and the Coriolis influence on the energy transferred is analyzed.Key words: Coriolis coupling, energy, classical trajectories.
Ceric-sulfate-catalyzed synthesis of 14-aryl- or 14-alkyl-14H-dibenzo[aj]xanthene under conventional heating and microwave irradiation
Authors: Selvam Nagarajan Panneer , Shanthi Gnanamani , Perumal Paramasivan T
Published: October 2007

A simple and facile procedure for the synthesis of 14-aryl- or 14-alkyl-14H-dibenzo[aj]xanthenes is described. The procedure takes place by the one-pot condensation of 2-naphthol with aldehydes in the presence of anhydrous ceric sulfate as the catalyst under solvent-free conventional heating and microwave irradiation.Key words: xanthene, one-pot condensation, aldehyde, 2-naphthol, ceric sulfate, solvent-free, microwave irradiation.
Differences in Optical Transport Properties between Human Meridian and Non-meridian
Authors: Yang Hong-Qin , Xie Shu-Sen , Liu Song-Hao , Li Hui , Guo Zhou-Yi
Published: October 2007

This study is to present a new scheme for the detection of human meridian system non-invasively. The optical transport properties along the pericardium meridian and a non-meridian path about 1 cm away from the meridian were measured non- invasively on 20 healthy people in vivo. 633 nm, 658 nm and 785 nm red lasers were used for irradiation, and the diffuse light emittances at different points on meridian and non-meridian directions were collected respectively and compared. Our study suggested that the light propagation characteristics along both the meridian and non-meridian directions conformed to the Beer's exponential attenuation law. Statistical analysis of the results suggested that the optical properties of human meridian differ from those of the surrounding tissue ( p < 0.05), and the light attenuation is less when propagating along the pericardium meridian than along the non-meridian direction. These findings not only confirmed the objective existence of acupuncture meridians, but also shed new light on the understanding of meridians.
Hepatoprotective and Antioxidant Effects of Ethanol Extract fromPhellinus merrilliion Carbon Tetrachloride-Induced Liver Damage
Authors: Chang Heng-Yuan , Peng Wen-Huang , Sheu Ming-Jyh , Huang Guan-Jhong , Tseng Mu-Chuan , Lai Ming-Tsung , Ho Yu-Ling , Chang Yuan Shiun
Published: October 2007

In the present study, we investigated the hepatoprotective and antioxidant capacities of ethanol extract of Phellinus merrillii (PM) on carbon tetrachloride-induced hepatotoxicity. In high-performance liquid chromatography (HPLC) analysis, the finger print chromatogram of PM was established. Both hispolon and PM showed a similar peak at the retention time of 6 min. This implied that PM did contain the active ingredient of hispolon. Treatment with PM (0.5, 1 and 2 g/kg) prior to the administration of carbon tetrachloride (1.5 ml/kg in olive oil, 20%) significantly prevented the increased serum alanine aminotransferase (s-GOT) and serum aspartate aminotransferase (s-GPT) in a dose-dependent manner. We also found that the incidences of ballooning degeneration, necrosis and portal triaditis were lowered in the group pretreated with PM. Carbon tetrachloride induces up-regulation of antioxidant enzymes, including superoxide dismutase (SOD) (86.6%), catalase (58.8%) and glutathione peroxidase (GPx)(64.7%) in the liver. Pretreatment with PM significantly reduced the all these antioxidant enzyme activities. Therefore, we verified that ethanol extract of PM has the hepatoprotective and antioxidant capacities on rats.
The Effect ofGinkgo bilobaExtract (EGb 761) Pretreatment on Intestinal Epithelial Apoptosis Induced by Intestinal Ischemia/Reperfusion in Rats: Role of Ceramide
Authors: Liu Ke-Xuan , He Wei , Rinne Timo , Liu Ying , Zhao Ming-Qi , Wu Wei-Kang
Published: October 2007

Apoptosis was demonstrated to be a major mode of intestinal epithelial cell death caused by intestinal ischemia/reperfusion ( II / R ). Ceramide has been proposed as a messenger for apoptosis. The present study was aimed to investigate the effect of Ginkgo biloba extract 761 (EGb 761) pretreatment on II / R -induced intestinal mucosal epithelial apoptosis in rats and the mechanism related to ceramide. The rat model of II / R injury was produced by clamping superior mesenteric artery for 60 min followed by reperfusion for 180 min. Twenty four rats were randomly allocated into Sham, II / R and EGb + II / R groups. In EGb + II / R group, EGb 761 (100 mg/kg per day) was administered intragastrically for 7 days before the surgery. Animals in II / R and sham groups were treated with equal volume of normal saline solution. Intestinal mucosal epithelial apoptosis was detected via electron microscopy and TUNEL method. Lipid peroxidation in intestinal mucosa was determined by detecting the malondialdehyde level and the activities of superoxide dismutase and peroxidase glutathione. The ceramide generation and sphingomyelinase (SMase) mRNA expression in intestinal mucosa were determined by high performance, thin layer chromatography, and RT-PCR, respectively. II / R caused intestinal mucosal epithelial apoptosis and over-production of the ceramide accompanied by up-regulation of SMase mRNA expression and increases of lipid peroxidation. EGb 761 pretreatment significantly decreased apoptosis index, and concurrently reduced the ceramide generation accompanied by down-regulation of SMase expression and inhibition of lipid peroxidation. The findings indicate that EGb 761 pretreatment attenuates II / R -induced intestinal epithelial apoptosis, which might be attributable to its antioxidant action of mediating ceramide pathway.
In vivo Antitumoral Effect of Plantago major L. Extract on Balb/C Mouse with Ehrlich Ascites Tumor
Authors: Ozaslan Mehmet , Didem Karagöz I. , Kalender M. Emin , Kilic I. Halil. , Sari Ibrahim , Karagöz Alper
Published: October 2007

The aim of this study is to investigate the antitumor activity of Plantago major L. extract in Ehrlich ascites tumor (EAT) bearing Balb/C mice in vivo. Thirty male Balb/C mice were divided into 5 groups: 3 treatment groups and 2 control groups (6 per group). Treatment groups and the negative control group were injected with EAT (1 × 106 cells) intraperitoneally to develop ascites tumor. P. major L. extract (1%, 2% and 3% concentration extracts, 0.1 ml/day/mouse) were given p.o. for 10 alternate days. The control group was treated with 0.9% NaCl solution (0.1 ml/day/mouse). The changes of body weight in animals were recorded. On the 11th day, all of the mice were sacrified and their tissues were stained with haematoxylen and eosin for pathological studies. Body weights of in 3 treatment groups and the negative control group were elevated because of tumor burden. The maximal weight gain was recorded in the negative control group and the minimal weight gain was recorded in Group I. Pathological studies showed that P. major L. extract (especially 1% concentration) has inhibitive effect on EAT. P. major has an inhibitory effect on EAT in a dose dependent manner.
Eriobotrya japonica Counteracts Reactive Oxygen Species and Nitric Oxide Stimulated by Chloramphenicol
Authors: Eraso Alberto Jorge , Albesa Inés
Published: October 2007

Chloramphenicol is a toxic antibiotic used for certain infections, though aplastic anaemia is one of its side-effects. The results of our experiments showed that blood cells suffered oxidative stress in the presence of chloramphenicol, with a significant increase in reactive oxygen species (ROS) detected by luminol-chemiluminescence (CL). The extract of fruits of Eriobotrya japonica markedly decreased ROS in leukocytes and erythrocytes, the oxidative stress caused by this antibiotic. Nitro Blue Tetrazolium (NBT) assay with purified leukocytes demonstrated that the antioxidant action of E. japonica caused an intracellular reduction in ROS, and that the extracts decreased these promoters of oxidative stress to normal levels in the cytoplasm. Determinations of nitric oxide (NO) generation indicated that E. japonica extracts also inhibited the stimuli of NO provoked by chloramphenicol. This study showed that the immediate antioxidant effect of E. japonica could be associated with the action of vitamin A. The protective action of this fruit was seen on mature leukocytes and erythrocytes, beneficial effect on blood cells suggest that its extract could be used as an antioxidant agent complementing the administration of chloramphenicol, as a modern-day extension to its traditional use in Chinese medicine.
ELECTRONIC STRUCTURE AND QUANTUM PHASE TRANSITION IN MULTI-WALL CARBON NANOTUBES
Authors: LIANG SHI-DONG
Published: October 2007

The electronic structure of the multi-wall carbon nanotubes (MWCN) is studied theoretically by the tight-binding approach. The interwall coupling between layers plays an essential role in the electronic structure. With an increase of the interwall coupling, the energy gap of the semiconducting MWCNs will decrease and eventually vanish, giving rise to the semiconductor–metal quantum phase transition. The metallic layer in the MWCN dominates the electronic structure characteristics near the Fermi level (gapless).
THERMAL CONDUCTIVITY OF SOLIDS AT HIGH TEMPERATURES AND HIGH PRESSURES
Authors: SHARMA S. K. , SRIVASTAVA S. K. , SHARMA B. S.
Published: October 2007

In the present study, we have extended the model due to Tang1based on the thermal conductivity equation due to Leibfried and Schlomann12so as to make it applicable for a wide range of pressures and temperatures. We have used the Stacey14,15equations of state (EOS) for determining the thermoelastic properties of NaCl , KCl and Al2O3at high pressures and high temperatures. These are used to estimate the variations of thermal conductivity with the change in pressure along different isotherms at selected temperatures. The results thus obtained are compared with the values derived from relations, which reproduced available experimental data well at low temperatures and low pressures. Experimental data at high temperatures and high pressures are not available. A close agreement between the two sets of data reveals the validity of the present work.
THE FUZZY ANT SYSTEM FOR THE VEHICLE ROUTING PROBLEM WHEN DEMAND AT NODES IS UNCERTAIN
Authors: TEODOROVIĆ DUŠAN , LUČIĆ PANTA
Published: October 2007

In some distribution systems, only approximate values of demand at nodes are known. In this research, the new type of the intelligent vehicle routing system has been developed. Demand at the nodes is treated as a fuzzy number and actual demand value is known only after the visit to the node. The model developed is based on the Fuzzy Arithmetic Rules, Fuzzy Logic and Ant System. Numerical experiments indicate that the developed Fuzzy Ant System is very promising.
BUILDING A KNOWLEDGE BASE FOR IMPLEMENTING A WEB-BASED COMPUTERIZED RECOMMENDATION SYSTEM
Authors: VELÁSQUEZ JUAN D. , PALADE VASILE
Published: October 2007

Understanding the web user browsing behaviour in order to adapt a web site to the needs of a particular user represents a key issue for many commercial companies that do their business over the Internet. This paper presents the implementation of a Knowledge Base (KB) for building web-based computerized recommender systems. The Knowledge Base consists of a Pattern Repository that contains patterns extracted from web logs and web pages, by applying various web mining tools, and a Rule Repository containing rules that describe the use of discovered patterns for building navigation or web site modification recommendations. The paper also focuses on testing the effectiveness of the proposed online and offline recommendations. An ample real-world experiment is carried out on a web site of a bank.
DETECTION AND PREDICTION OF RARE EVENTS IN TRANSACTION DATABASES
Authors: BERBERIDIS CHRISTOS , VLAHAVAS IOANNIS
Published: October 2007

Rare events analysis is an area that includes methods for the detection and prediction of events, e.g. a network intrusion or an engine failure, that occur infrequently and have some impact to the system. There are various methods from the areas of statistics and data mining for that purpose. In this article we propose PREVENT, an algorithm which uses inter-transactional patterns for the prediction of rare events in transaction databases. PREVENT is a general purpose inter-transaction association rules mining algorithm that optimally fits the demands of rare event prediction. It requires only 1 scan on the original database and 2 over the transformed, which is considerably smaller and it is complete as it does not miss any patterns. We provide the mathematical formulation of the problem and experimental results that show PREVENT's efficiency in terms of run time and effectiveness in terms of sensitivity and specificity.
FREQUENCY-DEPENDENT HYPERPOLARIZABILITY OF BENZENE DERIVATIVES: AB-INITIO CALCULATIONS
Authors: MAKWANI DIKSHA , VIJAYA R.
Published: October 2007

Structure–property relationship and dispersion effects for disubstituted benzene molecules have been investigated. Ab-initio calculations of the first hyperpolarizabilities (β) of donor–acceptor benzene derivatives show that the magnitude of β depends upon the availability of the lone pair of electrons on the nitrogen atom to conjugate with the benzene ring. The HOMO–LUMO energy gap and β have an inverse relationship. From the dispersion studies, it is observed that the first resonance peak shifts towards lower frequencies as the donor/acceptor capacity increases.
BRAGG-MATCHED PHOTOREFRACTIVE TWO-BEAM COUPLING IN ORGANIC–INORGANIC HYBRIDS
Authors: EVANS D. R. , COOK G.
Published: October 2007

This review article presents the concept of photorefractive beam coupling in hybrid photorefractive cells comprising a liquid crystal layer adjacent to inorganic photorefractive windows. The roles of the liquid crystal layer and the photorefractive windows, as well as the overall advantages of this architecture, are explained. The mechanism involved and the required window parameters to break the local alignment symmetry in order to achieve Bragg-matched two-beam coupling in a liquid crystal layer are discussed.
DEVELOPMENT OF MAGNETIC MATERIALS FOR PHOTONIC APPLICATIONS
Authors: BAERT KASPER , LIBAERS WIM , KOLARIC BRANKO , VALLÉE RENAUD A. L. , VAN DER AUWERAER MARK , CLAYS KOEN , GRANDJEAN DIDIER , DI VECE MARCEL , LIEVENS PETER
Published: October 2007

In this manuscript, the synthesis and characterization of superparamagnetic particles and their silica-coated counterparts as building blocks for magnetic photonic crystals is fully described. The advantages and disadvantages of the presented synthetic method are discussed. Preliminary results considering the presence of magnetic species within a photonic crystal are also presented. Suppression of emission of the quantum dots within photonic crystals is attributed to a decrease of the number of available photonic modes for radiative decay. The presence of materials with permanent magnetic moments within photonic crystals shows that suppression of their emission is scaled with the strength of the magnetic field.
NONLINEAR AND ELECTRO-OPTICS OF NANO-DISPERSED NEMATIC LIQUID CRYSTALS WITH TUNABLE NEGATIVE-, ZERO-, AND POSITIVE INDICES
Authors: KHOO I. C. , DIAZ A. , KWON D. , WERNER D. H. , LIOU J. , STINGER MIKE , PARK J. H. , KUBO S. , MALLOUK T.
Published: October 2007

We present a review of recent progress in the studies of the nonlinear- and electro-optics of liquid crystals, particularly in their meta-material forms. An analytical expression for the "ultimate" optical nonlinearity of nematic liquid crystals is obtained, and several routes to realizing such optical nonlinearities are discussed. We also describe two approaches for realizing tunable or reconfigurable negative-zero-positive index materials: (1) planar nano-structured frequency selective surfaces [FSS] containing nematic liquid crystals; (2) core-shell nano-spheres randomly distributed in bulk nematic liquid crystal matrix. Such metamaterials can be designed for applications in the visible-infrared, as well as Terahertz and microwave regimes. These liquid crystalline meta-materials are capable of supra-nonlinearities characterized by refractive index changing coefficients of over 1 cm2/watt and microseconds response times.
SIMULATION AND ANALYSIS OF ADAPTIVE AGENTS: AN INTEGRATIVE MODELING APPROACH
Authors: BOSSE TIBOR , JONKER CATHOLIJN M. , TREUR JAN
Published: October 2007

Agent-based simulation methods are a relatively new way to address complex systems. Usually, the idea is that the agents used are rather simple, and the complexity and adaptivity of such a system are modeled by the interaction between these agents. However, another way to exploit agent-based simulation methods is by use of agents that themselves also have certain forms of learning or adaptation. In order to simulate adaptive agents with abilities matching those of their real-world biological or societal counterparts, a natural approach is to incorporate certain adaptation mechanisms such as classical conditioning into agent models. Existing models for adaptation mechanisms are usually based on quantitative, numerical methods, and in particular, differential equations. Since agent-based simulation is usually based on qualitative, logical languages, these quantitative models are often not directly appropriate as an input in the context of agent-based simulation. To deal with this problem, this paper puts forward an integrative approach to simulate and analyze the dynamics of complex systems, in particular a conditioning process of an adaptive agent, integrating quantitative, numerical and qualitative, logical aspects within one expressive temporal specification language. To obtain a simulation model, an executable sublanguage of this language is used to specify the agent's adaptation mechanism in detail. For analysis and validation, in the proposed approach both properties characterising the externally observable adaptive behavior and properties characterizing the dynamics of internal intermediate states have been identified, formally specified and automatically checked on the generated simulation traces. As part of the latter, an approach to (formally) specify and check representational relations for intermediate, internal agent states is put forward. This enables verification of whether the representational content of an intermediate state a modeller has in mind indeed is in accordance with the agent model's internal dynamics. For a biological agent with known neural mechanisms, such as Aplysia, the modeling approach incorporates high-level modeling of neural states occurring as intermediate states and relates them to their representational content specification. This provides the possibility to validate not only the resulting observable behavior of a simulation model against the observable behavior of the agent in the real world, but also the intermediate states of the agent in the model against the intermediate states of the agent in the world.
SIZE INSTABILITIES IN THE RING AND LINEAR ARRAYS OF CHAOTIC SYSTEMS
Authors: QI GUANXIAO , HUANG HONGBIN , WANG HAIJUN
Published: October 2007

We investigate the dynamical stabilities of ring and linear arrays of chaotic oscillators with asymmetric nearest-neighbor and long-range couplings. It is shown that the instabilities of complete chaotic synchronization occur as the numbers of oscillators are increased beyond critical values which depend on the coupling schemes and coupling parameters of the systems. Based on the master stability function and eigenvalue analysis methods, we give the semi-analytical relations between the critical values and the coupling parameters. Results are demonstrated with numerical simulations in a set of coupled Lorenz oscillators.
A knowledge unique: the life of the pioneering explorer and palaeontologist, Dorothea Bate (1878–1951)
Authors: Shindler Karolyn
Published: October 2007

Dorothea Bate is recognized as a pioneer of archaeozoology – the study of animal bones from archaeological sites. She also worked extensively on cave sites. Her research in Cyprus, Crete, Majorca and Menorca, as well as pre World War II Palestine, showed her holistic approach to the use of animal bones in order to deduce dates, climate and environment of the sites. She was the first woman to work as a scientist at the Natural History Museum, then known as the British Museum (Natural History), and her research reports on the fossil faunas are still being used today.
Nancy Kirk: turning the world of graptolites upside down
Authors: Wyatt A. R.
Published: October 2007

Nancy Kirk was a protégée of O. T. Jones. Her early, unpublished, field studies in the Welsh Borders were an important foundation for some of the work on faunal distributions by Oxford workers in the 1960s and for regional studies by a group at Cambridge in the 1980s and 1990s. From the start, her graptolite work proved controversial but, for many people, enlivening. Interpretations (produced in conjunction with Denis Bates) based on detailed SEM examination, gave her an international reputation. As a teacher, she was noted for the care and effort that she put into stretching the minds of the brightest, while ensuring that even the weakest students had a chance. She was memorable for her dress sense (usually looking as if she had just come in from the field) and her sometimes colourful language.
The role of women in British Quaternary science
Authors: Hart J. K.
Published: October 2007

This study represents the first attempt to record the lives of women who have contributed to the field of Quaternary science. A list of women who lived or studied in the United Kingdom and Ireland was drawn up from suggestions provided by members of the British Quaternary Research Association (QRA). These were divided into three categories: pre-20th century, 20th century and retired. The lives of some of these women are described. It was particularly interesting that in the pre-20th-century and 20th-century categories, the number of geomorphologists was equal to the number of archaeologists/palaeoecologists. In addition, a study was undertaken of women physical geographers in British geography departments, which was compared with the results from a similar survey in 1996. In this way, recent changes (the last 10 years) in women in Quaternary science could also be evaluated. It was shown that although there was an increase in the number of women physical geography academics since 1996, the actual percentage of women had gone down, and although the percentage of women professors had risen, men's chance of reaching this position was still much higher. However, it is argued that the key element of women in Quaternary science, both today and in the past, is their enthusiasm for fieldwork, and it is this passion that enabled them to continue their studies whatever the current social conventions.
Great expectations: Florence Bascom (1842–1945) and the education of early US women geologists
Authors: Clary R. M. , Wandersee J. H.
Published: October 2007

Florence Bascom, the first woman to be awarded a PhD from Johns Hopkins University and the first professional US woman geologist, gained access through male connections into what was perceived to be a man's discipline. Her entrance into geology was not straightforward, but instead proceeded fairly erratically through an interwoven network of male acquaintances. Although Bascom's participation in professional circles garnered her acceptance by her male associates, it was her long academic career at Bryn Mawr College that made an impact on education and secured a supply of women in the discipline. Basing her instruction upon high expectations for herself and her students, innovative teaching techniques, and the pure joy she derived from geological investigation and geological thought, Bascom served as mentor to many in the succeeding generation of US women geologists. It was largely through Bascom's efforts that more women were able to pursue higher education in geology and excel at it in the first half of the 20th century.
The role of women in the history of geological studies in Ireland
Authors: Higgs Bettie , Jackson Patrick N. Wyse
Published: October 2007

During current research being carried out into the role of women in the history of geological study in Ireland, interesting social and cultural factors are emerging. A list of people who contributed to data gathering, and the unravelling of the complexity of Ireland's geology would characteristically contain only male names. Yet when one begins to look more closely, important roles were played by women. The story is one of women carrying out many and varied supporting roles, including stone-workers, illustrators, tutors, assistants, collaborators, wives, mothers, and later, curators, cartographers and technicians. From 1950 onwards, women begin to occupy professional roles as geologists, particularly in the Geological Survey of Ireland, but more slowly in academic circles. This paper concentrates on women now deceased, who paved the way for others, and only briefly indicates their legacy with selected examples leading to the present day.
Skin-derived microorgan autotransplantation as a novel approach for therapeutic angiogenesis
Authors: Voisine Pierre , Rosinberg Audrey , Wykrzykowska Joanna J. , Shamis Yulia , Wu Gui Fu , Appelbaum Evan , Li Jian , Sellke Frank W. , Pinto Duane , Gibson C. Michael , Mitrani Eduardo , Laham Roger J.
Published: October 2007

Despite promising preclinical results, transient single-factor-based therapeutic angiogenesis has shown no definitive benefits in clinical trials. The use of skin-derived microorgans (SMOs), capable of sustained expression of angiogenic factors and sustained viability with their cellular and extracellular elements, constitutes an attractive alternative. We sought to evaluate the efficacy of SMO implantation in a porcine model of chronic myocardial ischemia. Eighteen pigs underwent placement of an ameroid constrictor on the proximal circumflex artery. Three weeks later, split-thickness skin biopsies were harvested and pigs were randomized to lateral wall implantation of either 8 or 16 SMOs or blank injections. The procedure was safe and resulted in no adverse events. Three weeks after treatment, SMO implantation resulted in significant improvement of lateral wall perfusion during pacing, assessed by isotope-labeled microspheres [post- vs. pretreatment ratios of lateral/anterior wall blood flow were 1.31 ± 0.09 (SMOs) and 1.04 ± 0.06 (controls); P = 0.03]. No significant difference in angiographic scores was observed. Microvascular relaxation in response to VEGF was impaired in the ischemic territory of the control group but returned to normal after SMO implantation, indicating restoration of endothelial function. Molecular studies showed significant increases in VEGF and CD31 expression in the ischemic area of treated animals. Morphometric analysis showed increased neovascularization with SMO treatment. Autotransplantation of SMOs constitutes a novel approach for safe and effective therapeutic angiogenesis with improvement in perfusion, normalization of microvascular reactivity, and increased expression of VEGF and CD31.
Cardioprotection in female rats subjected to chronic volume overload: synergistic interaction of estrogen and phytoestrogens
Authors: Gardner Jason D. , Brower Gregory L. , Voloshenyuk Tetyana G. , Janicki Joseph S.
Published: October 2007

Intact female rats fed a high-phytoestrogen diet are protected against adverse left ventricular (LV) remodeling induced by chronic volume overload. We hypothesized that both phytoestrogens and ovarian hormones, particularly estrogen, are necessary for this dietary-induced cardioprotection. To test this hypothesis, eight groups of female rats were studied; rats were fed either a high-phytoestrogen (+phyto) or phytoestrogen-free diet. Groups included sham-operated rats, intact rats with fistula (Fist), ovariectomized rats with fistula (Fist-OX), and Fist-OX rats treated with estrogen (EST). Myocardial function and remodeling were assessed after 8 wk of volume overload using a blood-perfused isolated heart apparatus. Fist-OX rats developed significant ventricular dilatation and increased compliance vs. intact Fist rats, which were associated with a significant decrease in contractility. Estrogen treatment prevented pulmonary edema and attenuated LV hypertrophy and dilatation but did not maintain contractility. However, dietary phytoestrogens completely prevented LV dilatation in both the Fist+phyto and Fist-OX+EST+phyto groups but had no effect on LV remodeling in the Fist-OX+phyto group. Contractility was significantly greater in the estrogen-treated rats fed the phytoestrogen diet than in those treated with estrogen alone. Dietary phytoestrogens did not affect LV or uterine mass, serum estrogen, LV estrogen receptor expression, or cardiac function in sham animals. These data indicate that estrogen is not solely responsible for the cardioprotection exhibited by intact females and that phytoestrogens can work synergistically with ovarian hormones to attenuate ventricular remodeling induced by chronic volume overload in female rats.
Direct and reflexive effects of nitric oxide synthase inhibition on blood pressure
Authors: Wecht Jill M. , Weir Joseph P. , Goldstein David S. , Krothe-Petroff Annmarie , Spungen Ann M. , Holmes Courtney , Bauman William A.
Published: October 2007

Direct effects of vasoactive substances on blood pressure can be examined in individuals with tetraplegia due to disruption of descending spinal pathways to sympathetic preganglionic neurons, as cervical lesions interfere with baroreceptor reflex buffering of sympathetic outflow. In this study, we assessed effects of the nitric oxide synthase inhibitor nitro-l-arginine methyl ester (l-NAME) on mean arterial pressure, heart rate, and plasma norepinephrine concentrations in individuals with tetraplegia vs. effects shown in a neurologically intact control group. Seven individuals with tetraplegia and seven age-matched controls received, on separate visits and in the following order, placebo (30 ml normal saline) and 0.5, 1, 2, and 4 mg/kg l-NAME intravenously over 60 min. Supine hemodynamic data were collected, and blood was sampled at the end of each infusion and at 120, 180, and 240 min thereafter. l-NAME increased mean arterial pressure, and the relative increase was greater in the tetraplegia group than in the control group. Heart rate was reduced after l-NAME administration in both groups. l-NAME decreased plasma norepinephrine in the control group but not in the group with tetraplegia. These findings suggest that reflexive sympathoinhibition normally buffers the pressor response to nitric oxide synthase inhibition, an effect that is not evident in individuals with tetraplegia as a result of decentralized sympathetic vasomotor control.
Cerebral blood flow is increased during controlled ovarian stimulation
Authors: Nevo Ori , Soustiel Jean F. , Thaler Israel
Published: October 2007

Estrogen appears to enhance cerebral blood flow (CBF). An association between CBF and physiologically altered hormonal levels due to menstrual cycle, menopause, or exogenous manipulations such as ovariectomy or hormone replacement therapy has been demonstrated. The purpose of this study was to determine the association between ovarian stimulation and CBF in vivo by measuring blood flow in the internal carotid artery (ICA) after pituitary suppression and during controlled ovarian stimulation in women undergoing in vitro fertilization treatment cycles. ICA volume flows were measured by angle-independent dual-beam ultrasound Doppler in 12 women undergoing controlled ovarian stimulation. Measurements were performed after pituitary/ovarian suppression, in the late follicular phase, and at midluteal phase. Blood flow in the ICA increased by 22.2% and 32% in the late follicular and midluteal phases compared with the respective values obtained during ovarian suppression ( P < 0.0005 and P < 0.0001, respectively). There was a significant correlation between increments in estrogen levels and increments in CBF when the late follicular phase was compared with the ovarian suppression period ( r = 0.8, P < 0.001). Mean blood flow velocity significantly increased (by 15.7% and 16.9%, respectively) and cerebral vascular resistance significantly decreased (by 17.6% and 26.5%) during the late follicular and midluteal phases compared with respective measures during ovarian suppression. There was a significant correlation between an increase in estrogen levels and a decrease in cerebral vascular resistance when the late follicular phase was compared with the ovarian suppression period ( r = −0.6, P < 0.05). These changes imply sex hormone-associated intracranial vasodilation leading to increased CBF during controlled ovarian stimulation.
Ischemic preconditioning of the whole heart confers protection on subsequently isolated ventricular myocytes
Authors: Rodrigo Glenn C. , Samani Nilesh J.
Published: October 2007

Current cellular models of ischemic preconditioning (IPC) rely on inducing preconditioning in vitro and may not accurately represent complex pathways triggered by IPC in the intact heart. Here, we show that it is possible to precondition the intact heart and to subsequently isolate individual ventricular myocytes that retain the protection triggered by IPC. Myocytes isolated from Langendorff-perfused hearts preconditioned with three cycles of ischemia-reperfusion were exposed to metabolic inhibition and reenergization. Injury was assessed from induction of hypercontracture and loss of Ca2+ homeostasis and contractile function. IPC induced an immediate window of protection in isolated myocytes, with 64.3 ± 7.6% of IPC myocytes recovering Ca2+ homeostasis compared with 16.9 ± 2.4% of control myocytes ( P < 0.01). Similarly, 64.1 ± 5.9% of IPC myocytes recovered contractile function compared with 15.3 ± 2.2% of control myocytes ( P < 0.01). Protection was prevented by the presence of 0.5 mM 5-hydroxydecanoate during the preconditioning stimulus. This early protection disappeared after 6 h, but a second window of protection developed 24 h after preconditioning, with 54.9 ± 4.7% of preconditioned myocytes recovering Ca2+ homeostasis compared with 12.6 ± 2.9% of control myocytes ( P < 0.01). These data show that “true” IPC of the heart confers both windows of protection in the isolated myocytes, with a similar temporal relationship to in vivo preconditioning of the whole heart. The model should allow future studies in isolated cells of the protective mechanisms induced by true ischemia.
Principal strain changes precede ventricular wall thinning during transition to heart failure in a mouse model of dilated cardiomyopathy
Authors: Hankiewicz Janusz H. , Goldspink Paul H. , Buttrick Peter M. , Lewandowski E. Douglas
Published: October 2007

This study was performed to elucidate the relation between in vivo measurements of two-dimensional principal strains and the progression of left ventricle (LV) wall thinning during development of dilated cardiomyopathy in the protein kinase C-ε (PKC-ε) transgenic (TG) overexpressing mouse heart. Principal two-dimensional strains, E1 and E2, were determined in the LV wall of the anesthetized mouse using cardiac MRI tagging at 14.1 T. PKC-ε TG provided a model of pure dilated cardiomyopathy without evidence of hypertrophy (PKC-ε TG, n = 6). Ejection fraction, wall thickness, and principal strains were determined at 1-mo intervals in hearts of PKC-ε TG vs. age-matched, nontransgenic mice (NTG, n = 5) from age 6 to 13 mo. Through the study, PKC-ε TG displayed lower ejection fraction than NTG. At 7 mo, average principal strain E1 in PKC-ε TG hearts was lower compared with NTG (PKC-ε TG = 0.14 ± 0.03, NTG = 0.19 ± 0.03, P < 0.05). The greatest reductions in regional E1 occurred in the lateral segments. The principal strain E2 did not change significantly in either group. At 9 mo, LV wall thinning occurred in PKC-ε TG mice ( P < 0.01 vs. 8 mo) to 21% below values in NTG ( P < 0.001). Average E1 strain diverged between PKC-ε TG and NTG hearts by 25–43%. These E1 changes preceded LV wall thinning and predated the eventual transition from a compensated circumstance to the dilated phenotype. The findings indicate a near step function in E1 depression that precedes the onset of LV wall thinning and suggest E1 as a prognostic indicator of dilated cardiomyopathy.
PDE5A inhibition attenuates bleomycin-induced pulmonary fibrosis and pulmonary hypertension through inhibition of ROS generation and RhoA/Rho kinase activation
Authors: Hemnes Anna R. , Zaiman Ari , Champion Hunter C.
Published: October 2007

Pulmonary hypertension frequently complicates interstitial lung disease, where it is associated with a high mortality. Patients with this dual diagnosis often fare worse than those with pulmonary arterial hypertension (PAH) alone and respond poorly to standard PAH therapy, often dying of right ventricular (RV) failure. We hypothesize that nitric oxide synthase (NOS) uncoupling is important in the pathogenesis of interstitial lung disease-associated pulmonary hypertension, and this process can be abrogated by phosphodiesterase type 5 (PDE5) inhibition to improve pulmonary vascular remodeling and right ventricular function. Intratracheal bleomycin (4 U/kg) or saline control was administered to C57/BL6 mice after anesthesia. After recovery, animals were fed a diet of sildenafil (100 mg·kg−1·day−1) or vehicle for 2 wk when they underwent hemodynamic measurements, and tissues were harvested. Survival was reduced in animals treated with bleomycin compared with controls and was improved with sildenafil (100.0 vs. 73.7 vs. 84.2%, P < 0.05). RV/LV+S ratio was higher in bleomycin-alone mice with improvement in ratio when sildenafil was administered (33.00 ± 0.01% vs. 20.98 ± 0.01% P < 0.05). Histology showed less pulmonary vascular and RV fibrosis in the group cotreated with sildenafil. Bleomycin was associated with a marked increase in superoxide generation by DHE histological staining and luminol activity in both heart and lung. Treatment with sildenafil resulted in a concomitant reduction in superoxide levels in both heart and lung. These data demonstrate that PDE5 inhibition ameliorates RV hypertrophy and pulmonary fibrosis associated with intratracheal bleomycin in a manner that is associated with improved NOS coupling and a reduction in reactive oxygen species signaling.
Living Donor Liver Transplantation for Patients with HCC Exceeding the Milan Criteria: A Proposal of Expanded Criteria
Authors: Takada Yasutsugu , Ito Takashi , Ueda Mikiko , Sakamoto Seisuke , Haga Hironori , Maetani Yoji , Ogawa Kohei , Ogura Yasuhiro , Oike Fumitaka , Egawa Hiroto , Uemoto Shinji
Published: October 2007

Background: Optimal indications for living donor liver transplantation (LDLT) for patients with hepatocellular carcinoma (HCC) have yet not been established. The aim of the present study was to determine optimal criteria including categories outside the Milan criteria (MC) and still with a predictably good outcome. Patients and Methods: Between February 1999 and December 2007, 136 patients with HCC underwent LDLT. Based on preoperative imaging studies, 74 patients met the MC and 62 did not. Results: Overall patient survival rate at 5 years was 70%. Patients who exceeded MC but presented with ≤10 tumors and all ≤5 cm in diameter (n = 33) displayed similar 5-year recurrence rate to those within MC (7 vs. 10%). Based on the results of multivariate analysis of risk factors for recurrence, we defined new criteria as n ≤10 and all ≤5 cm and PIVKA-II ≤400 mAU/ml. The 5-year recurrence rate for the 83 patients who met the new criteria was significantly lower than for the 44 patients who exceeded them (5 vs. 61%, p < 0.0001). Similarly, patients who met the new criteria showed a significantly better 5-year survival rate (87 vs. 37%, p < 0.0001). Conclusion: The selection criteria may be safely extended up to n ≤10 and all ≤5 cm in diameter and PIVKA-II ≤400 mAU/ml with acceptable outcomes.
Hilar Mossy Cells Share Developmental Influences with Dentate Granule Neurons
Authors: Li Guangnan , Berger Omri , Han Szu-Min , Paredes Mercedes , Wu Ni-Chi , Pleasure Samuel J.
Published: October 2007

Mossy cells are the major class of excitatory neurons in the dentate hilus. Although mossy cells are involved in a range of physiological and pathological conditions, very little is known about their ontogeny. To gain insight into this issue, we first determined the developmental stage at which mossy cells can be reliably identified with the molecular markers calretinin and GluR2/3 and found that hilar mossy cells were first identifiable around the end of the 1st postnatal week. Birthdating studies combined with staining for these markers revealed that the appearance of mossy cells coincided with the first wave of dentate granule cell production during mid-gestation. Since mossy cells are born as the first granule cells are produced and it is believed that mossy cells originate from the neuroepithelium adjacent to the dentate progenitor zone, we examined to what extent the development of mossy cells is controlled by the same molecular pathways as that of granule cells. To do this, we analyzed the production of mossy cells in Lef1 and NeuroD mutant animals, in which granule cell production is disrupted during precursor proliferation or neuronal differentiation, respectively. The production of mossy cells was almost entirely lost in both mutants. Collectively, these data suggests that hilar mossy cells, unlike CA subfield pyramidal cells, are influenced by many of the same developmental cues as dentate granule cells.
The Effect of Binge Fetal Alcohol Exposure on the Number of Vasoactive Intestinal Peptide-Producing Neurons in Fetal Sheep Brain
Authors: Anderson David J. , Mondares Robin L. , Born Donald E. , Gleason Christine A.
Published: October 2007

Previously we demonstrated that fetal alcohol exposure attenuates hypoxic cerebral vasodilation in fetal and neonatal sheep. One mechanism may be altered expression of brain vasoactive substances. We hypothesized that early fetal alcohol exposure alters the number of fetal neurons expressing vasoactive intestinal peptide (VIP), a potent cerebral vasodilator. Thirteen pregnant ewes received daily i.v. infusions of alcohol (1.5 g/kg) or saline on days 30–54 of gestation (term = 145 days). Fourteen fetal brains (6 alcohol-exposed, 8 saline control) were obtained on gestational day 126. Using unbiased stereology, we counted immunohistochemically-labeled VIP neurons in one half of each forebrain with an optical fractionator. The total NeuN-labeled neurons were similarly counted. Alcohol-exposed fetal sheep brains had fewer VIP-immunopositive neurons per hemisphere, 14.6 × 106, compared to saline controls, 19.8 × 106. The total neuron number was not different, 1.19 × 109 versus 1.23 × 109 respectively, indicating a selective decrease in VIP neurons as a result of alcohol exposure. In sheep, alcohol exposure early in gestation is associated with fewer VIP-producing neurons later in gestation compared to saline controls; therefore, alcohol-related changes in the number of VIP-expressing neurons may be responsible in part for the attenuated hypoxic cerebral vasodilation described in fetal and neonatal sheep exposed to alcohol earlier in gestation.
Three-Dimensional High-Resolution Diffusion Tensor Imaging and Tractography of the Developing Rabbit Brain
Authors: D’Arceuil Helen , Liu Christina , Levitt Pat , Thompson Barbara , Kosofsky Barry , de Crespigny Alex
Published: October 2007

Diffusion tensor imaging (DTI) is sensitive to structural ordering in brain tissue particularly in the white matter tracts. Diffusion anisotropy changes with disease and also with neural development. We used high-resolution DTI of fixed rabbit brains to study developmental changes in regional diffusion anisotropy and white matter fiber tract development. Imaging was performed on a 4.7-tesla Bruker Biospec Avance scanner using custom-built solenoid coils and DTI was performed at various postnatal ages. Trace apparent diffusion coefficient, fractional diffusion anisotropy maps and fiber tracts were generated and compared across the ages. The brain was highly anisotropic at birth and white matter anisotropy increased with age. Regional DTI tractography of the internal capsule showed refinement in regional tract architecture with maturation. Interestingly, brains with congenital deficiencies of the callosal commissure showed selectively strikingly different fiber architecture compared to age-matched brains. There was also some evidence of subcortical to cortical fiber connectivity. DTI tractography of the anterior and posterior limbs of the internal capsule showed reproducibly coherent fiber tracts corresponding to known corticospinal and corticobulbar tract anatomy. There was some minor interanimal tract variability, but there was remarkable similarity between the tracts in all animals. Therefore, ex vivo DTI tractography is a potentially powerful tool for neuroscience investigations and may also reveal effects (such as fiber tract pruning during development) which may be important targets for in vivo human studies.
Differential Economic Impacts of Corporate Responsibility Issues
Authors: Lankoski Leena
Published: October 2007

The study examined whether there are systematic differences in the economic impacts of different corporate responsibility issues and found that the content of corporate responsibility does have an effect on economic impact. Economic impacts were more positive for corporate responsibility issues that reduce negative externalities than for those that generate positive externalities and more positive as well as for issues whose outcome benefits market stakeholders rather than nonmarket stakeholders.
A Social Movement Perspective of Stakeholder Collective Action and Influence
Authors: King Brayden
Published: October 2007

This article provides a social movement theory—based explanation for the emergence and influence of corporate stakeholders. The author argues that stakeholder influence originates in the collective action of potential stakeholders. Collective action binds individual stakeholders together, assists in the formation of a common identity and interests, and provides the means for stakeholder strategic action. The author suggests three main factors that explain the emergence of stakeholder collective action and its consequent influence: mobilizing structures, corporate opportunities, and framing processes. By focusing more on the collective action necessary for stakeholder influence, we also gain a better understanding of how negotiation processes might unfold between stakeholders and corporate decision makers.