bluuebunny/crossref_metadata_2025 huggingface dataset:
Inhibition Mechanisms of Bioflavonoids Extracted from the Bark of Pinus maritima on the Expression of Proinflammatory Cytokines
Authors: Cho Kyung‐Joo , Yun Chang‐Hyun , Packer Lester , Chunga An‐Sik
Published: July 2010

Abstract:The effect of bioflavonoids extracted from the bark ofPinus maritima, Pycnogenol (PYC), on gene expression of the proinflammatory cytokines interleukin‐1β (IL‐1β) and interleukin‐2 (IL‐2) were investigated in RAW 264.7 cells and Jurkat E6.1 cells, respectively. PYC exerted strong scavenging activities against reactive oxygen species (ROS) generated by H2O2in RAW 264.7.In situELISA, immunoblot analysis, and competitive RT‐PCR demonstrated that pretreatment of LPS‐stimulated RAW 264.7 cells with PYC dose‐dependently reduced both the production of IL‐1β and its mRNA levels. Furthermore, in the same cells, PYC blocked the activation of nuclear factor κB (NF‐κB) and activator protein‐1 (AP‐1), two major transcription factors centrally involved in IL‐1β gene expression. Concordantly, pretreatment of the cells with PYC abolished the LPS‐induced IκB degradation. We also investigated the effect of PYC on IL‐2 gene expression in phorbol 12‐myristate 13acetate plus ionomycin (PMA/Io)‐stimulated human T‐cell line Jurkat E6.1. PYC inhibited the PMA/Io‐induced IL‐2 mRNA expression. However, as demonstrated in a reporter gene assay system, the mechanism of IL‐2 gene transcriptional regulation by PYC was different from the regulation of IL‐1β. PYC inhibited both NF‐AT and AP‐1 chloramphenicol acetyltransferase (CAT) activities in transiently transfected Jurkat E6.1, but not NF‐κB CAT activity. We also found that PYC can destabilize PMA/Io‐induced IL‐2 mRNA by posttranscriptional regulation. All these results suggest that bioflavonids can be useful therapeutic agents in treating many inflammatory, autoimmune, and cardiovascular diseases based on its diverse action mechanisms.
Nutrition Interventions in Aging and Age‐Associated Disease
Authors: Meydani Mohsen
Published: July 2010

Abstract: The nutritional status and needs of elderly people are associated with age‐related biological and often socioeconomic changes. Decreased food intake, a sedentary lifestyle, and reduced energy expenditure in older adults altogether become critical risk factors for malnutrition, especially protein and micronutrients. Surveys indicate that the elderly are particularly at risk for marginal deficiency of vitamins and trace elements. Changes in bodily functions, together with the malnutrition associated with advancing age, increase the risk of developing a number of age‐related diseases. Chronic conditions pose difficulties for the elderly in carrying out the activities of daily living and may increase the requirements for certain nutrients due to changes in absorptive and metabolic capacity. Free radicals and oxidative stress have been recognized as important factors in the biology of aging and of many age‐associated degenerative diseases. In this regard, modulation of oxidative stress by calorie restriction, as demonstrated in animal models, is suggested as one mechanism to slow the aging process and the decline of body functions. Therefore, dietary components with antioxidant activity have received particular attention because of their potential role in modulating oxidative stress associated with aging and chronic conditions. Several studies have indicated potential roles for dietary antioxidants in the reduction of degenerative disease such as vascular dementia, cardiovascular disease, and cancer. In support of epidemiological studies, our recent studies indicate that the antioxidant properties of vitamin E and polyphenols present in green tea may contribute to reducing the risk of cardiovascular disease, in part by reducing the susceptibility of low density lipoproteins to oxidation, decreasing the vascular endothelial cell expression of pro‐inflammatory cytokines, and decreasing the expression of adhesion molecules and monocyte adhesion. Recently, we also demonstrated that these dietary antioxidants may have a preventive role in cancer, potentially through the suppression of angiogenesis by inhibiting interleukin‐8 production and the cell junction molecule VE‐cadherin. These findings concur with epidemiologic, clinical, and animal studies suggesting that the consumption of green tea and vitamin E is associated with a reduced risk of cardiovascular disease and cancer, the leading causes of morbidity and mortality among the elderly.
A New Function of Green Tea: Prevention of Lifestyle‐related Diseases
Authors: Sueoka Naoko , Suganuma Masami , Sueoka Eisaburo , Okabe Sachiko , Matsuyama Satoru , Imai Kazue , Nakachi Kei , Fujiki Hirota
Published: July 2010

Abstract: In the normal human life span, there occur lifestyle‐related diseases that may be preventable with nontoxic agents. This paper deals with the preventive activity of green tea in some lifestyle‐related diseases. Green tea is one of the most practical cancer preventives, as we have shown in various in vitro and in vivo experiments, along with epidemiological studies. Among various biological effects of green tea, we have focused on its inhibitory effect on TNF‐α gene expression mediated through inhibition of NF‐κB and AP‐1 activation. Based on our recent results with TNF‐α‐deficient mice, TNF‐α is an endogenous tumor promoter. TNF‐α is also known to be a central mediator in chronic inflammatory diseases such as rheumatoid arthritis and multiple sclerosis. We therefore hypothesized that green tea might be a preventive agent for chronic inflammatory diseases. To test this hypothesis, TNF‐α transgenic mice, which overexpress TNF‐α only in the lungs, were examined. The TNF‐α transgenic mouse is an animal model of human idiopathic pulmonary fibrosis which also frequently develops lung cancer. Expressions of TNF‐α and IL‐6 were inhibited in the lungs of these mice after treatment with green tea in drinking water for 4 months. In addition, judging from the results of a prospective cohort study in Saitama Prefecture, Japan, green tea helps to prevent cardiovascular disease. In this study, a decreased relative risk of death from cardiovascular disease was found for people consuming over 10 cups of green tea a day, and green tea also had life‐prolonging effects on cumulative survival. These data suggest that green tea has preventive effects on both chronic inflammatory diseases and lifestyle‐related diseases (including cardiovascular disease and cancer), resulting in prolongation of life span.
Caloric Restriction in Primates
Authors: Lane M. A. , Black A. , Handy A. , Tilmont E. M. , Ingram D. K. , Roth G. S.
Published: July 2010

Abstract:Caloric restriction (CR) remains the only nongenetic intervention that reproducibly extends mean and maximal life span in short‐lived mammalian species. This nutritional intervention also delays the onset, or slows the progression, of many age‐related disease processes. The diverse effects of CR have been demonstrated many hundreds of times in laboratory rodents and other short‐lived species, such as rotifers, water fleas, fish, spiders, and hamsters. Until recently, the effects of CR in longer‐lived species, more closely related to humans, remained unknown. Long‐term studies of aging in nonhuman primates undergoing CR have been underway at the National Institute on Aging (NIA) and the University of Wisconsin‐Madison (UW) for over a decade. A number of reports from the NIA and UW colonies have shown that monkeys on CR exhibit nearly identical physiological responses as reported in laboratory rodents. Studies of various markers related to age‐related diseases suggest that CR will prevent or delay the onset of cardiovascular disease, diabetes, and perhaps cancer, and preliminary data indicate that mortality due to these and other age‐associated diseases may also be reduced in monkeys on CR, compared to controls. Conclusive evidence showing that CR extends life span in primates is not presently available; however, the emerging data from the ongoing primate studies strengthens the possibility that the diverse beneficial effects of CR on aging in rodents will also apply to nonhuman primates and perhaps ultimately to humans.
Tonal Cognition
Authors: KRUMHANSL CAROL L. , TOIVIAINEN PETRI
Published: July 2010

Abstract: This article presents a self‐organizing map (SOM) neural network model of tonality based on experimentally quantified tonal hierarchies. A toroidal representation of key distances is recovered in which keys are located near their neighbors on the circle of fifths, and both parallel and relative major/minor key pairs are proximal. The map is used to represent dynamic changes in the sense of key as cues to key become more or less clear and modulations occur. Two models, one using tone distributions and the other using tone transitions, are proposed for key‐finding. The tone transition model takes both pitch and temporal distance between tones into account. Both models produce results highly comparable to those of musically trained listeners, who performed a probe tone task for ten nine‐chord sequences. A distributed mapping of tonality is used to visualize activation patterns that change over time. The location and spread of this activation pattern is similar for experimental results and the key‐finding model.
Representational Cortex in Musicians
Authors: PANTEV C. , ENGELIEN A. , CANDIA V. , ELBERT T.
Published: July 2010

Abstract: The lifelong ability to adapt to environmental needs is based on the capacity of the central nervous system for plastic alterations. In a series of neurophysiological experiments, we studied the impact of music and musical training in musicians on the specific functional organization in auditory and somatosensory representational cortex. In one such study, subjects listened to music from which one specific spectral frequency was removed. This led to rapid and reversible adaptation of neuronal responses in auditory cortex. Further experimental evidence demonstrated that long years of practice and training by professional musicians to enable them to reach their capacity is associated with enlarged cortical representations in the somatosensory and auditory domains. This tuning of neuronal representations was specifically observed for musical tones and was absent when pure sinusoidal tones were used as stimuli. In the somatosensory cortex, plastic changes proved to be specific for the fingers frequently used and stimulated. These changes were not detected in the fingers of the hand that were not involved in playing the particular instrument. Neuroplastic alterations also may be driven into a domain where they may become maladaptive. The clinical syndrome of focal hand dystonia that may occur in musicians who engage in forceful practice may be one such consequence. We will discuss the possibilities of reversing maladaptive responses leading to the successful treatment of focal hand dystonia, which relies on basic research about cortical reorganization. This example elucidates how neuroscientific progress can guide the development of practice guidelines and therapeutic measures for the benefit of professional musicians.
Music and Nonmusical Abilities
Authors: SCHELLENBERG E. GLENN
Published: July 2010

Abstract: Reports that exposure to music causes benefits in nonmusical domains have received widespread attention in the mainstream media. Such reports have also influenced public policy. The so‐called “Mozart effect” actually refers to two relatively distinct phenomena. One concerns short‐term increases in spatial abilities that are said to occur from listening to music composed by Mozart. The other refers to the possibility that formal training in music yields nonmusical benefits. A review of the relevant findings indicates that the short‐term effect is small and unreliable. Moreover, when it is evident, it can be explained by between‐condition differences in the listener's mood or levels of cognitive arousal. By contrast, the effect of music lessons on nonmusical aspects of cognitive development is still an open question. Several studies have reported positive associations between formal music lessons and abilities in nonmusical (e.g., linguistic, mathematical, and spatial) domains. Nonetheless, compelling evidence for a causal link remains elusive.
Adults with ADHD
Authors: WENDER PAUL H. , WOLF LORRAINE E. , WASSERSTEIN JEANETTE
Published: July 2010

Abstract: Attention‐Deficit Hyperactivity Disorder (ADHD) is a common, genetically transmitted neurological disorder, with onset in childhood, probably mediated by decreased brain dopaminergic functioning. The first author was one of the earliest to describe the persistence of symptoms into adulthood. Prevalence and natural history data suggest that of the 3 to 10% of children diagnosed with ADHD, one‐ to two‐thirds (somewhere between 1 and 6% of the general population) continue to manifest appreciable ADHD symptoms into adult life. This paper describes how ADHD in adults can be readily diagnosed and treated, despite resembling or coexisting with other psychiatric disorders. The Wender Utah diagnostic criteria address adult characteristics of the disorder. Informant and patient interviews and rating scales are used to determine the psychiatric status of the patient as a child, make a retroactive diagnosis of childhood ADHD, and establish the current diagnosis of the adult. Stringent diagnosis is key to determining effective treatment. Dopamine agonist stimulant medications appear to be the most effective in treating ADHD. About 60% of patients receiving stimulant medication showed moderate‐to‐marked improvement, as compared with 10% of those receiving placebo. The core symptoms of hyperactivity, inattention, mood lability, temper, disorganization, stress sensitivity, and impulsivity have been shown to respond to treatment with stimulant medications. Non‐dopaminergic medications, such as the tricyclic antidepressants and SSRIs have generally not been useful in adults with ADHD in the absence of depression or dysthymia. Pemoline is no longer appoved for use in these patients, despite early favorable reports. Appropriate management of adult patients with ADHD is multimodal. Psychoeducation, counseling, supportive problem‐directed therapy, behavioral intervention, coaching, cognitive remediation, and couples and family therapy are useful adjuncts to medication management. Concurrent supportive psychosocial treatment or polypharmacy may be useful in treating the adult with comorbid ADHD.
Continuous Performance Tests Are Sensitive to ADHD in Adults but Lack Specificity
Authors: RICCIO CYNTHIA A. , REYNOLDS CECIL R.
Published: July 2010

Abstract: Historically, the focus for Attention Deficit Hyperactivity Disorder (ADHD) has been on children, with considerable research and many opinions available in this area. More recently, the focus has been expanded to include ADHD in adults. Assessment of ADHD in adults is complicated by the high rate of co‐occurring disorders as well as symptom overlap with a number of disorders. One popular family of measures for the assessment of attention and executive control is the continuous performance test (CPT). A review of the available research on CPTs reveals that they are quite sensitive to CNS dysfunction. This is both a strength and a limitation of CPTs in that multiple disorders can result in impaired performance on a CPT. The high sensitivity of CPTs is further complicated by the multiple variations of CPTs available, some of which may be more sensitive or demonstrate better specificity to ADHD in adults than others. If CPTs are to be used clinically, further research will be needed to answer the questions raised by this review.
Improving Attention and Managing Attentional Problems
Authors: SOHLBERG McKAY MOORE , MATEER CATHERINE A.
Published: July 2010

Abstract: Research and clinical experience in the field of brain injury rehabilitation have focused quite extensively on the need and potential to retrain attentional skills that are commonly affected by acquired brain injury. Four approaches to managing attention impairments that have emerged from this literature include attention process training, training use of strategies and environmental support, training use of external aids, and the provision of psychosocial support. Most often, several of these will be used in combination. For example, a therapy regimen might include attention process training emphasizing specific components of attention (e.g., sustained attention), in conjunction with training in pacing techniques, and psychosocial support, where the client keeps behavioral logs and discusses insights gained from tracking attention successes and attention lapses. Although there are as yet little data with regard to the effectiveness of these approaches in adults with developmental disorders of attention, there is a growing literature suggesting they may be effective in children and adolescents with ADHD. Further investigation of the application of such techniques in adults with a wide variety of attention disorders, including developmental disorders, would be valuable.
College Students with ADHD and Other Hidden Disabilities
Authors: WOLF LORRAINE E.
Published: July 2010

Abstract:Nearly 25 years of special education law have enabled many qualified students with disabilities to graduate from college preparatory high school programs and enter institutes of higher education. The Americans with Disabilities Act enacted by Congress in 1990, the Individuals with Disabilities Education Act of 1975, and Section 504 of the Rehabilition Act of 1973 all mandate special education services for students with disabilities. A parallel nationwide rise is being reported in the numbers of students with disabilities on college campuses. The greatest increase is seen in students with so‐called hidden disabilities such as learning disabilities, ADHD, and psychiatric disabilities. These students face a number of obstacles once they are admitted to college. Many factors, some intrinsic to the student and others extrinsic to the campus, moderate success in higher education. Overlapping or multiple diagnoses, psychological distress, poor social and interpersonal skills, persisting cognitive deficits (especially in the area of executive functioning), and alcohol abuse are important factors that must be understood as institutions of higher education strive to promote access and provide effective support services on their campuses.
When to Hospitalize Patients at Risk for Suicide
Authors: Hirschfeld Robert M.A.
Published: July 2010

Abstract:The decision to hospitalize patients at imminent risk for suicide requires careful assessment of risk factors, including sociodemographic, psychiatric, general medical, and mental status considerations. Assessment of these risk factors is essential and can usually be accomplished in a straightforward manner, although clinical obstacles sometimes make assessment more difficult. Key issues regarding imminent suicide risk are intent and means, severity of psychiatric illness, the presence of psychosis or hopelessness, lack of personal resources, and older age among men. Once the decision to hospitalize is made, reasonable care should be taken to assure that the patient is transported to the treating hospital safely and is not left alone. On arrival at the hospital, the patient should be closely monitored, and reasonable precautions must be taken to assure the patient's safety at all times, especially during the first few days. Proper assessment, monitoring, and treatment of patients at imminent risk for suicide save lives. A person who is determined to kill himself/herself will probably prevail despite our best efforts. However, most people who are imminently suicidal at one time will feel very differently at some later time.
Firearms and Suicide
Authors: Brent David A.
Published: July 2010

Abstract: The evidence linking firearms in the home to risk for suicide is reviewed. These data come from epidemiological, case‐control, quasiexperimental, and prospective studies. The convergent finding from this wide range of studies is that there is a strong relationship between firearms in the home and risk for suicide, most firmly established in the United States.
Sensitization Studies in Chemically Intolerant Individuals: Implications for Individual Difference Research
Authors: Bell Iris R. , Baldwin Carol M. , Schwartz Gary E. R.
Published: July 2010

Abstract:Chemical intolerance (CI) is an individual difference trait in which persons report feeling ill in multiple physiological systems from low levels of a wide range of chemically unrelated environmental substances. This paper discusses the neural sensitization model for progressive host amplification of polysymptomatic responses elicited by chemical exposures following an initiating event. The sensitization model accommodates hypotheses for initiating and eliciting CI in human populations that involve both environmental chemicals and physical or psychological stressors. Recent studies in this laboratory have demonstrated sensitization in individuals with CI over repeated sessions for dependent variables such as electroencephalographic (EEG) activity and diastolic blood pressure. Psychological distress variables alone do not explain these findings. Individuals with CI and/or vulnerability to sensitization share specific characteristics, for example, female gender, certain genetic background (offspring of alcohol‐preferring parents), and personal preference for high sugar/carbohydrate intake. Overall, the data suggest that the 15‐30% of the general population who report heightened CI are highly sensitizable. Sensitizability may serve an adaptive, sentinel function in threatening environments with poor signal‐to‐noise ratios. However, as sensitization gradually shifts operating set points of physiological systems out of the normal range in response to allostatic load, this process may contribute to the development of chronic, polysymptomatic health conditions such as multiple chemical sensitivity and/or fibromyalgia. Individual response specificity and stereotypy rather than toxicant properties may determine which types of central, autonomic, and/or peripheral nervous system dysfunctions manifest at subclinical and clinical levels.
Environmental Risks and Public Health
Authors: Goldstein Bernard D.
Published: July 2010

Abstract: There are currently a number of initiatives aimed at considering and redefining the role of environmental health. These include an effort under the auspices of the Institute of Medicine Roundtable on Environmental Health and another under the auspices of the American Schools of Public Health. Both will result in conferences to be held in the same month of the New York Academy of Sciences (NYAS) conference on “The Role of Neural Plasticity in Chemical Intolerance”, for which this paper is being prepared. This questioning of our definition and of our approach to the field of environmental health is an instructive background on which to consider the issue of environmental risks and public health—the topic given to me by the organizers of the NYAS conference. My approach will be to touch on those issues related to the nervous system and to unexplained symptoms in keeping with the subject of the conference, as well as to discuss some of the broader issues surrounding environmental health.
Representation of Acute and Persistent Pain in the Human CNS: Potential Implications for Chemical Intolerance
Authors: Rainville Pierre , Bushnell M. Catherine , Duncan Gary H.
Published: July 2010

Abstract: The study of pain may be relevant to the study of chemical intolerance (CI) in many ways. Pain is often reported as a symptom of CI and it is defined as a subjective experience similar to many other symptoms of CI, making its objectification difficult. Furthermore, the CNS plastic changes that underlie the development of persistent pain states and abnormal pain responses may share some similarities with those involved in the sensitization to environmental chemicals. Functional brain imaging studies in humans demonstrate that acute pain evoked by nociceptive stimulation is accompanied by the activation of a widely distributed network of cerebral structures, including the thalamus and the somatosensory, insular, and anterior cingulate cortices. Abnormal activity within these regions has been associated with the experience of pain following damage to the peripheral or central nervous system (neuropathic pain) in a number of clinical populations. In normal individuals, activity within this network is correlated with subjective pain perception, is highly modifiable by cognitive interventions such as hypnosis and attention, and has been associated with emotions. Other cognitive mediators such as expectations can also produce robust changes in pain perception (e.g., in placebo analgesia). These effects likely depend on both higher‐order cerebral structures and descending mechanisms modulating spinal nociceptive activity. These psychological processes can be solicited to reduce clinical pain and we speculate that they may further attenuate or promote central mechanisms involved in the transition from acute to persistent pain states. The investigation of central determinants of subjective experience is essential to assess the possibility that higher‐order brain/psychological processes modulate and/or mediate the development of persistent pain states. These factors may contribute to the development of symptoms in CI.
Pavlovian Conditioning of Emotional Responses to Olfactory and Contextual Stimuli
Authors: Otto Tim , Giardino Nicholas D.
Published: July 2010

Abstract: Chemical intolerance (CI) in humans is a poorly understood phenomenon of uncertain etiology, seemingly influenced by multiple factors both within and between affected individuals. Several authors have suggested that the development of CI in some individuals may be due, at least in part, to Pavlovian conditioning processes in which the expression of overt symptoms to certain substances reflects classically conditioned responses to previously neutral olfactory and contextual stimuli. In this paper, we describe the potential relationship between olfactory and contextual conditioning in experimental animals and the development and expression of CI in humans. Furthermore, as significant advances have been made in delineating the brain areas that underlie these learned responses, we also review recent research on the contributions of the amygdala and perirhinal cortical region to olfactory and contextual fear conditioning.
Heat Transfer near Turbine Nozzle Endwall
Authors: CHYU MINKING K.
Published: July 2010

Abstract: This paper gives an overview and reviews recent findings concerning turbine endwall cooling in the literature. The text below begins with a brief discussion of the secondary flows and heat transfer around cascade endwall. This will be followed by a review of recent developments in cooling concepts and related heat transfer results. Key topics include: film cooling, upstream bleeding, endwall contouring, and leakage through component interfaces.
Turbulence Modeling in Simulation of Gas‐Turbine Flow and Heat Transfer
Authors: BRERETON G. , SHIH T. I‐P.
Published: July 2010

Abstract: The popular k‐ε type two‐equation turbulence models, which are calibrated by experimental data from simple shear flows, are analyzed for their ability to predict flows involving shear and an extra strain ‐ flow with shear and rotation and flow with shear and streamline curvature. The analysis is based on comparisons between model predictions and those from measurements and large‐eddy simulations of homogenous flows involving shear and an extra strain, either from rotation or from streamline curvature. Parameters are identified, which show the conditions under which performance of k‐ε type models can be expected to be poor.
Recent Developments in Turbine Blade Internal Cooling
Authors: HAN JE‐CHIN , DUTTA SANDIP
Published: July 2010

Abstract: This paper focuses on turbine blade internal cooling. Internal cooling is achieved by passing the coolant through several rib‐enhanced serpentine passages inside the blade and extracting the heat from the outside of the blades. Both jet impingement and pin‐fin‐cooling are also used as a method of internal cooling. In the past number of years there has been considerable progress in turbine blade internal cooling research and this paper is limited to reviewing a few selected publications to reflect recent developments in turbine blade internal cooling.
A Conjugate Heat Transfer Procedure for Gas Turbine Blades
Authors: CROCE GIULIO
Published: July 2010

Abstract: A conjugate heat transfer procedure, allowing for the use of different solvers on the solid and fluid domain(s), is presented. Information exchange between solid and fluid solution is limited to boundary condition values, and this exchange is carried out at any pseudo‐time step. Global convergence rate of the procedure is, thus, of the same order of magnitude of stand‐alone computations.
Contribution of Heat Transfer to Turbine Blades and Vanes for High Temperature Industrial Gas Turbines Part 1: Film Cooling
Authors: TAKEISHI KEN‐ICHIRO , AOKI SUNAO
Published: July 2010

Abstract:This paper deals with the contribution of heat transfer to increase the turbine inlet temperature of industrial gas turbines in order to attain efficient and environmentally benign engines. High efficiency film cooling, in the form of shaped film cooling and full coverage film cooling, is one of the most important cooling technologies. Corresponding heat transfer tests to optimize the film cooling effectiveness are shown and discussed in this first part of the contribution.
Film Cooling: Case Of Double Rows Of Staggered Jets
Authors: DORIGNAC E. , VULLIERME J.J. , NOIRAULT P. , FOUCAULT E. , BOUSGARBIÈS J.L.
Published: July 2010

Abstract: An experimental investigation of film cooling of a wall in a case of double rows of staggered hot jets (65°C) in an ambient air flow. The wall is heated at a temperature value between the one of the jets and the one of the main flow. Experiments have been carried out for different injection rates, the main flow velocity is maintained at 32 m/s. Association of the measures of temperature profiles by cold wire and the measures of wall temperature by infrared thermography allows us to describe the behaviour of the flows and to propose the best injection which assures a good cooling of the plate.
FILM COOLING PERFORMANCE ON CURVED WALLS WITH COMPOUND ANGLE HOLE CONFIGURATION
Authors: Chen Ping‐Hei , Hung Min‐Sheng , Ding Pei‐Pei
Published: July 2010

Abstract: In order to explore the effect of compound angle holes on film cooling over a convex wall and a concave wall, the present study adopts the transient liquid crystal thermography for conducting the film cooling measurement on simple hole and expanded‐hole configurations. Two compound angles of 0 and 45 deg are tested at an elevated mainstream turbulence condition (Tu) of 3.8 %. The test pieces have the different radius of curvature (2r/D) of 92.5 on convex and 86.5 on concave, and the same pitch to diameter ratio (P/D) of 3 on both convex and concave walls. All measurements were conducted under the mainstream Reynolds number (Red) of 1700 on convex and 2300 on concave with the density ratio between coolant and mainstream (ρc/ρm) of 0.98. In current study, the effect of blowing ratio (M) on film cooling performance is investigated by varying the range of blowing ratio from 0.5 and 2.0. The present measured results show that the forward‐expanded hole injection provides better surface protection than the simple hole injection. As far as the injection angle is concerned, compound angle injection provides higher film effectiveness than simple angle injection. However, the forward‐expanded hole injection (β= 0°) has the best performance on both convex and concave surfaces.
Comparison between two models of cooling surfaces using blowing
Authors: MATHELIN L. , BATAILLE F. , LALLEMAND A.
Published: July 2010

Abstract: To protect surfaces against high temperatures, the blowing through a porous material is studied. The geometry is that of a circular cylinder in cross‐flow and the effectiveness of the blowing for the thermal protection is numerically investigated. Two models are developed for the blowing simulation and comparisons are made with experimental data obtained in a heated wind‐tunnel. It is shown that the blowing strongly affects the dynamical and thermal profiles over the surface, thickening the boundary layers and decreasing the external transfer coefficients. It results in a lower viscous drag and thermal stress. The wall temperature dramatically decreases with blowing and the heat flux is also affected.
Verifying Heat Transfer Analysis of High Pressure Cooled Turbine Blades and Disk
Authors: YAMAWAKI SHIGEMICHI
Published: July 2010

Abstract: To demonstrate cooling and heat transfer technology, a core engine test was conducted with a turbine inlet temperature 1700°C. Measurement data were compared with predictions for a vane, a blade, and a disk. Measured cooling effectiveness of the blade and the vane agreed well with predictions. CFD analysis was carried out for verification of the heat transfer coefficient which was adopted from a heat conduction analysis over the disk. The CFD model including bolt heads showed better results than an axi‐symmetric model.
COMPUTATION OF FLOW AND HEAT TRANSFER IN ROTATING CAVITIES WITH PERIPHERAL FLOW OF COOLING AIR
Authors: KILIÇ Muhsin
Published: July 2010

Abstract: Numerical solutions of the Navier‐Stokes equations have been used to model the flow and the heat transfer that occurs in the internal cooling‐air systems of gas turbines. Computations are performed to study the effect of gap ratio, Reynolds number and the mass flow rate on the flow and the heat transfer structure inside isothermal and heated rotating cavities with peripheral flow of cooling air. Computations are compared with some of the recent experimental work on flow and heat transfer in rotating‐cavities. The agreement between the computed and the available experimental data is reasonably good.
Genetic and Environmental Influences on Exceptional Longevity and the AGE Nomogram
Authors: PERLS THOMAS
Published: July 2010

To live beyond the octogenarian years, population and molecular genetic studies of centenarian sibships indicate that genetic factors play an increasingly important role as the limit of life span is approached. These factors are likely to influence basic mechanisms of aging that in turn broadly influence susceptibility to age‐related illnesses. Lacking genetic variations that predispose to disease as well as having variations that confer disease resistance (longevity enabling genes) are probably both important to achieving exceptional old age. The AGE (aging, genetics, environment) nomogram is introduced as an illustrative construct for understanding the influence of environmental and genetic factors on survival to various ages, depending on variations in the hypothesized relative importance of genes and environment to longevity. The rapid rise in the incidence of centenarians could indicate that many more people than we originally thought have the optimal set of genetic factors necessary to get to 100 and beyond. Recent studies indicate the likelihood that such factors will be elucidated in the near future.
Pigments in Aging: An Overview
Authors: PORTA EDUARDO A.
Published: July 2010

Although during the normal aging process there are numerous pigmentary changes, the best recognized are those of melanin and lipofuscin. Melanin may increase (e.g., age spots, senile lentigo, or melanosis coli) or decrease (e.g., graying of hair or ocular melanin) with age, while lipofuscin (also called age pigment) always increases with age. In fact, the time‐dependent accumulation of lipofuscin in lysosomes of postmitotic cells and some stable cells is the most consistent and phylogenetically constant morphologic change of aging. This pigment displays a typical autofluorescence (Ex: ∼440; Em: ∼600 nm), sudanophilia, argyrophilia, PAS positiveness, and acid fastness. Advances on its biogenesis, composition, evolution, and lysosomal degradation have been hampered by the persistent confusion between lipofuscin and the large family of ceroid pigments found in a variety of pathological conditions, as evidenced by the frequent use of the hybrid term lipofuscin/ceroid by investigators mainly working with in vitro systems of disputable relevance to in vivo lipofuscinogenesis. While lipofuscin and ceroid pigments may share some of their physicochemical properties at one moment or another in their evolutions, these pigments have different tissue distribution, rates of accumulation, origin of their precursors, and lectin binding affinities. Although it is widely believed that lipofuscin is a marker of oxidative stress, and that it can be, therefore, modified by antioxidants and prooxidants, these assumptions are mainly based on in vitro experiments and are not generally supported by in vivo studies. Another common misconception is the belief that lipofuscin can be extracted from tissues by lipid solvents and measured spectrofluorometrically. These and other disturbing problems are reviewed and discussed in this presentation.
Fruit Polyphenolics and Brain Aging
Authors: GALLI RACHEL L. , SHUKITT‐HALE BARBARA , YOUDIM KURESH A. , JOSEPH JAMES A.
Published: July 2010

Nutritional interventions, in this case, increasing dietary intake of fruits and vegetables, can retard and even reverse age‐related declines in brain function and in cognitive and motor performance in rats. Our lab has shown that as Fischer 344 rats age their brains are increasingly vulnerable to oxidative stress. Dietary supplementation with fruit or vegetable extracts high in antioxidants (e.g., blueberry, BB, spinach, respectively) can decrease this vulnerability to oxidative stress as assessed in vivo by examining reductions in neuronal signaling and behavioral deficits and in vitro via H2O2‐induced decrements in striatal synaptosomal calcium buffering. Examinations have also revealed that BB supplementations are effective in antagonizing other age‐related changes in brain and behavior, as well as decreasing indices of inflammation and oxidative stress in gastrocnemius and quadriceps muscles. In ongoing studies we are attempting to determine the most effective BB polyphenolic components. To date, the anthocyanins show the most efficacy in penetrating the cell membrane and in providing antioxidant protection. In sum, our results indicate that increasing dietary intake of fruits and vegetables high in antioxidant activity may be an important component of a healthy living strategy designed to maximize neuronal and cognitive functioning into old age.
Ascorbic Acid, Blood Pressure, and the American Diet
Authors: BLOCK GLADYS
Published: July 2010

A large controlled study supported by the NIH, the DASH study (Dietary Approaches to Stop Hypertension), demonstrated that a diet rich in fruits and vegetables can reduce blood pressure in persons with moderate elevation in blood pressure (BP). Fruits and vegetables are important sources of antioxidants such as vitamin C and carotenoids. We conducted a study in which we fed people a diet deficient in vitamin C for 30 days, followed for another 30 days by a diet adequate in vitamin C. Their blood levels of vitamin C and blood pressure (BP) were tracked. Plasma vitamin C was inversely related to diastolic blood pressure one month later (correlation =−0.48,P< 0.0001). Persons whose blood levels of vitamin C went down the furthest on depletion had the highest blood pressure one month later. Persons in the lowest one‐fourth of the plasma vitamin C distribution had diastolic BP 7 mm Hg higher than did those in the upper one‐fourth of the plasma ascorbic acid distribution. Multivariate control for age, body mass index, other plasma antioxidants, and dietary energy, calcium, fiber, sodium, and potassium did not reduce the plasma vitamin C effect. We believe that this indicates that the tissue stores of vitamin C may be important in regulating blood pressure. It is often thought that Americans' intake of vitamin C is ample, since the average intake is about 100 mg/day. However, this average level obscures the fact that substantial numbers of people actually have habitually low intake levels and low blood levels. African Americans tend to have low blood levels of vitamin C as well as the highest risk of hypertension. Low intake of antioxidant‐rich fruits and vegetables may be one of the causes of hypertension.
Programmed Death Phenomena: From Organelle to Organism
Authors: SKULACHEV VLADIMIR P.
Published: July 2010

Programmed death phenomena appear to be inherent not only in living cells (apoptosis), but also in subcellular organelles (e.g., self‐elimination of mitochondria, called mitoptosis), organs (organoptosis), and even whole organisms (phenoptosis). In all these cases, the “Samurai law of biology”—it is better to die than to be wrong—seems to be operative. The operation of this law helps complicated living systems avoid the risk of ruin when a system of lower hierarchic position makes a significant mistake. Thus, mitoptosis purifies a cell from damaged and hence unwanted mitochondria; apoptosis purifies a tissue from unwanted cells; and phenoptosis purifies a community from unwanted individuals. Defense against reactive oxygen species (ROS) is probably one of the primary evolutionary functions of programmed death mechanisms. So far, it seems that ROS play a key role in the mito‐, apo‐, organo‐, and phenoptoses, which is consistent with Harman's theory of aging. Here a concept is described that tries to unite Weismann's hypothesis of aging as an adaptive programmed death mechanism and the generally accepted alternative point of view that considers aging as an inevitable result of accumulation in an organism of occasional injuries. It is suggested that injury accumulation is monitored by a system(s) actuating a phenoptotic death program when the number of injuries reaches some critical level. The system(s) in question are organized in such a way that the lethal case appears to be a result of phenoptosis long before the occasional injuries make impossible the functioning of the organism. It is stressed that for humans these cruel regulations look like an atavism that, if overcome, might dramatically prolong the human life span.
Metabolic Alterations and Shifts in Energy Allocations Are Corequisites for the Expression of Extended Longevity Genes in Drosophila
Authors: ARKING ROBERT , BUCK STEVEN , HWANGBO DAE‐SUNG , LANE MARK
Published: July 2010

Evolutionary theories suggest that the expression of extended longevity depends on the organism's ability to shift energy from reproduction to somatic maintenance. New data led us to reexamine our older data and integrate the two into a larger picture of the genetic and metabolic alterations required if the animal is to live long. Our Ra normal‐lived control strain can express any one of three different extended longevity phenotypes, only one of which involves significant and proportional increases in both mean and maximum longevity and thus a delayed onset of senescence. This phenotype is dependent on the up‐regulation of the antioxidant defense system (ADS) genes and enzymes. Animals that express this phenotype typically have a pattern of altered specific activities in metabolically important enzymes, suggesting they are necessary to support the NAD+/NADP+ reducing system required for the continued high ADS enzyme activities. Fecundity data suggests that the energy required for this higher level of somatic maintenance initially came from a reduced egg production. This was only transient, however, for the females significantly increased their fecundity in later generations while still maintaining their longevity. The energy required for this enhanced fecundity was probably obtained from an increased metabolic efficiency, for the mitochondria of the La long‐lived strain are metabolically more efficient and have a lower leakage of reactive oxygen species (ROS) to the cytosol. Selection pressures that do not lead to these shifts in energy allocations result in extended longevity phenotypes characterized by increased early survival or increased late survival but not by a delayed onset of senescence.
Pharmacological Interventions in Aging and Age‐associated Disorders
Authors: KITANI KENICHI , MINAMI CHIYOKO , YAMAMOTO TAKAKO , KANAI SETSUKO , IVY GWEN O. , CARRILLO MARIA‐CRISTINA
Published: July 2010

Past studies including our own have confirmed that chronic administration of deprenyl can prolong life spans of at least four different animal species. Pretreatment with the drug for several weeks increases activities of superoxide dismutase (SOD) and catalase (CAT) in selective brain regions. An up‐regulation of antioxidant enzyme activities can also be induced in organs such as the heart, kidney, spleen, and adrenal gland, and all are accompanied by an increase in mRNA levels for SODs in these organs. The effect of deprenyl on enzyme activities has a dose‐effect relationship of a typical inverted U shape. A similar inverted U shape also has emerged for the drug's effect on survival of animals. An apparent parallelism observed between these two effects of the drug seems to support our contention that the up‐regulation of antioxidant enzymes is at least partially responsible for the life‐prolonging effect on animals. Further, when a clinically applied dose of the drug for patients with Parkinson's disease was given to monkeys, SOD and CAT activities were increased in striatum of these monkeys, which suggests potential for the drug's applicability to humans. The drug was also found to increase concentrations of cytokines such as interleukin‐1β (IL‐1β) and tumor necrosis factor‐α (TNF‐α) in the above rat organs. Together with past reports demonstrating that deprenyl increases natural killer (NK) cell functions and interferon‐γ, and prevents the occurrence of malignant tumors in rodents and dogs, the mobilization of these humoral factors may therefore be included as possible mechanisms of action of deprenyl for its diverse antiaging and life‐prolonging effects. The potentials of propargylamines, (−)deprenyl in particular, for human use as antiaging drugs remain worthy of exploration in the future.
Oxidative Stress and Programmed Cell Death in Diabetic Neuropathy
Authors: VINCENT ANDREA M. , BROWNLEE MICHAEL , RUSSELL JAMES W.
Published: July 2010

Recent evidence in both animal models and human sural nerve biopsies indicates an association with oxidative stress, mitochondrial (Mt) membrane depolarization (MMD), and induction of programmed cell death (PCD). In streptozotocin (STZ)‐treated diabetic rats, hyperglycemia induces typical apoptotic changes as well as swelling and disruption of the Mt cristae in diabetic dorsal root ganglion neurons (DRG) and Schwann cells (SC), but these changes are only rarely observed in control neurons. In human sural nerve biopsies, from patients with diabetic sensory neuropathy, there is transmission electromicrograph evidence of swelling and disruption of the Mt and cristae compared to patients without peripheral neuropathy. In human SH‐SY5Y neurons, rat sensory neurons, and SC, in vivo, there is an increase in reactive oxygen species (ROS) after exposure to 20 mM added glucose. In parallel, there is an initial Mt membrane hyperpolarization followed by depolarization (MMD). In turn, MMD is coupled with cleavage of caspases. Various strategies aimed at inhibiting the oxidative burst, or stabilizing the ΔΨM, block induction of PCD. First, growth factors such as NGF can block induction of ROS and/or stabilize the ΔΨM. This, in turn, is associated with inhibition of PCD. Second, reduction of ROS generation in neuronal Mt prevents neuronal PCD. Third, up‐regulation of uncoupling proteins (UCPs), which stabilize the ΔΨM, blocks induction of caspase cleavage. Collectively, these findings indicate that hyperglycemic conditions observed in diabetes mellitus are associated with oxidative stress‐induced neuronal and SC death, and targeted therapies aimed at regulating ROS may prove effective in therapy of diabetic neuropathy.