bluuebunny/crossref_metadata_2025 huggingface dataset:
The Study on Hospital Information Systems Based on Post-Relational Database
Authors: Ji Zhi Gang , Chen Yan Zhen
Published: August 2010

In this paper, we take Oracle as the example of relational database, and Caché as a post-relational database. We implement the performance test between relational database and post-relational database in HIS. The results prove post-relational are much more efficient than relational database.
Simulation of Hybrid Electrical Vehicle Automated Mechanical Transmission Control System
Authors: Zhang Jin Dong , Qin Gui He , Huang Yong Ping , Zhang Xiao Long
Published: August 2010

For developing motor driven automated mechanical transmission of hybrid electrical vehicle, adjust and control the gear selecting motor, the gear shifting motor and the clutch motor. In the research of position-PID controller and robust disturbance observer, an automated mechanical transmission system based on position-PID was given. With Matlab, the position-PID controlling arithmetic and the controlling system models of the motors were built. Experimental results show that, a highly efficient and reliable automated mechanical transmission motor control system was developed.
Study on Microstructure of Semi-Solid Magnesium Alloy Manufactured by Gas Bubbles Stirring
Authors: Li Jiqiang , Zhang Lei , Dong Xuan Pu , Liu Wen , Zhang Zhao
Published: August 2010

The semi-solid slurry of AZ31 magnesium alloy was manufactured by gas bubbles stirring. The effects of stirring temperature and stirring time on the microstructure of semi-solid slurry were researched. The results indicate that it is feasible to manufacture the slurry with particle-like primary phases. When the stirring temperature is higher, the morphology of the primary a-Mg presents rosette-like morphology and the size of grain is coarse, and the morphology mainly was α- Mg dendrite at lower stirring temperature. Long stirring time could reduce dendrites and liquid phase, and made the non-dendritic grains well spheroidized. But the effects of longer stirring on shape and size of primary particles are not significant. The optimal process parameters for ideal semi-solid slurry manufactured were stired 3min at 645°C.
Synthesis and Photocatalytic Property of BiVO4/FeVO4 Composite Novel Photocatalyst
Authors: Wang Min , Liu Qiong , Zhang Dong
Published: August 2010

BiVO4/FeVO4 composite photocatalyst samples were prepared by calcining the mixture of FeVO4 and BiVO4 precusor which were prepared through liquid phase precipitation method for further increasing the photocatalytic efficiency of FeVO4. The catalysts were characterized by X-ray diffraction (XRD), scanning electron microsoope（SEM）and specific surface area (BET). The photocatalytic activity was evaluated by photocatalytic degradation of methyl orange (MO) solution under visible light. The XRD patterns indicate that BiVO4/FeVO4 composite photocatalysts consist of triclinic phase and the lattice was not distorted beacause of doping Bi. But the morphology change greatly and the specific surface area has little change. In the experimental conditions used, the optimal photocatalytic activity for all the prepared samples was reached when BiVO4 doping was 22 at%. The degradation rate of MO was increased by 20％ or so than that of pure FeVO4.
Study on the Orientation of Unidirectional C/C Composites
Authors: Wan Ju , Liu Xiu Jun , Li Tong Qi , Hu Zi Jun , Qiao Zhi Jun
Published: August 2010

This present investigation describes the orientation and its influence factors of unidirectional C/C composites prepared by PAN-based carbon fiber and mesophase pitch (AR-MP) through hot pressure molding process. And the orientation of C/C composites was analyzed by POM and XRD. The experimental results indicated that the AR-MP dispersed in carbon fiber had a strong flow texture, showed a matrix preferentially oriented parallel to fiber surface. Under the pressure of 25MPa, the orientation of composites was better than under 50MPa. Moreover, the sample orientation varies in the two directions both perpendicular to the direction of carbon fiber. Better orientation was obtained in the testing direction which was perpendicular to the direction of carbon fiber and molding pressure.
Analysis on Shear Mechanical Properties of Birch Laminated Veneer Lumber
Authors: Xue Bing , Hu Ying Cheng
Published: August 2010

There are many factors that affect the mechanical properties of laminated veneer lumber (LVL), such as the thickness of veneer, the compression ratio, the wood species and the density of LVL. In this paper, two different nondestructive testing (NDT) methods and the static shearing test were conducted on the birch (Betula platyphylla Suk.) LVL. The NDT methods included the flexural vibration method and surface wave propagation method. The effects of the compression ratio of LVL on the dynamic shear modulus and shear strength of LVL were investigated. The results showed that the dynamic shear modulus and shear strength of LVL were increased with the compression ratio of LVL increased, the increase tendency of NDT results and static shearing test results were consistent.
Study on Synthesis and Properties of a Novel Borate Ester Surfactant
Authors: Li Xiao Ning , Zheng Guo , Yang Hong Xiang
Published: August 2010

A new type of surfactant was prepared. The structure of the novel borate ester formed by reacting boric acid and lauryl alcohol and with diethanol amine was established by 11B, 1H NMR spectroscopy and IR spectrum. Testing it antistatic property, we found 0.3wt% dodecanol diethanol amine borate ester surfactant (the final product LNB) can make specific resistance of the polyester staple fiber be decreased from 1012 to 108 at the condition of 60% RH and 18°C. Because Amine compounds with nonbonding electrons can form the extra molecular coordination bond of nitrogen to boron and prevent hydrolysis of borate esters, it exhibits higher hydrolytic stability. And the novel borate ester surfactant shows a higher antibacterial activity. This paper mainly studies its application in modern spin finishes for polyester staple fiber.
Microstructure Characteristics of Eutectoid Pearlitic Steel after Equal Channel Angular Pressing at Room Temperature
Authors: Zhao Jun , Zhai Hong Yan , Zhang Han , Wu Xiang Nan , Pang Guo Xing , Wang Zhen Hua
Published: August 2010

An ultrafine microduplex structure was successfully produced through equal channel angular pressing (ECAP) at ambient temperature. According to the morphological characteristics of cementite lamellas, the deformed pearlite consists of shear break lamella, locally thinned lamella and irregularly bent lamella. The proportion of locally thinned lamella and irregularly bent lamella has increased with the pass number of ECAP. In addition, the deformed pearlitic ferrite became a supersaturated solid solution of carbon due to the partial dissolution of cementite during ECAP.
Experimental Studies for Burrs in Dry Drilling of Stacked Metal Materials
Authors: Liang Jie , Bi Shu Sheng
Published: August 2010

During the drilling of stacked materials, burrs forming on both the surface layer and the interlayer have some undesirable characters with regard to assembly quality, and deburring is a time-consuming and costly operation. This paper presented an experimental study on dry drilling of Ti-6Al-4V titanium alloy and 7075-T6 aluminium alloy stacked materials, which was performed by using uncoated cemented carbide drills. The burr size was evaluated at various spindle speeds, feed rates, stacking sequence and clamp force. Finally, the burr morphology was observed and analyzed. The best process parameters recorded in this paper were at the spindle speed of 2000r/min, the feed rate of 0.075mm/r, the pressure of 0.3MPa and the stacking sequence of the Ti-6Al-4V titanium alloy on top of the 7075-T6 aluminium alloy.
The Numerical Simulation Research of Steam Heating Process of Heated Mandrel Winding
Authors: Xu Jia Zhong , Qiao Ming , Zhang Wen Bo , Wang Xin Ying
Published: August 2010

The external curing method is usually adopted as the traditional molding process of thermoset fiber composite shell, which places the wound shell into the thermal compression reactor or the oven to cure. This kind of process greatly limits the molding efficiency because winding and curing proceed respectively and separately. The internal curing can be adopted because of the hollow structure of the cylinder-shaped shell, which heats the mandrel with high pressure steam to realize the in-situ curing of the wound shell. This paper researches the new fiber composite molding process named heated mandrel winding. Not only does the heated mandrel winding inherit the advantages of internal curing process, it also greatly improves molding efficiency and quality. This paper introduces the process principle of heated mandrel winding and uses the finite element analysis software FLUENT to carry out the numerical simulation of steam flow and heat transfer during the mandrel heating process, and the simulation results are verified by experiment. According to the simulation results, the distribution and changing course of the flow field and temperature field of the system are obtained, and the relationships between the physical quantities including pressure, temperature and velocity and the parameters of the steam control and channel structure are analyzed.
Determination of Nanocrystalline Fe80Cr20 Powder Based Alloys Using Williamson-Hall Method
Authors: Saryanto Hendi , Deni S. Khaerudini , Untoro Pudji , Saleh Mat Husin , Sebayang Darwin
Published: August 2010

The aim of this study is to determine the nanocrystalline size by using Williamson-Hall method of Fe80Cr20 powder which prepared by mechanical alloying process. X-rays diffraction line profile analysis was adopted to analyze the crystallite size and microstrains of Fe80Cr20 alloys powder. Transmission Electron Microscopy (TEM) was used to examine the microstructure morphology of the nanosized of Fe80Cr20 alloys. The crystallite size, microstrain, and lattice parameters were estimated by Williamson–Hall plot. The results showed that the mechanical alloying processes resulted the final product in nanocrystalline size range (below 12 nm) which confirmed by TEM observation and XRD line profile analysis.
Characteristic Varieties for a Class of Line Arrangements
Authors: Dinh Thi Anh Thu
Published: August 2010

Let be a line arrangement in the complex projective plane ℙ2, having the points of multiplicity ≥ 3 situated on two lines in , say H0 and H∞. Then we show that the non-local irreducible components of the first resonance variety are 2-dimensional and correspond to parallelograms ℙ in ℂ2 = ℙ2 \ H∞ whose sides are in and for which H0 is a diagonal.
Combined Administration of Taurine and Monoisoamyl Dmsa Protects Arsenic Induced Oxidative Injury in Rats
Authors: Flora Swaran J. S. , Chouhan Swapnila , Kannan Gurusamy M. , Mittal Megha , Swarnkar Harimohan
Published: August 2010

Arsenic is a naturally occurring element that is ubiquitously present in the environment. High concentration of naturally occurring arsenic in drinking water is a major health problem in different parts of the world. Despite arsenic being a health hazard and a well documented carcinogen, no safe, effective and specific preventive or therapeutic measures are available. Among various recent strategies adopted, administration of an antioxidant has been reported to be the most effective. The present study was designed to evaluate the therapeutic efficacy of monoisoamyl dimercaptosuccinic acid (MiADMSA), administered either individually or in combination with taurine post chronic arsenic exposure in rats. Arsenic exposed male rats (25 ppm, sodium arsenite in drinking water for 24 weeks) were treated with taurine (100 mg/kg, i.p., once daily), monoisoamyl dimercaptosuccinic acid (MiADMSA) (50 mg/kg, oral, once daily) either individually or in combination for 5 consecutive days. Biochemical variables indicative of oxidative stress along‐with arsenic concentration in blood, liver and kidney were measured. Arsenic exposure significantly reduced blood δ‐aminolevulinic acid dehydratase (ALAD) activity, a key enzyme involved in the heme biosynthesis and enhanced zinc protoporphyrin (ZPP) level. Clinical hematological variables like white blood cells (WBC), mean cell hemoglobin (MCH), and mean cell hemoglobin concentration (MCHC) showed significant decrease with a significant elevation in platelet (PLT) count. These changes were accompanied by significant decrease in superoxide dismutase (SOD) activity and increased catalase activity. Arsenic exposure caused a significant decrease in hepatic and renal glutathione (GSH) level and an increase in oxidized glutathione (GSSG). These biochemical changes were correlated with an increased uptake of arsenic in blood, liver and kidney. Administration of taurine significantly reduced hepatic oxidative stress however co‐administration of a higher dose of taurine (100 mg/kg) and MiADMSA provided more pronounced effects in improving the antioxidant status of liver and kidney and reducing body arsenic burden compared to the individual treatment of MiADMSA or taurine. The results suggest that in order to achieve better effects of chelation therapy, co‐administration of taurine with MiADMSA might be preferred.
Hypoxia Mediated Release of Endothelial Microparticles and Increased Association of S100A12 with Circulating Neutrophils
Authors: Vince Rebecca V. , Chrismas Bryna , Midgley Adrian W. , McNaughton Lars R. , Madden Leigh A.
Published: August 2010

Microparticles are released from the endothelium under normal homeostatic conditions and have been shown elevated in disease states, most notably those characterised by endothelial dysfunction. The endothelium is sensitive to oxidative stress/status and vascular cell adhesion molecule‐1 (VCAM‐1) expression is upregulated upon activated endothelium, furthermore the presence of VCAM‐1 on microparticles is known. S100A12, a calcium binding protein part of the S100 family, is shown to be present on circulating leukocytes and is thought a sensitive marker to local inflammatory process, which may be driven by oxidative stress. Eight healthy males were subjected to breathing hypoxic air (15% O2, approximately equivalent to 3000 metres altitude) for 80 minutes in a temperature controlled laboratory and venous blood samples were processed immediately for VCAM‐1 microparticles (VCAM‐1 MP) and S100A12 association with leukocytes by flow cytometry. A pre‐hypoxic blood sample was used for comparison. Both VCAM‐1 MP and S100A12 association with neutrophils were significantly elevated post hypoxic breathing later declining to levels observed in the pre‐test samples. A similar trend was observed in both cases and a correlation may exist between these two markers in response to hypoxia. These data offer evidence using novel markers of endothelial and circulating blood responses to hypoxia.
Oxidative Stress and Antioxidant Defense Mechanisms Linked to Exercise During Cardiopulmonary and Metabolic Disorders
Authors: Fisher-Wellman Kelsey , Bell Heather K. , Bloomer Richard J.
Published: August 2010

Oxidative stress has been implicated in the pathophysiology of multiple human diseases, in addition to the aging process. Although various stimuli exist, acute exercise is known to induce a transient increase in reactive oxygen and nitrogen species (RONS), evident by several reports of increased oxidative damage following acute bouts of aerobic and anaerobic exercise. Although the results are somewhat mixed and appear disease dependent, individuals with chronic disease experience an exacerbation in oxidative stress following acute exercise when compared to healthy individuals. However, this increased oxidant stress may serve as a necessary “signal” for the upregulation in antioxidant defenses, thereby providing protection against subsequent exposure to prooxidant environments within susceptible individuals. Here we present studies related to both acute exercise‐induced oxidative stress in those with disease, in addition to studies focused on adaptations resulting from increased RONS exposure associated with chronic exercise training in persons with disease.
Oxidative Stress and Anxiety: Relationship and Cellular Pathways
Authors: Bouayed Jaouad , Rammal Hassan , Soulimani Rachid
Published: August 2010

High O2 consumption, modest antioxidant defenses and a lipid‐rich constitution make the brain highly vulnerable to redox imbalances. Oxidative damage in the brain causes nervous system impairment. Recently, oxidative stress has also been implicated in depression, anxiety disorders and high anxiety levels. The findings which establish a link between oxidative stress and pathological anxiety have inspired a number of other recent studies focusing on the link between oxidative status and normal anxiety and also on a possible causal relationship between cellular oxidative stress and emotional stress. This review examines the recent discoveries made on the link between oxidative status and normal anxiety levels and the putative role of oxidative stress in genesis of anxiety. We discuss the different opinions and questions that exist in the field and review the methodological approaches that are being used to determine a causal relationship between oxidative and emotional stress.
Lipid Peroxidation and Antioxidant Status in Head and Neck Squamous Cell Carcinoma Patients
Authors: Gupta Aashita , Bhatt Madan L. B. , Misra Mithilesh K.
Published: August 2010

Oxidative stress, a consequence of an imbalance between the formation and inactivation of reactive oxygen species, may be involved in the pathogenesis of many diseases including cancer. To evaluate the magnitude of oxidative stress, a study on the plasma levels of superoxide dismutase, total thiols, ascorbic acid and malondialdehyde (MDA) has been done in head and neck squamous cell carcinoma patients before the start of any oncological treatment and compared with healthy controls. The specific activity of superoxide dismutase in cancer patients is decreased significantly when compared to the control (p < 0.05). The total thiol and ascorbic acid levels are significantly reduced (p < 0.005) whereas MDA levels are significantly increased in the patients (p < 0.00005). Our findings show that the oxidative stress is elevated in cancer patients as evidenced by elevated levels of lipid peroxidation products and depletion of enzymatic and non‐enzymatic antioxidants.
Pro‐Inflammatory and Oxidative Stress Pathways which Compromise Sperm Motility and Survival May Be Altered by L‐Carnitine
Authors: Abd-Allah Adel R. A. , Helal Gouda K. , Al-Yahya Abdulaziz A. , Aleisa Abdulaziz M. , Al-Rejaie Salim S. , Al-Bakheet Saleh A.
Published: August 2010

The testis is an immunologically privileged organ. Sertoli cells can form a blood‐testis barrier and protect sperm cells from self‐immune system attacks. Spermatogenesis may be inhibited by severe illness, bacterial infections and chronic inflammatory diseases but the mechanism(s) is poorly understood. Our objective is to help in understanding such mechanism(s) to develop protective agents against temporary or permanent testicular dysfunction. Lipopolysaccaride (LPS) is used as a model of animal sepsis while L‐carnitine (LCR) is used as a protective agent. A total of 60 male Swiss albino rats were divided into four groups (15/group). The control group received Saline; the 2nd group was given LCR (500 mg/kg i.p, once). The third group was treated with LPS (5 mg/kg i.p once) and the fourth group received LCR then LPS after three hours. From each group, five rats were used for histopathological examination. Biochemical parameters were assessed in the remaining ten rats. At the end of the experiment, animals were lightly anaesthetized with ether where blood samples were collected and testes were dissected on ice. Sperm count and motility were evaluated from cauda epididymis in each animal. Also, oxidative stress was evaluated by measuring testicular contents of reduced glutathione (GSH), malondialdehyde (MDA) and 8‐hydroxydeoxyguanosine (8‐HDG, the DNA adduct for oxidative damage) in testicular DNA. The pro‐inflammatory mediator nitric oxide (NO) in addition to lactate dehydrogenase (LDHx) isoenzyme‐x activity as an indicator for normal spermatozoal metabolism were assessed in testicular homogenate. Serum interlukin (IL)‐2 level was also assessed as a marker for T‐helper cell function. The obtained data revealed that LPS induced marked reductions in sperm′s count and motility, obstruction in seminiferous tubules, hypospermia and dilated congested blood vessels in testicular sections concomitant with decreased testicular GSH content and LDHx activity. Moreover, the testicular levels of MDA, 8‐HDG (in testicular DNA) and NO as well as serum IL‐2 level were increased. Administration of LCR before LPS returned both sperm count and motility to normal levels. Also, contents of testicular GSH, MDA, 8‐HDG and NO returned back to the corresponding control values. In addition, serum IL‐2 level as well as histological abnormalities were markedly improved in LCR + LPS‐treated rats. In conclusion, LPS increased proinflammatory and oxidative stress markers in the testis leading to a marked testicular dysfunction. L‐carnitine administration ameliorates these effects by antioxidant and/or anti‐inflammatory mechanisms suggesting a protective role against male infertility in severely infected or septic patients.
Specific Factors Influence the Success of Autologous and Allogeneic Hematopoietic Stem Cell Transplantation
Authors: Gonçalves Thissiane L. , Benvegnú Dalila M. , Bonfanti Gabriela
Published: August 2010

Successful hematopoietic stem cell transplantation (HSCT), both autologous and allogeneic, requires a rapid and durable engraftment, with neutrophil (>500/µL) and platelet (>20,000/µL) reconstitution. Factors influencing engraftment after autologous or allogeneic HSCT were investigated in 65 patients: 25 autologous peripheral stem cell transplantation (PBSCT) and 40 allogeneic bone marrow transplantation (BMT) patients. The major factor affecting engraftment was the graft source for HSCT. Neutrophil and platelet recovery were more rapid in autologous PBSCT than in allogeneic BMT [neutrophil occurring in median on day 10.00 (09.00/11.00) and 19.00 (16.00/23.00) and platelet on day 11.00 (10.00/13.00) and 21.00 (18.00/25.00), respectively; p < 0.0001]. The type of disease also affected engraftment, where multiple myeloma (MM) and lymphoma showed faster engraftment when compared with leukemia, syndrome myelodysplastic (SMD) and aplastic anemia (AA) and MM presented the best overall survival (OS) in a period of 12 months. Other factors included the drug used in the conditioning regimen (CR), where CBV, melphalan (M‐200) and FluCy showed faster engraftment and M‐200 presented the best OS, in a period of 12 months and age, where 50–59 years demonstrated faster engraftment. Sex did not influence neutrophil and platelet recovery.
Urate Oxidase Knockdown Decreases Oxidative Stress in a Murine Hepatic Cell Line
Authors: Cleveland Beth M. , Leonard Stephen S. , Klandorf Hillar , Blemings Kenneth P.
Published: August 2010

Humans, birds, and some primates do not express the uric acid degrading enzyme urate oxidase (UOX) and, as a result, have plasma uric acid concentrations higher than UOX expressing animals. Although high uric acid concentrations are suggested to increase the antioxidant defense system and provide a health advantage to animals without UOX, knockout mice lacking UOX develop pathological complications including gout and kidney failure. As an alternative to the knockout model, RNA interference was used to decrease UOX expression using stable transfection in a mouse hepatic cell line (ATCC, FL83B). Urate oxidase mRNA was reduced 66% (p < 0.05) compared to wild type, as measured by real time RT‐PCR. To determine if UOX knockdown resulted in enhanced protection against oxidative stress, cells were challenged with hexavalent chromium (Cr(VI)) or 3‐morpholinosydnonimine hydrochloride (SIN‐1). Compared to wild type, cells with UOX knockdown exhibited a 37.2 ± 3.5% reduction (p < 0.05) in the electron spin resonance (ESR) signal after being exposed to Cr(VI) and displayed less DNA fragmentation (p < 0.05) following SIN‐1 treatment. Cell viability decreased in wild type cells (p < 0.05), but not cells with UOX knockdown, after treatment with SIN‐1. These results are consistent with an increased intracellular uric acid concentration and an increased defense against oxidative stress.
Implications for Degenerative Disorders: Antioxidative Activity, Total Phenols, Flavonoids, Ascorbic Acid, β‐Carotene and β‐Tocopherol in Aloe vera
Authors: Ozsoy Nurten , Candoken Eda , Akev Nuriye
Published: August 2010

In order to demonstrate whether the known biological effects of Aloe vera (L.) Burm. fil. could correlate with the antioxidant activity of the plant, the antioxidant activity of the aqueous leaf extract was investigated. The present study demonstrated that the aqueous extract from A. vera leaves contained naturally occuring antioxidant components, including total phenols, flavonoids, ascorbic acid, β‐carotene and α‐tocopherol. The extract exhibited inhibitory capacity against Fe3+/ascorbic acid induced phosphatidylcholine liposome oxidation, scavenged stable DPPH•, ABTS•+ and superoxide anion radicals, and acted as reductant. In contrast, the leaf inner gel did not show any antioxidant activity. It was concluded that the known beneficial effects of Aloe vera could be attributed to its antioxidant activity and could be related to the presence of phenolic compounds and antioxidant vitamins.
Methanol Extract of Ocimum Gratissimum Protects Murine Peritoneal Macrophages from Nicotine Toxicity By Decreasing Free Radical Generation, Lipid and Protein Damage and Enhances Antioxidant Protection
Authors: Mahapatra Santanu Kar , Chakraborty Subhankari Prasad , Das Subhasis , Roy Somenath
Published: August 2010

In the present study, methanol extract of Ocimum gratissimum Linn (ME‐Og) was tested against nicotine‐induced murine peritoneal macrophage in vitro. Phytochemical analysis of ME‐Og shown high amount of flavonoid and phenolic compound present in it. The cytotoxic effect of ME‐Og was studied in murine peritoneal macrophages at different concentrations (0.1 to 100 µg/ml) using the 3‐(4, 5‐dimethylthiazol‐2‐yl)‐2, 5 diphenyltetrazolium bromide (MTT) method. To establish the protective role of ME‐Og against nicotine toxicity, peritoneal macrophages from mice were treated with nicotine (10 mM), nicotine + ME‐Og (1 to 25 µg/ml) for 12 h in culture media. The significantly (p < 0.05) increased super oxide anion generation, reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity, myeloperoxidase (MPO) activity, lipid peroxidation, protein carbonyls, oxidized glutathione levels were observed in nicotine‐treated group as compared to control group; those were significantly (p < 0.05) reduced in ME‐Og supplemented groups in concentration dependent manner. More over, significantly (p < 0.05) reduced antioxidant status due to nicotine exposure was effectively ameliorated by ME‐Og supplementation in murine peritoneal macrophages. Among the different concentration of ME‐Og, maximum protective effect was observed by 25 µg/ml, which does not produce significant cell cytotoxicity in murine peritoneal macrophages. These findings suggest the potential use and beneficial role of O. gratissimum as a modulator of nicotine‐induced free radical generation, lipid‐protein damage and antioxidant status in important immune cell, peritoneal macrophages.
Novel, Unifying Mechanism for Mescaline in The Central Nervous System: Electrochemistry, Catechol Redox Metabolite, Receptor, Cell Signaling and Structure Activity Relationships
Authors: Kovacic Peter , Somanathan Ratnasamy
Published: August 2010

A unifying mechanism for abused drugs has been proposed previously from the standpoint of electron transfer. Mescaline can be accommodated within the theoretical framework based on redox cycling by the catechol metabolite with its quinone counterpart. Electron transfer may play a role in electrical effects involving the nervous system in the brain. This approach is in accord with structure activity relationships involving mescaline, abused drugs, catecholamines and etoposide. Inefficient demethylation is in keeping with the various drug properties, such as requirement for high dosage and slow acting.

There is a discussion of receptor binding, electrical effects, cell signaling and other modes of action. Mescaline is a nonselective, seretonin receptor agonist. 5‐HTP receptors are involved in the stimulus properties. Research addresses the aspect of stereochemical requirements. Receptor binding may involve the proposed quinone metabolite and/or the amino sidechain via protonation. Electroencephalographic studies were performed on the effects of mescaline on men. Spikes are elicited by stimulation of a cortical area. The potentials likely originate in nonsynaptic dendritic membranes. Receptor‐mediated signaling pathways were examined which affect mescaline behavior. The hallucinogen belongs to the class of 2AR agonists which regulate pathways in cortical neurons. The research identifies neural and signaling mechanisms responsible for the biological effects. Recently, another hallucinogen, psilocybin, has been included within the unifying mechanistic framework. This mushroom constituent is hydrolyzed to the phenol psilocin, also active, which is subsequently oxidized to an ET o‐quinone or iminoquinone.
Role of Tyrosine Phosphorylation in The Antioxidant Effects of The P75 Neurotrophin Receptor
Authors: Zhang Tong , Mi Zhiping , Schor Nina F.
Published: August 2010

The p75 neurotrophin receptor (p75NTR) is an α‐and γ‐secretase substrate expressed preferentially in the cholinergic neurons of the nucleus basalis of Meynert, the hippocampus, and the cerebellum of the adult brain. Mutations of the γ‐secretase, presenilin, have been implicated in familial Alzheimer′s disease. Furthermore, oxidative and inflammatory injury to the cholinergic neurons of the nucleus basalis of Meynert and hippocampus plays a critical role in the pathology of Alzheimer′s disease. The intracellular domain of p75NTR (p75ICD) is the α‐ and γ‐secretase cleavage fragment of the holoreceptor that functions as an antioxidant in PC12 rat pheochromocytoma cells. Phosphorylation of the receptor is thought to be necessary for many of its functions, and two tyrosines in p75ICD have been among the functionally important phosphorylation sites. Site‐directed mutagenesis was used to generate three p75ICD mutants that cannot be phosphorylated at either or both tyrosines, respectively. Each of these mutants was expressed in p75NTR‐deficient PC12 cells to determine the effects of blocking phosphorylation at specific sites on the antioxidant activity of p75ICD. Interfering with phosphorylation at tyrosine‐337 impairs antioxidant function, while interfering with phosphorylation at tyrosine‐366 does not, and may in fact impart protection from oxidant stress. Neither MAPK (i.e., p38, ERK1, ERK2) content nor NF‐κB activation accounts for the differential sensitivity to oxidant stress among the differentially phosphorylated p75NTR cell lines. However, differences in the time course of ERK1,2 phosphorylation among the lines account in large measure for their differential oxidant sensitivity. The phosphorylation state of specific sites on p75ICD may modulate the resistance of neurons in Alzheimer′s disease‐relevant brain regions to oxidant stress.
Plant Polyphenols as Dietary Antioxidants in Human Health and Disease
Authors: Pandey Kanti Bhooshan , Rizvi Syed Ibrahim
Published: August 2010

Polyphenols are secondary metabolites of plants and are generally involved in defense against ultraviolet radiation or aggression by pathogens. In the last decade, there has been much interest in the potential health benefits of dietary plant polyphenols as antioxidant. Epidemiological studies and associated meta‐analyses strongly suggest that long term consumption of diets rich in plant polyphenols offer protection against development of cancers, cardiovascular diseases, diabetes, osteoporosis and neurodegenerative diseases. Here we present knowledge about the biological effects of plant polyphenols in the context of relevance to human health.
The Fat-1 Transgene in Mice Increases Antioxidant Potential, Reduces Pro‐Inflammatory Cytokine Levels, and Enhances PPARγ and SIRT‐1 Expression on a Calorie Restricted Diet
Authors: Rahman Md Mizanur , Halade Ganesh V. , Bhattacharya Arunabh , Fernandes Gabriel
Published: August 2010

Both n‐3 fatty acids (FA) and calorie‐restriction (CR) are known to exert anti‐inflammatory and anti‐oxidative effects in animals and humans. In this study, we investigated the synergistic anti‐inflammatory and anti‐oxidative capacity of n‐3 FA and CR using Fat‐1 transgenic mice (Fat‐1) that are capable of converting n‐6 FA to n‐3 FA endogenously. Wild type (WT) and Fat‐1 mice were maintained on ad libitum (AL) or CR (40% less than AL) AIN‐93 diet supplemented with 10% corn oil (rich in n‐6 FA) for 5 months. Significantly lower levels of n‐6/n‐3 FA ratio were observed in serum, muscle and liver of Fat‐1 mice fed AL or CR as compared to that of WT mice fed AL or CR. Muscle catalase (CAT), super oxide dismutase (SOD), glutathione peroxidase (GPX) activities, and liver CAT and SOD activities were found higher in Fat‐1 mice as compared to that of WT mice. These activities were more pronounced in Fat‐1/CR group as compared to other groups. Serum pro‐inflammatory markers, such as tumor necrosis factor (TNF)α, interleukin (IL)‐1β and IL‐6 were found lower in Fat‐1 mice, as compared to that of WT mice. This anti‐inflammatory effect was also more pronounced in Fat‐1/CR group as compared to that of other groups. Furthermore, significantly higher levels of peroxisome proliferator‐activated receptor (PPA R)gamma and life prolonging gene, sirtuin (SIRT)‐1 expression were found in liver of Fat‐1/CR mice, as compared to that of WT/CR mice. These data suggest that n‐3 FA along with moderate CR may prolong lifespan by attenuating inflammation and oxidative stress.
cAMP Activates The generation of Reactive Oxygen Species and Inhibits The Secretion of IL‐6 in Peripheral Blood Mononuclear Cells from Type 2 Diabetic Patients
Authors: Isoni Camila Armond , Borges Érica Abreu , Veloso Clara Araújo , Mattos Rafael Teixeira , Chaves Miriam Martins , Nogueira-Machado José Augusto
Published: August 2010

Peripheral blood mononuclear cells (PBMNC) from patients with type 2 diabetes (DM2) have generated higher levels of reactive oxygen species (ROS) that were higher than those in cells from healthy individuals. In the presence of a cAMP‐elevating agent, ROS production was significantly activated in PBMNC from DM2 patients but it was inhibited in cells from healthy subjects. Higher levels of IL‐6 has been detected in the supernatant of PBMNC cultures from DM2 patients in comparison with healthy controls. When cells were cultured in the presence of a cAMP‐elevating agent, the level of IL‐6 decreased has by 46% in the supernatant of PBMNC from DM2 patients but it remained unaltered in controls. No correlations between ROS and IL‐6 levels in PBMNC from DM2 patients or controls have been observed. Secretions of IL‐4 or IFN by PBMNC from patients or controls have not been affected by the elevation of cAMP. cAMP elevating agents have activated the production of harmful reactive oxidant down modulated IL‐6 secretion by these cells from DM2 patients, suggesting an alteration in the metabolic response possibly due to hyperglicemia. The results suggest that cAMP may play an important role in the pathogenesis of diabetes.
Clinical Physiology and Mechanism of Dizocilpine (MK‐801): Electron Transfer, Radicals, Redox Metabolites and Bioactivity
Authors: Kovacic Peter , Somanathan Ratnasamy
Published: August 2010

Dizocilpine (MK‐801), an extensively investigated drug possessing secondary amine and benzenoid functions, displays a wide array of biological properties, including anticonvulsant and anesthetic. There is scant discussion of biomechanism. A relevant, important finding is formation of oxidative metabolites in the hydroxylamine and phenolic categories. Analogy to cocaine metabolites suggests participation of redox entities, such as, hydroxylamine, nitroxide and nitrosonium, which can lead to electron transfer and radical formation. There is also similarity to metabolism by 3,3′‐iminodipropionitrile and phencyclidine. Alternatively, the phenolic metabolites are well‐known precursors of ET quinones. The review documents various physiological effects, mainly involving the central nervous system. Also of interest are the pro‐ and anti‐oxidant properties. Considerable attention has been paid to MK‐801 as an antagonist of the N‐methyl‐D‐aspartate receptor in the glutamate category. This aspect is often associated with effects on the central nervous system. The review also provides recent literature dealing with MK‐801/NMDA receptor in various areas of bioactivity. Studies were made of MK‐801 involvement in working memory processing. Deficits in behavior were noted after administration of the drug. Treatment of mice with dizocilpine induced learning impairment. The influence of MK‐801 on fear has been investigated. The substance is known to exert an analgesic effect in pain control. A number of reports deal with anesthetic properties.
Role of Peroxiredoxin III in the Pathogenesis of Pre‐eclampsia as Evidenced in Mice
Authors: Li Lianqin , Obinata Masuo , Hori Katsuyoshi
Published: August 2010

As a member of peroxiredoxin (Prx) family, PrxIII has been demonstrated to play an important role in scavenging intracellular reactive oxygen species (ROS). Since PrxIII knockout mice exhibited oxidative stress in placentas resembling pathophysiologic changes in placentas of human pre‐eclampsia, we measured blood pressure through the carotid artery and detected oxidative status by western blotting in pregnant mice. We did not notice hypertension in pregnant PrxIII knockout mice as compared with wild‐type littermates, although endothelin‐1 was overexpressed in PrxIII‐deficient placentas. Our results indicate that PrxIII is not involved in pre‐eclamptic development. Instead, PrxIII is an indispensable antioxidant in placentas where oxidative stress exists.
Modulation of Ionizing Radiation Induced Oxidative Imbalance by Semi‐Fractionated Extract of Piper betle: An In Vitro and In Vivo Assessment
Authors: Verma Savita , Gupta Manju Lata , Dutta Ajaswrata , Sankhwar Sanghmitra , Shukla Sandeep Kumar , Flora Swaran J. S.
Published: August 2010

The study was planned to evaluate modulatory effect of aqueous extract of Piper betle leaf (PBL) on ionizing radiation mediated oxidative stress leading to normal tissues damage during radiotherapy and other radiation exposures. The total polyphenols and flavonoids known as free radical scavenger (chelators) were measured in the extract. To ascertain antioxidant potential of PBL extract, we studied free radical scavenging, metal chelation, reducing power, lipid peroxidation inhibition and ferric reducing antioxidant properties (FRAP ) using in vitro assays. Mice were exposed to varied radiation doses administered with the same extract prior to irradiation to confirm its oxidative stress minimizing efficacy by evaluating ferric reducing ability of plasma, reduced glutathione, lipid peroxidation and micro‐nuclei frequency. PBL extract was effective in scavenging DPPH (up to 92% at 100 µg/ml) and superoxide radicals (up to 95% at 80 µg/ml), chelated metal ions (up to 83% at 50 µg/ml) and inhibited lipid peroxidation (up to 45.65% at 500 µg/ml) in a dose dependant manner using in vitro model. Oral administration of PBL extract (225 mg/kg body weight) 1 hr before irradiation in mice significantly enhanced (p < 0.01) radiation abated antioxidant potential of plasma and GSH level in all the observed organs. The treatment with extract effectively lowered the radiation induced lipid peroxidation at 24 hrs in all the selected organs with maximum inhibition in thymus (p < 0.01). After 48 hrs, lipid peroxidation was maximally inhibited in the group treated with the extract. Frequency of radiation induced micronucleated cells declined significantly (34.78%, p < 0.01) at 24 hrs post‐irradiation interval by PBL extract administration. The results suggest that PBL extract has high antioxidant potential and relatively non‐toxic and thus could be assertively used to mitigate radiotherapy inflicted normal tissues damage and also injuries caused by moderate doses of radiation during unplanned exposures.
Calcific Uremic Arteriolopathy: Pathophysiology, Reactive Oxygen Species and Therapeutic Approaches
Authors: Sowers Kurt M. , Hayden Melvin R.
Published: August 2010

Calcific uremic arteriolopathy (CUA)/calciphylaxis is an important cause of morbidity and mortality in patients with chronic kidney disease requiring renal replacement. Once thought to be rare, it is being increasingly recognized and reported on a global scale. The uremic milieu predisposes to multiple metabolic toxicities including increased levels of reactive oxygen species and inflammation. Increased oxidative stress and inflammation promote this arteriolopathy by adversely affecting endothelial function resulting in a prothrombotic milieu and significant remodeling effects on vascular smooth muscle cells. These arteriolar pathological effects include intimal hyperplasia, inflammation, endovascular fibrosis and vascular smooth muscle cell apoptosis and differentiation into bone forming osteoblast‐like cells resulting in medial calcification. Systemic factors promoting this vascular condition include elevated calcium, parathyroid hormone and hyperphosphatemia with consequent increases in the calcium × phosphate product. The uremic milieu contributes to a marked increased in upstream reactive oxygen species—oxidative stress and subsequent downstream increased inflammation, in part, via activation of the nuclear transcription factor NFκB and associated downstream cytokine pathways. Consitutive anti‐calcification proteins such as Fetuin‐A and matrix GLA proteins and their signaling pathways may be decreased, which further contributes to medial vascular calcification. The resulting clinical entity is painful, debilitating and contributes to the excess morbidity and mortality associated with chronic kidney disease and end stage renal disease. These same histopathologic conditions also occur in patients without uremia and therefore, the term calcific obliterative arteriolopathy could be utilized in these conditions.
Sedimentation flux in a large subtropical lake: Spatiotemporal variations and relation to primary productivity
Authors: Ostrovsky Ilia , Yacobi Yosef Z.
Published: August 2010

Spatial and temporal heterogeneity in sedimentation of particulate organic material (POM) was studied in a large subtropical lake, and its export from the upper mixed layer was quantified. Sedimentation fluxes were measured over 4 yr with traps deployed in pelagic and littoral areas, the benthic boundary layer (BBL), and the lake interior. Analysis of fluxes and composition of collected material showed that traps deployed at the lake periphery and in the BBL notably overestimate the export flux of newly produced POM. The best estimation of the primary production (PP) export from the upper mixed layer was achieved when traps were deployed in the quiescent hypolimnion, where the effect of lake boundaries is negligible. The proportion and composition of POM exported from the upper productive stratum was dependent on lake thermal and chemical structure and on the dominant phytoplankton species. The dynamics of photopigments (chlorophyll and β‐carotene) collected in hypolimnetic traps reflected the composition and abundance of phytoplankton in the upper mixed stratum. Despite large variation in algal community composition, the ratio of POM sedimentation flux to PP (export ratio) changed only slightly (average ~ 20%) throughout the stratified period. The observed temporal and spatial variability of sedimentation flux in response to ambient conditions was influenced by secondary processes (resuspension at the lake boundaries and oversampling under turbulent conditions) as intensely as by the actual export of POM.
Global analysis of the relation between aerosols and short-lived trace gases
Authors: Veefkind J. P. , Boersma K. F. , Wang J. , Kurosu T. , Krotkov N. , Levelt P. F.
Published: August 2010

Abstract. The spatial and temporal correlations between concurrent satellite observations of aerosol optical thickness (AOT) from the Moderate Resolution Imaging Spectroradiometer (MODIS) and tropospheric columns of nitrogen dioxide, sulfur dioxide, and formaldehyde from the Ozone Monitoring Instrument (OMI) are used to infer information on the global composition of aerosol particles. When averaging the satellite data over large regions and longer time periods, we find significant correlation between MODIS AOT and OMI trace gas columns for various regions in the world. This suggests that enhanced aerosol and trace gas concentrations originate from common sources, such as fossil fuel combustion, biomass burning, and organic compounds released from the biosphere. This leads us to propose that satellite-inferred AOT to NO2 ratios for regions with comparable photochemical regimes can be used as indicators for the relative (local) efficiency of combustion processes. Indeed, satellites observe low AOT to NO2 ratios over the eastern United States and western Europe, and high AOT to NO2 ratios over comparably industrialized regions in eastern Europe and China. Emission databases and OMI SO2 observations over these regions suggest a much stronger sulfur contribution to aerosol formation than over the well-regulated areas of the eastern United States and western Europe. Furthermore, satellite observations show AOT to NO2 ratios are a factor 100 higher over biomass burning regions than over industrialized areas, reflecting the unregulated burning practices with strong primary particle emissions in the tropics compared to the heavily controlled combustion processes in the industrialized Northern Hemisphere. Simulations with a global chemistry transport model (GEOS-Chem) capture most of these differences, providing some confidence in our understanding of aerosol sources, formation mechanisms, and sinks. Wintertime aerosol concentrations show strongest correlations with NO2 throughout most of the Northern Hemisphere. During summertime, AOT is often (also) correlated with enhanced HCHO concentrations, reflecting the importance of secondary organic aerosol formation in that season. We also find significant correlations between AOT and HCHO over biomass burning regions, the tropics in general, and over industrialized regions in southeastern Asia. The distinct summertime maximum in AOT (0.4 at 550 nm) and HCHO over the southeastern United States strengthens existing hypotheses that local emissions of volatile organic compounds lead to the formation of secondary organic aerosols there. GEOS-Chem underestimates the AOT over the southeastern United States by a factor of 2, most likely due to too strong precipitation and too low SOA yield in the model.
Estimation of predictive hydrological uncertainty using quantile regression: examples from the national flood forecasting system (England and Wales)
Authors: Weerts A. H. , Winsemius H. C. , Verkade J. S.
Published: August 2010

Abstract. In this paper, a is presented for assessing the predictive uncertainty of rainfall-runoff and hydraulic forecasts that conditions forecasts uncertainty on the forecasted value itself, based on retrospective quantile regression of hindcasted water level forecasts and forecast errors. To test the robustness of the method, a number of retrospective forecasts for different catchments across England and Wales having different size and hydrological characteristics have been used to derive in a probabilistic sense the relation between simulated values of discharges and water levels, and matching errors. From this study, we can conclude that using quantile regression for estimating forecast errors conditional on the forecasted water levels provides an extremely simple, efficient and robust means for uncertainty estimation of deterministic forecasts.