Low Methyl Research Articles

Hyperphosphorylation of Tau Protein in Down ’s Dementia and Alzheimer’s Disease: Methylation and Implications in Prevention and Therapy

The changes of insulin signaling, calcium signaling, mitochondrial decline and oxidative stress have been implicated in the hyperphosphorylation of tau protein found in Downs syndrome dementia. Such pathogenic etiologies have clear implications in the prevention and therapy of Down’s syndrome (DS) dementia. The occurrence of methylation defects in DS is discussed and though controversial, more recent studies do show significance. Kinases such as DYK1A and GlcNA cylation are discussed as well as a Cdk5 inhibitory peptide (CIP). Even sleep medicine has been demonstrated in that seniors, who have better sleep, suffer less cognitive decline than those with sleep problems with enhanced clearance of β amyloid and tau neurofibrillary tangles. Studies have reported a high incidence of sleep problems in Down’s. Environmental toxin arsenite and low dose methyl mercury have been speculated to induce tau phosphorylation. Dietary changes to low glycemic carbohydrate and gluten avoidance should be made. Adding B vitamins may be equally important to prevent brain atrophy especially in those with MTHFR and MTRR gene defects. The therapeutic strategy of reducing insulin resistance by up regulation of PPARS alpha with glitazones and decreasing calcium influx into the mitochondria is mentioned. Protecting mitochondrial decline from oxidative stress with antioxidants, and treatment with CBD, polyphenols, ellagic acid, resveratrol and other grape bioflavinoids and moderate magnetic fields is discussed

The effects of pectins on life span and stress resistance in Drosophila melanogaster

The composition of diet is one of the major determining factors for lifespan. The dietary pectins are known to have anti-inflammatory properties and may influence aging and longevity. Here we demonstrate the lifespan-extending effect of the low methyl esterified (LM) commercial pectins CU701 and AU701 in wild-type strain of Drosophila melanogaster. The high methyl esterified (HM) pectin CU201 did not affect lifespan. LM pectin did not increase lifespan of males with a mutation in the Toll adaptor Myd88 gene and in both males and females with a mutation in the NF-κB ortholog Relish. LM pectin CU701 increased imagoes survival in stress conditions (oxidation, hyperthermia and starvation). However, the fertility of LM and HM pectins treated flies decreased. The treatment of the imagoes with LH and HM pectins induced the activation of whole-body expression of genes involved in DNA repair (D-GADD45, mei-9, spn-B), apoptosis (wrinkled/hid) and heat shock response (hsp70Aa). In contrast, the expression of proinflammatory PARP-1 gene decreased. In the intestines LH and HM pectins induced the mRNA expression of the NF-κB-dependent antimicrobial genes Defensin, Drosomycin and Metchnikowin. These results indicate that the observed lifespan-extending effect of the LM pectins may be mediated by intracellular pathways that involve NF-κB signalling and activation of stress resistance genes.

Effects of Methyl Donor Diets on Incisional Pain in Mice

BackgroundDietary supplementation with methyl donors can influence the programming of epigenetic patterns resulting in persistent alterations in disease susceptibility and behavior. However, the dietary effects of methyl donors on pain have not been explored. In this study, we evaluated the effects of dietary methyl donor content on pain responses in mice.MethodsMale and female C57BL/6J mice were treated with high or low methyl donor diets either in the perinatal period or after weaning. Mechanical and thermal nociceptive sensitivity were measured before and after incision.ResultsMice fed high or low methyl donor diets displayed equal weight gain over the course of the experiments. When exposed to these dietary manipulations in the perinatal period, only male offspring of dams fed a high methyl donor diet displayed increased mechanical allodynia. Hindpaw incision in these animals caused enhanced nociceptive sensitization, but dietary history did not affect the duration of sensitization. For mice exposed to high or low methyl donor diets after weaning, no significant differences were observed in mechanical or thermal nociceptive sensitivity either at baseline or in response to hindpaw incision.ConclusionsPerinatal dietary factors such as methyl donor content may impact pain experiences in later life. These effects, however, may be specific to sex and pain modality.

Determination of methyl mercury in humic-rich natural water samples using N2-distillation with isotope dilution and on-line purge and trap GC-ICP-MS

In this study a method for the determination of low methyl mercury (CH3Hg+) concentrations in non-filtered humic-rich natural water samples using an ethylation-purge and trap with isotope dilution GC-ICP-MS was developed. Purge and trap system was connected on-line to GC which was then coupled to ICP-MS with a simple non-heated in-house made interface. Samples analyzed in this study contained high amounts of dissolved organic matter (16–83mg DOC L−1) which is known to interact strongly with mercury affecting the ethylation efficiency. Thus, prior to instrumental determination CH3Hg+ was separated from the interfering matrix using a nitrogen-assisted distillation. Isotopically enriched spike was added to samples prior to distillation to correct the incomplete analyte recovery during the whole analysis procedure. The method detection limit for a 20mL sample volume was 0.05ngL−1 (3σ). The method precision obtained by replicate analyses of natural water samples was found to be better than 10% (RSD). Since there is no certified reference material available for low-level CH3Hg+ in water, the accuracy of the method was verified by comparing the results with the results obtained with gas chromatography — cold vapor atomic fluorescence spectrometry (GC-CV-AFS) based on the EPA method 1630. The results obtained with the two different methods were in good agreement with each other (r2=0.87, n=25) and the method was successfully applied to non-filtered humic-rich natural waters.

Enhanced solubility and dissolution of simvastatin by HPMC-based solid dispersions prepared by hot melt extrusion and spray-drying method

The objective of this study was to use low viscosity grade hydroxypropyl methyl cellulose (Methocel® E3 LV and Methocel® E5 LV) to enhance the solubility and dissolution of poorly water soluble drug simvastatin (SIM). Two different technologies, hot melt extrusion and spray drying were employed. Characterization of hot melt extrudes and spray dried samples was done by Fourier-transform infrared spectroscopy, differential scanning calorimetry, X-ray diffraction studies and scanning electron microscopy. The result of the study showed the conversion of crystalline form drug into amorphous form indicating increase in dissolution rate and solubility of SIM.

Partitioning of [Methyl-3H]Methionine to Methylated Products and Protein Is Altered during High Methyl Demand Conditions in Young Yucatan Miniature Pigs

Methionine is the main source of methyl groups that are partitioned to synthesize various methylated products including creatine, phosphatidylcholine (PC), and methylated DNA. Whether increased methylation of 1 product can divert methionine from protein synthesis or other methylation products was the aim of this experiment. We used an excess of guanidinoacetate (GAA) to synthesize creatine to create a higher demand for available methyl groups in normal-weight (NW) (n = 10) and intrauterine growth–restricted (IUGR) (n = 10) piglets. Anesthetized piglets (15–18 d old) were intraportally infused with either GAA or saline for 2 h. A bolus of L-[methyl-3H]methionine was intraportally infused at 1 h, and hepatic metabolites were analyzed for methyl-3H incorporation 1 h later. Overall, 50–75% of label was recovered in creatine and PC with negligible amounts in DNA. In both NW and IUGR piglets, excess GAA led to an ∼80–120% increase in methyl incorporation into creatine (P < 0.05) with a concomitant decrease by ∼75–85% in methyl incorporation into PC (P < 0.05) as well as a 40% decrease in methyl incorporation into protein (P < 0.05), suggesting methyl groups were limited for PC synthesis and that methionine was diverted from protein synthesis. Compared with NW piglets, IUGR piglets had lower methyl incorporation into PC (P < 0.05), but not DNA or protein, suggesting IUGR affects methyl metabolism and could potentially impact lipid metabolism. The partitioning of methionine is sensitive to methyl supply in neonates, which has implications in infant diet composition and growth.

Effects of Incomplete Transesterification Reaction of Palm Oil Biodiesel on Fuel Quality and Engine Performance

This study investigates how an incomplete tranesterification reaction influences the parameters of quality standards of the produced biodiesel engine performance and exhausts. The parameters evaluated include viscosity, cloud point, acid number and heating value. Biodiesels produced from palm oil were examined in terms of engine performance, where the 3-liter engine with a 4 cylinders 4 strokes, was used. The proportion of methyl ester in biodiesel was varied by adding appropriate amounts of triglyceride. Properties of biodiesel with the methyl ester between 75% and 96.8% by mass were tested against the standard diesel. The engine performance and thermal efficiency when using biodiesels of different qualities were determined under the operating engine speed range between 1,800 and 4,000 rpm. It was found that while the cloud point was raised with methyl ester content the viscosity was decreased. In terms of engine performance, greater proportion of methyl ester provides greater fuel conversion efficiency as well as specific fuel consumption rate. Incomplete conversion of triglyceride to methyl ester, which led to lower methyl ester content, significantly affected the engine performance and emissions. In overall, biodiesel with higher methyl ester content provided better engine performance and exhaust quality.

Histological analysis of cells and matrix mineralization of new bone tissue induced in rabbit femur bones by Mg–Zr based biodegradable implants

The biological efficacy of bone inducing implant materials in situ can be assessed effectively by performing histological analysis. We studied the peri-implant bone regeneration around two types of biodegradable magnesium–zirconium alloys, Mg–5Zr and Mg–Zr–2Sr, using histological, histochemical and immunohistochemical methods in the femur of New Zealand White strain rabbits. Our study includes three animal groups: (a) Mg–5Zr, (b) Mg–Zr–2Sr and (c) control. In each group three animals were used and in groups ‘a’ and ‘b’ the respective alloys were implanted in cavities made at the distal ends of the femur; control animals were left without implants to observe natural bone healing. Qualitative assessment of the cellularity and matrix mineralization events of the newly formed bone tissue was done at three months after implantation by histological methods in methyl methacrylate embedded tissue without decalcifying the bone. Quantitative mineral content and density of the new bone (NB) were evaluated by the statistical analysis of dual energy X-ray absorptiometry (DXA) data obtained from three animals in each experimental group. Based on our analysis we conclude that Mg–Zr–2Sr alloy showed better osseointegration of the newly formed bone with the implant surface. Our methodology of studying peri-implant osteoinduction of degradable implants using low temperature methyl methacrylate embedding resin can be useful as a general method for determining the bio-efficacy of implant materials.

Effects of single and repeated in vitro exposure of three forms of parabens, methyl-, butyl- and propylparabens on the proliferation and estradiol secretion in MCF-7 and MCF-10A cells

BackgroundHere, we analyzed the dose- (0.2, 2, 20, 200nM or 2μM) and time- (48, 96, 144 and 196h) dependent activity of a single or repeated exposure of methyl-, butyl- and propylparaben on the proliferation of MCF-7 human breast cancer cells and MCF-10A human breast epithelial cells. Additionally, the effect on estradiol secretion, gene and protein expression of aromatase (CYP19A1) was investigated. MethodsCell proliferation was determined by AlamarBlue assay, and estradiol secretion by ELISA kits. Gene and protein expression of CYP19A1 was measurement using real time PCR and western blot, respectively. ResultsStimulatory effect of a single exposure of all doses of tested parabens and time dependent effect of repeated exposure to methylparaben, propylparaben and butylparaben, the same as that of 17β-estradiol, on proliferation of MCF-7 cells was observed. Only at low doses methyl- and butylparabens increased MCF-10A cells proliferation after single exposure, but no effect of repeated exposure was noted. Exposure at low doses of all of the parabens significantly increased 17-β estradiol (E2) secretion in MCF-7 cells but had the opposite effect on MCF-10A cells. It was correlated with gene and protein expression of CYP19A1 in MCF-7 and MCF-10 cells. ConclusionsIn summary, present study indicates a different mechanism of proliferative action of parabens in investigated cell lines. In MCF-7 breast cancer cell line it is probably due to stimulatory action on estradiol secretion and aromatase activity. In MCF-10Aby an unknown mechanism, independent on stimulatory action on estradiol section, which requires further investigation.

Dietary methyl content regulates opioid responses in mice

BackgroundLarge interindividual differences in clinical responses to opioids and the variable susceptibility to abuse of this class of drugs make their use problematic. We lack a full understanding of the factors responsible for these differences. Dietary factors including methyl donor content have been noted to alter multiple physiological and behavioral characteristics of laboratory animals. The purpose of this research was to determine the effects of dietary methyl donor content on opioid responses in mice.MethodsGroups of male C57BL/6J mice were treated with high and low methyl donor diets either in the perinatal period or after weaning. Analgesic responses to morphine, as well as tolerance, opioid-induced hyperalgesia, and physical dependence were assessed.ResultsMice fed high and low methyl donor diets showed equal weight gain over the course of the experiments. Exposure to a high methyl donor diet in the perinatal period enhanced physical dependence. Dietary methyl donor content also altered analgesic responses to low doses of morphine when the dietary treatments were given to the mice after weaning. Opioid-induced hyperalgesia was unaltered by dietary methyl donor content.ConclusionHigh and low methyl donor diet treatment has selective effects on opioid responses depending on the timing of exposure. These findings suggest that examination of DNA methylation patterns in specific brain regions linked to opioid analgesia and dependence may provide specific explanations for dietary effects on opioid responses.

The Missing Member of the Partially O-Alkylated Resorcinarene Family: Synthesis and Conformation of Methyl Tetramethoxy Resorcinarene

An improved Lewis acid catalyzed synthesis method for methyl tetramethoxy resorcinarene is described, which produced the missing lower rim methyl derivative of this partially O-alkylated resorcinarene family. Structural characterization by means of variable temperature NMR experiments and single crystal X-ray diffraction studies furthermore revealed that the resorcinarene core adopts different conformations in the solid state and in solution.

C112 低級脂肪酸メチルエステルとエタノールの混合燃料を用いた火花点火機関の性能(一般講演(4))

This study investigates the suitability of lower fatty-acid methyl esters from plants oils in port-injected SI engines. Caprylic acid (C8:0) methyl ester (CaME) that is the lowest fatty acid in a palm kernel oil was selected as a test fuel. CaME was blended into ethanol to obtain the adequate vaporability for SI engines. The experiments were conducted for various fuel blend-ratios, engine loads, and ignition timings under the stoichiometric condition. The results show that the engine performance and exhaust emissions with CaME blend up to 40vol% are almost equivalent to those with ethanol fuel.

Spatial and Temporal Assessment of Mercury and Organic Matter in Thermokarst Affected Lakes of the Mackenzie Delta Uplands, NT, Canada

We examined dated sediment cores from 14 thermokarst affected lakes in the Mackenzie Delta uplands, NT, Arctic Canada, using a case-control analysis to determine how retrogressive thaw slump development from degrading permafrost affected the delivery of mercury (Hg) and organic carbon (OC) to lakes. We show that sediments from the lakes with retrogressive thaw slump development on their shorelines (slump-affected lakes) had higher sedimentation rates and lower total Hg (THg), methyl mercury (MeHg), and lower organic carbon concentrations compared to lakes where thaw slumps were absent (reference lakes). There was no difference in focus-corrected Hg flux to sediments between reference lakes and slump-affected lakes, indicating that the lower sediment Hg concentration in slump-affected lakes was due to dilution by rapid inorganic sedimentation in the slump-affected lakes. Sedimentation rates were inversely correlated with THg concentrations in sediments among the 14 lakes considered, and explained 68% of the variance in THg concentration in surface sediment, further supporting the dilution hypothesis. We observed higher S2 (algal-derived carbon) and particulate organic carbon (POC) concentrations in sediment profiles from reference lakes than in slump lakes, likely because of dilution by inorganic siliciclastic matter in cores from slump-affected lakes. We conclude that retrogressive thaw slump development increases inorganic sedimentation in lakes, and decreases concentrations of organic carbon and associated Hg and MeHg in sediments.

Preparation and characterization of hydroxypropyl methyl cellulose films containing stable BCS Class II drug nanoparticles for pharmaceutical applications

The design and feasibility of a simple process of incorporating stable nanoparticles into edible polymer films is demonstrated with the goal of enhancing the dissolution rate of poorly water soluble drugs. Nanosuspensions produced from wet stirred media milling (WSMM) were transformed into polymer films containing drug nanoparticles by mixing with a low molecular weight hydroxylpropyl methyl cellulose (HPMC E15LV) solution containing glycerin followed by film casting and drying. Three different BCS Class II drugs, naproxen (NPX), fenofibrate (FNB) and griseofulvin (GF) were studied. The influence of the drug molecule on the film properties was also investigated. It was shown that film processing methodology employed has no effect on the drug crystallinity according to X-ray diffraction (XRD) and Raman spectroscopy. Differences in aggregation behavior of APIs in films were observed through SEM and NIR chemical imaging analysis. NPX exhibited the strongest aggregation compared to the other drugs. The aggregation had a direct effect on drug content uniformity in the film. Mechanical properties of the film were also affected depending on the drug–polymer interaction. Due to strong hydrogen bonding with the polymer, NPX exhibited an increase in Young's Modulus (YM) of approximately 200%, among other mechanical properties, compared to GF films. A synergistic effect between surfactant/polymer and drug/polymer interactions in the FNB film resulted in an increase of more than 600% in YM compared to the GF film. The enhancement in drug dissolution rate of films due to the large surface area and smaller drug particle size was also demonstrated.

Mucoadhesion evaluation of polysaccharide gels for vaginal application by using rheological and indentation measurements

The influence of hyaluronic acid (HA) and fructooligosaccharides (FOS) addition on low methyl pectin (LMP) gelation has been investigated in order to produce adhesive gel-based microparticles suitable for the development of a vaginal delivery system of pro- and prebiotics. First, dynamic rheological measurements were performed on LMP/Ca2+ gels with or without FOS and HA in presence or not of porcine stomach mucins. This rheological method is known to translate the interactions between polymer and mucins and then simulate the polymer bioadhesion potential. Nevertheless, as this method is disputed, in vitro and ex vivo indentation test measurements were also achieved in order to correlate the results obtained. Despite some different results, the overall tendency indicates that addition of HA and FOS enhanced the mucoadhesive properties of LMP gels. Moreover, gel-based microparticles obtained according to an emulsification/gelation method and composed by LMP 3% (w/v), FOS 5% (w/v) and HA 0.5% (w/v) displayed a mucoadhesive potential adapted to vaginal delivery system.

Pre-Screening for Low Methyl Guanine Methyltransferase (MGMT) Expression Results in High Response Rates to Temozolomide (TMZ) Therapy in AML and MDS Patients.

Abstract 422 Introduction:Many patients with acute myeloid leukemia (AML) and high-risk myelodysplasia (MDS) are not suitable candidates for standard induction therapy, and newer treatment approaches are needed. TMZ anti-tumor activity is attributed to methylation of DNA, leading to the formation of O6-methylguanine that eventually leads to apoptosis. Expression of MethylGuanine DNA MethylTransferase (MGMT) restores normal guanine, decreasing DNA alkylation and thus anti-tumor activity of TMZ. Brandwein et al. (Leukemia 2007;21:821–4) previously demonstrated that response to TMZ in AML patients could be correlated with low MGMT expression. Thus MGMT expression prescreening could be used to identify patients more likely to respond to TMZ and provide an alternative for patients who are not candidates for standard induction therapy. Methods:We conducted a prospective multicenter study of patients with previously untreated AML and high risk MDS who were not candidates for standard induction therapy. Patient selection was based on MGMT expression as determined by Western blot in bone marrow or peripheral blood. Screening was performed by comparing the expression ratio between MGMT and b-actin protein levels. Patients with a ratio <0.25 were eligible to receive TMZ therapy 200 mg/m2/day × 7 days. Patients achieving a complete response (CR) could receive up to 12 monthly cycles of temozolomide 200 mg/m2/day × 5 days. Partial responders received a modified schedule of temozolomide 100 mg/m2/day × 21 days. Results:MGMT expression was tested in 188 patients; median age was 75 years old (range 46–94 years);62% were male. Primary diagnoses were AML (86%) and MDS (14%). Low or weak MGMT expression was detected in 46% of patient that were therefore potential candidates for TMZ therapy. Responses were evaluated in 42 patients, and were divided into 4 categories: Complete (CR/CRp), Morphologic Leukemia-Free State (MLFS), Partial (PR) Minimal (MR). Response was observed in 74% of cases including 29% CR, 10% MLFS, 19% PR and 17% MR. Prognostic factors associated with a higher response rate to temozolomide included MDS presentation, ECOG PS 0 and favorable/standard cytogenetic risk group. Induction and post-remission cycles were well-tolerated and most patients could be successfully treated on an outpatient basis.Patient who reached CR/CRp had a significantly longer median survival (>18 months) compared to those who reached MLFS, PR and MR (5.6 months). Median duration of therapy for patients reaching CR/CRp was 255 days and a majority (80%) became transfusion independent. Grade 3 and 4 toxicities were rare with the most common being fatigue (17%) and diarrhea (6%). Discussion:Pre-selection of patients based on MGMT expression level was associated with a higher response rate to TMZ as compared to previously reported unselected patients. Complete response was associated with increased survival and treatment had a favorable toxicity profile even in frail elderly patients. Targeted therapy with TMZ is feasible in patients with low MGMT expression and represents a new option for AML and MDS patients who are not candidate for standard induction therapy. Disclosures:Brandwein:Merck: Research Funding. Off Label Use: Temozolomide therapy for AML and MDS. Kassis:Merck: Research Funding. Leber:Merck: Research Funding. Howson-Jan:Merck: Research Funding. Minden:Merck: Research Funding. Galarneau:Merck: Employment. Pouliot:Merck: Employment.

Kinetic Modeling of Ethane Pyrolysis at High Conversion

The primary objective of this study is to develop an improved first-principle-based mechanism that describes the molecular weight growth kinetics observed during ethane pyrolysis. A proper characterization of the kinetics of ethane pyrolysis is a prerequisite for any analysis of hydrocarbon pyrolysis and oxidation. Flow reactor experiments were performed with ~50/50 ethane/nitrogen mixtures with temperatures ranging from 550 to 850 °C at an absolute pressure of ~0.8 atm and a residence time of ~5 s. These conditions result in ethane conversions ranging from virtually no reaction to ~90%. Comparisons of predictions using our original mechanism to these data yielded very satisfactory results in terms of the temperature dependence of ethane conversion and prediction of the major products ethylene and hydrogen. However, there were discrepancies in some of the minor species concentrations that are involved in the molecular weight growth kinetics. We performed a series of CBS-QB3 analyses for the C(3)H(7), C(4)H(7), and C(4)H(9) potential energy surfaces to better characterize the radical addition reactions that lead to molecular weight growth. We also extended a published C(6)H(9) PES to include addition of vinyl to butadiene. The results were then used to calculate pressure-dependent rate constants for the multiple reaction pathways of these addition reactions. Inclusion of the unadjusted rate constants resulting from these analyses in the mechanism significantly improved the description of several of the species involved in molecular weight growth kinetics. We compare the predictions of this improved model to those obtained with a consensus model recently published as well as to ethane steam cracking data. We find that a particularly important reaction is that of vinyl addition to butadiene. Another important observation is that several radical addition reactions are partially equilibrated. Not only does this mean that reliable thermodynamic parameters are essential for an accurate model, but also that the reaction set describing molecular weight growth chemistry must include a final product that is sufficiently stable to shift the equilibrium toward this product despite the decrease in entropy that accompanies molecular weight growth. Another reaction, H addition to olefins, was found to inhibit molecular weight growth by leading to the production of a lower olefin plus methyl radicals.

Crystal Morphology as an Evidence of Supramolecular Organization in Adducts of 1,2-Bis(chloromercurio)tetrafluorobenzene with Organic Esters

Low melting organic esters, ethyl acetate (1), diethyl carbonate (2), methyl benzoate (3) and phenyl acetate (4), have been grown using the miniature zone melting in situ crystallization technique and their molecular and crystal structures have been determined. Co-crystallization of the esters 1–4 with Lewis acid 1,2-bis(chloromercurio)tetrafluorobenzene (II) resulted in three adducts with a ratio of organic to organometallic components of 1:1 (II·1, II·3, and II·4), and one complex with a corresponding ratio of 1:2 (2(II)·2). X-ray analysis revealed presence of supramolecular 1D chain associates in crystals of II·1 and II·3, which are similar to those found before in the crystal of individual II. The crystal structures of complexes 2(II)·2 and II·4 have demonstrated the presence of 2D layer supramolecular associates. Both 1D and 2D associates are stabilized mostly by strong Hg···Cl interactions between molecules of II, which in some cases are additionally strengthen via Hg···O, Hg···π, and π–π interactio...

Enhancing the lubricity of an environmentally friendly Swedish diesel fuel MK1

The lubricity of diesel fuel has a direct effect on the service life of the fuel injection equipment, and when alternative fuels are specified, is of vital importance. One such fuel is the Swedish diesel fuel, MK1 which contains low levels of sulphur and low lubricity. This paper investigated the use of ultra low sulphur diesel (ULSD) and fatty acid methyl esters derived from rapeseed (RME) blends to improve MK1 lubricity. Fuel lubricity was assessed using a high frequency reciprocating rig. The wear scar diameter of the ball specimen was measured using optical microscopy while the wear profile and surface roughness of the disc were analysed using a profilometer. Scanning electron microscopy with an energy dispersive spectrometer was used to evaluate the microscopic topography and chemical compositions of the surfaces. Results confirm that MK1 has poor lubricity when compared to other base fuels. Of the blended fuels, ULSD showed little improvement. However, a small percentage of RME improved the lubricity of both the pure MK1 and the blends. Analysis of the worn surfaces indicated that chemical compositions of MK1 did not adsorb and react as well when compared with those of ULSD, RME and selected blended fuels.

Lipoxygenase in Caragana jubata responds to low temperature, abscisic acid, methyl jasmonate and salicylic acid

Lipoxygenase (LOX) catalyses oxygenation of free polyunsaturated fatty acids into oxylipins, and is a critical enzyme of the jasmonate signaling pathway. LOX has been shown to be associated with biotic and abiotic stress responses in diverse plant species, though limited data is available with respect to low temperature and the associated cues. Using rapid amplification of cDNA ends, a full-length cDNA ( CjLOX) encoding lipoxygenase was cloned from apical buds of Caragana jubata, a temperate plant species that grows under extreme cold. The cDNA obtained was 2952 bp long consisting of an open reading frame of 2610 bp encoding 869 amino acids protein. Multiple alignment of the deduced amino acid sequence with those of other plants demonstrated putative LH2/ PLAT domain, lipoxygenase iron binding catalytic domain and lipoxygenase_2 signature sequences. CjLOX exhibited up- and down-regulation of gene expression pattern in response to low temperature (LT), abscisic acid (ABA), methyl jasmonate (MJ) and salicylic acid (SA). Among all the treatments, a strong up-regulation was observed in response to MJ. Data suggests an important role of jasmonate signaling pathway in response to LT in C. jubata.