7,035 research outputs found
Effects of niacin combination therapy with statin or bile acid resin on lipoproteins and cardiovascular disease.
No full textMolecular cloning and sequencing of the sodB gene from a heterocystous cyanobacterium Anabaena sp PCC 7120
No full textSuperoxide dismutase (Sod) plays an important role in all aerobic organisms. The sodB gene of a heterocystous cyanobacterium Anabaena sp. PCC 7120 was cloned and sequenced. The Sod protein is predicted to have 199 amino acids and a molecular mass of 22.5 kDa. Sequence comparison among SodB from cyanobacteria and chloroplasts revealed that the sodB gene indeed encodes an iron-Sod. Northern blot analysis showed that the sodB gene of Anabaena sp. PCC 7120 is transcribed as a single gene and its expression was up-regulated when the cells were subjected to a shift from a nitrogen repletion condition to a nitrogen depletion condition. (C) 2000 Elsevier Science B.V. All rights reserved.Biochemistry & Molecular BiologyBiophysicsSCI(E)8ARTICLE1-3248-252149
Expression of <i>hetN</i> during heterocyst differentiation and its inhibition of <i>hetR</i> up-regulation in the cyanobacterium <i>Anabaena</i> sp. PCC 7120
No full textThe <i>hetN</i> gene plays an important role in heterocyst differentiation and pattern formation. An immunoblotting study showed that the <i>hetN</i> gene in <i>Anabaena</i> sp. PCC 7120 was expressed in vegetative cells grown with combined nitrogen. After a switch to a medium without combined nitrogen, <i>hetN</i> expression first declined and was then followed by a rapid increase in its product, HetN, which was only present in mature heterocysts. HetN is located on both thylakoid membranes and plasma membranes as determined by immunoblotting using purified membranes. Overexpression of <i>hetN</i> completely prevented <i>hetR</i> up-regulation under nitrogen-deprivation conditions, suggesting that its role in pattern control may depend on its inhibition of <i>hetR</i> expression
Consideration of Interference Correlation Properties in a JD-CDMA Mobile Radio System with Coherent Receiver Antenna Diversity
No full textIn code division multiple access (CDMA) mobile radio systems, both intersymbol interference and multiple access interference arise which can be combatted by using Joint Detection (JD) techniques, to reduce the degradation in performance resulting from time variance, coherent receiver antenna diversity (CRAD) can be used. The application of JD techniques offers the possibility to exploit the knowledge of noise covariances at the receiver. If only intercell (cochannel) interference is considered, the noise covariances in the uplink receiver of a multiple receiver antenna CDMA mobile radio system depend mainly on the directions of arrival (DOAs) of the interfering signals and the receiver antenna placement. Therefore, if the interferer DOAs are known at the base station, these covariances could be estimated. In this thesis, a realistic model of the uplink of a JD CDMA mobile radio system with CRAD is described in which the above mentioned interference cancelling method is used. Simulation results according to this model are given and evaluated.Applied SciencesElectrical EngineeringTelecommunications and Traffic Control Systems Grou
FesM, a membrane iron-sulfur protein, is required for cyclic electron flow around photosystem I and photoheterotrophic growth of the cyanobacterium Synechococcus sp PCC 7002
No full textWhile it is known that cyclic electron flow around photosystem I is an important pathway of photosynthetic electron transfer for converting light energy to chemical energy, some components of cyclic electron flow remain to be revealed. Here, we show that fesM, encoding a novel membrane iron-sulfur protein, is essential to cyclic electron flow in the cyanobacterium Synechococcus sp. PCC 7002. The FesM protein is predicted to have a cAMP-binding domain, an NtrC- like domain, a redox sensor motif, and an iron- sulfur (4Fe-4S) motif. Deletion of fesM (fesM-D) led to an inability for Synechococcus cells to grow in the presences of glycerol and 3-(3,4-dichlorophenyl)-1,1-dimethylurea. Photoheterotrophic growth was restored by a complete fesM gene present on a replicable plasmid. A mutant fesM gene encoding a truncated FesM protein lacking the cAMP domain failed to restore the phenotype, suggesting this domain is important to the function of FesM. Measurements of reduction of P700(+) and the redox state of interphotosystem electron carriers showed that cells had a slower rate of respiratory electron donation to the interphotosystem electron transport chain, and cyclic electron flow around photosystem I in fesM-D was impaired, suggesting that FesM is a critical protein for respiratory and cyclic electron flow. Phosphatase fusion analysis showed that FesM contains nine membrane- spanning helices, and all functional domains of FesM are located on the cytoplasmic face of the thylakoid membranes.Plant SciencesSCI(E)EIPubMed5ARTICLE31586-159513
Dairy farmers’ perceptions toward the implementation of on-farm Johne’s disease prevention and control strategies
No full textmplementation of specific management strategies on dairy farms is currently the most effective way to reduce the prevalence of Johne’s disease (JD), an infectious chronic enteritis of ruminants caused by Mycobacterium avium subspecies paratuberculosis (MAP). However, dairy farmers often fail to implement recommended strategies. The objective of this study was to assess perceptions of farmers participating in a JD prevention and control program toward recommended practices, and explore factors that influence whether or not a farmer adopts risk-reducing measures for MAP transmission. Semi-structured interviews were conducted with 25 dairy farmers enrolled in a voluntary JD control program in Alberta, Canada. Principles of classical grounded theory were used for participant selection, interviewing, and data analysis. Additionally, demographic data and MAP infection status were collected and analyzed using quantitative questionnaires and the JD control program database. Farmers’ perceptions were distinguished according to 2 main categories: first, their belief in the importance of JD, and second, their belief in recommended JD prevention and control strategies. Based on these categories, farmers were classified into 4 groups: proactivists, disillusionists, deniers, and unconcerned. The first 2 groups believed in the importance of JD, and proactivists and unconcerned believed in proposed JD prevention and control measures. Groups that regarded JD as important had better knowledge about best strategies to reduce MAP transmission and had more JD risk assessments conducted on their farm. Although not quantified, it also appeared that these groups had more JD prevention and control practices in place. However, often JD was not perceived as a problem in the herd and generally farmers did not regard JD control as a “hot topic” in communications with their herd veterinarian and other farmers. Recommendations regarding how to communicate with farmers and motivate various groups of farmers according to their specific perceptions were provided to optimize adoption of JD prevention and control measures and thereby increase success of voluntary JD control programs
Estimating the influence of disruption on highway networks using GPS data
No full textIncidents, such as natural disasters, public events, and holidays, often cause problems to highways, even paralyze the operation of the whole networks, leading to a serious threat to travel efficiency and safety of the public. To provide better transport management and plans for emergencies, it is important to quickly and accurately identify such incidents and estimate their disruptive effects on the networks. To this end, a novel approach has been proposed in this paper, which is based on the Bayesian theory and thrice-standard-error principle while utilizing vehicle GPS data. Two important indicators, including traffic flows and congestion indexes, along with their change ratios, are built to detect the incidents and evaluate the extent of the disruption. The specific disrupted and detour roads are further determined. The proposed method has been tested using two real-world events in China, and the potential and effectiveness of this technique are demonstrated. With more and more vehicles being equipped with GPS devices worldwide, the designed method can be easily transferable to other countries, paving a way for the adoption of the approach for a more spatial-temporal sensitive highway network disruption analysis method that supports the establishment of a more resilient transport system for emergencies.This work was supported by the Science Fund for Creative Research Groups of the National Natural Science Foundation of China [Grant number 71621001]; National Key Research and Development Program of China [Grant number 2018YFB2101003]; and the National Natural Science Foundation of China [Grant number 72101022, 71871011 and 72091513]
Proteomic Analysis of the Effects of Shenzhu Tiaopi Granules on Model Rats with Type 2 Diabetes Mellitus
No full textJin-Dong Zhao,1– 3 Zhao-Hui Fang1– 3 1Department of Endocrinology Two, the First Affiliated Hospital of Anhui University of Chinese Medicine, Hefei, Anhui Province, 230031, People’s Republic of China; 2Center for Xin’an Medicine and Modernization of Traditional Chinese Medicine of IHM, the First Affiliated Hospital of Anhui University of Chinese Medicine, Hefei, Anhui Province, 230012, People’s Republic of China; 3Diabetes Institute, Anhui Academy Chinese Medicine, Hefei, 230012, People’s Republic of ChinaCorrespondence: Zhao-Hui Fang, Department of Endocrinology Two, the First Affiliated Hospital of Anhui University of Chinese Medicine, 117 Meishan Road, Hefei, Anhui Province, 230031, People’s Republic of China, Email [email protected]: Shenzhu Tiaopi granule (STG) has antidiabetic functions. Data-independent acquisition proteomic technology is an integral part of systems biology. Herein, proteomics was used to analyse the effects of STG on type 2 diabetes mellitus (T2DM) and the mechanism by which STG normalizes glucose metabolism.Methods: Goto-Kakizaki (GK) T2DM model (Mod) rats, aged 15– 16 weeks and with a fasting blood glucose (FBG) level of ≥ 11.1 mmol/L, were treated with metformin or STG for 12 weeks. Wistar rats aged 15– 16 weeks were included in the control (Con) group. Body weight, FBG, total cholesterol (TC), total triglyceride (TG) levels and low-density lipoprotein (LDL-C) levels were measured, and pathological observation, Western blot analysis and data-independent acquisition proteomics of the liver were performed.Results: Significant differences in FBG, TC, TG, LDL-C (p < 0.01) and pathological liver morphology were observed between the Mod group and Con group, whereas both metformin and STG normalized the glucose and lipid metabolism indicators (p < 0.05 or p < 0.01). In total, 5856 proteins were identified via proteomic analysis, 97 of which were significantly differentially expressed in the liver and affected fatty acid metabolism, unsaturated fatty acid biosynthesis, the peroxisome proliferator-activated receptor (PPAR) signalling pathway, pyruvate metabolism, and terpenoid backbone biosynthesis. Screening identified 10 target proteins, including perilipin‐2 (Plin2), pyruvate dehydrogenase kinase 4, farnesyl diphosphate synthase (Fdps) and farnesyl-diphosphate farnesyltransferase 1. Among these proteins, the key proteins were Plin2 and Fdps, which were found to be associated with the PPAR signalling pathway and terpenoid backbone biosynthesis via relationship networks. Plin2 and Fdps are closely related to hyperglycaemia. STG can downregulate Plin2 and upregulate Fdps (p < 0.01).Conclusion: STG ameliorated hyperglycaemia by significantly altering the expression of different proteins, especially Fdps and Plin2, in the livers of GK rats. These findings may reveal the potential of traditional Chinese medicine for treating T2DM.Keywords: type 2 diabetes mellitus, improving hyperglycaemia, proteomics, Fdps, Plin2, Shenzhu Tiaopi granul
Sulfonation of polyvinylidene difluoride resin and its application in extraction of restriction enzymes from DNA digestion solutions
No full textSulfonation of polyvinylidene difluoride (PVDF) resin was achieved by incubation of the resin with sulfuric acid at a moderately high temperature. The sulfonated PVDF (SPVDF) resin was studied for its ability to extract restriction enzymes from DNA digestion solutions. The SPVDF resin was effective in adsorbing restriction enzymes such as EcoRI and BamHI and the extraction procedure was easy and simple to perform. The adsorption depended upon the amount of the resin added. We found that 1 mg of the SPVDF resin could completely remove all restriction enzyme activity routinely used in DNA digestion within 2 min after its addition. Treatment of a digestion solution with the SPVDF resin did not change the reaction solution and the same digestion buffer could be used for another digestion of the same DNA with other enzymes. We also found that, in comparison with normal PVDF, the SPVDF resin adsorbed less DNA, resulting in less loss of DNA in the extraction step. The potential application of the SPVDF resin in other procedures of molecular cloning and enzyme purification is discussed
HetR homodimer is a DNA-binding protein required for heterocyst differentiation, and the DNA-binding activity is inhibited by PatS
No full textHetR plays a key role in regulation of heterocyst differentiation. When the Cys-48 residue of the HetR from Anabaena sp. PCC 7120 was replaced with an Ala residue, the mutant HetR (HetR<sub>C48A</sub>) could not dimerize, indicating that HetR forms a homodimer through a disulfide bond. The Anabaena strain C48, containing the hetRc48a gene, could not produce HetR homodimer and failed to form heterocyst. We show that HetR is a DNA-binding protein and that its homodimerization is required for the DNA binding. HetR binds the promoter regions of hetR, hepA, and patS, suggesting a direct control of the expression of these genes by HetR. We present evidence that shows that the up-regulation of patS and hetR depends on DNA binding by HetR dimer. The pentapeptide RGSGR, which is present at the C terminus of PatS and blocks heterocyst formation, inhibits the DNA binding of HetR and prevents hetR up-regulation
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