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31.
This paper builds on the past study of single-spike waves in one-dimensional integrate-and-fire networks to provide a framework for the study of waves with arbitrary (finite or countably infinite) collections of spike times. Based on this framework, we prove an existence theorem for single-spike traveling waves, and we combine analysis and numerics to study two-spike traveling waves, periodic traveling waves, and general infinite spike trains. For a fixed wave speed, finite-spike waves, periodic waves, and other infinite-spike waves may all occur, and we discuss the relationships among them. We also relate the waves considered analytically to waves generated in numerical simulations by the transient application of localized excitation.Key words or phrases:Traveling waves, Integrate-and-fire network, Excitatory synaptic coupling 相似文献
32.
Goettsch S Badea RA Mueller JW Wotzlaw C Schoelermann B Schulz L Rabiller M Bayer P Hartmann-Fatu C 《Journal of molecular biology》2006,361(3):436-449
TPST1 is a human tyrosylprotein sulfotransferase that uses 3'phosphoadenosine-5'phosphosulfate (PAPS) to transfer the sulfate moiety to proteins predominantly designated for secretion. To achieve a general understanding of the cellular role of human tyrosine-directed sulfotransferases, we investigated targeting, structure and posttranslational modification of TPST1. Golgi localisation of the enzyme in COS-7 and HeLa cells was visualised by fluorescence imaging techniques. PNGase treatment and mutational studies determined that TPST1 bears N-linked glycosyl residues exclusively at position Asn60 and Asn262. By alanine mutation of these asparagine residues, we could determine that the N-linked oligosaccharides do not have an influence on Golgi retention of TPST1. In concert with N and C-terminal flanking residues, the transmembrane domain of TPST1 was determined to act in targeting and retention of the enzyme to the trans-Golgi compartment. This domain exhibits a pronounced secondary structure in a lipid environment. Further in vivo FRET studies using the transmembrane domain suggest that the human tyrosylprotein sulfotransferase may be functional as homodimer/oligomer in the trans-Golgi compartment. 相似文献
33.
Nam Hoon Kim Juneyoung Lee Tae Joon Kim Nan Hee Kim Kyung Mook Choi Sei Hyun Baik Dong Seop Choi Rodica Pop-Busui Yousung Park Sin Gon Kim 《PloS one》2015,10(10)
Background
The association between body mass index (BMI) and mortality is not conclusive, especially in East Asian populations. Furthermore, the association has been neither supported by recent data, nor assessed after controlling for weight changes.Methods
We evaluated the relationship between BMI and all-cause or cause-specific mortality, using prospective cohort data by the National Health Insurance Service in Korea, which consisted of more than one million subjects. A total of 153,484 Korean adults over 30 years of age without pre-existing cardiovascular disease or cancer at baseline were followed-up until 2010 (mean follow-up period = 7.91 ± 0.59 years). Study subjects repeatedly measured body weight 3.99 times, on average.Results
During follow-up, 3,937 total deaths occurred; 557 deaths from cardiovascular disease, and 1,224 from cancer. In multiple-adjusted analyses, U-shaped associations were found between BMI and mortality from any cause, cardiovascular disease, and cancer after adjustment for age, sex, smoking status, alcohol consumption, physical activity, socioeconomic status, and weight change. Subjects with a BMI < 23 kg/m2 and ≥ 30 kg/m2 had higher risks of all-cause and cause-specific mortality compared with the reference group (BMI 23–24.9 kg/m2). The lowest risk of all-cause mortality was observed in subjects with a BMI of 25–26.4 kg/m2 (adjusted hazard ratio [HR] 0.86; 95% CI 0.77 to 0.97). In subgroup analyses, including the elderly and those with chronic diseases (diabetes mellitus, hypertension, and chronic kidney disease), subjects with a BMI of 25–29.9 kg/m2 (moderate obesity) had a lower risk of mortality compared with the reference. However, this association has been attenuated in younger individuals, in those with higher socioeconomic status, and those without chronic diseases.Conclusion
Moderate obesity was associated more strongly with a lower risk of mortality than with normal, underweight, and overweight groups in the general population of South Korea. This obesity paradox was prominent in not only the elderly but also individuals with chronic disease. 相似文献34.
35.
Usein CR Damian M Tatu-Chiţoiu D Căpuşă C Făgăraş R Mircescu G 《Roumanian archives of microbiology and immunology》2003,62(3-4):137-154
Formally included in the larger category of extraintestinal pathogenic Escherichia coli (ExPEC), the uropathogenic E. coli remains the most frequent cause of urinary tract infection (UTI), an important endemic health problem. The genomic DNA of E. coli urinary isolates from adults diagnosed with urinary tract infections and of E. coli fecal isolates from healthy subjects was analysed by PCR for the presence of virulence factor encoding genes pap, sfa/foc, afa, hly and cnf and by field inversion gel electrophoresis (FIGE) fingerprinting of XbaI DNA macrorestriction fragments. The aim was to obtain more detailed microbiological data regarding the community circulating strains in respect of their virulence potential and genetic relatedness. Almost 70% of the urinary strains carried at least one of the target virulence genes, and only 35.5% of the fecal E. coli strains were positive in the PCR screening. Taking into account the virulence genotypes exhibited, a part of the strains isolated from the urinary tract could be defined as belonging to the ExPEC pathotype. A unique FIGE profile was obtained for each of the selected isolates and the dendrogram generated by Taxotron software package analysis suggested a polyclonal population of potential uropathogenic strains clustered into 14 groups of only 60% similarity. For better understanding the epidemiology of UTIs, diseases commonly caused by such a heterogeneous species like E. coli, molecular analysis methods could be essential due to their increased power of identification and fingerprinting. 相似文献
36.
Stefana Petrescu Stefan A. Hulea Rodica Stan Dorina Avram Victoria Herlea 《Biotechnology letters》1992,14(1):1-6
Summary The bioconversion of D-galacturonic acid to L-ascorbic acid was demonstrated in a new yeast strain isolated from the Japanese Crystal. Both intact cells and a crude mitochondrial extract yielded L-ascorbic acid when D-galacturonic acid was present. 相似文献
37.
Carolina Constantin Andreea‐Roxana Lupu Tudor Emanuel Fertig Mihaela Gherghiceanu Sevinci Pop Rodica‐Mariana Ion Monica Neagu 《Journal of cellular and molecular medicine》2019,23(2):1086-1094
Phthalocyanines (Pc) and their metallated derivatives are strongly considered for photodynamic therapy (PDT) possessing unique properties as possible new photosensitizers (PS). We have used toxicological assessments, real‐time monitoring of cellular impedance, and imagistic measurements for assessing the in vitro dark toxicity and PDT efficacy of Ga(III)‐Pc in SHSy5Y neuroblastoma cells. We have established the non‐toxic concentration range of Ga(III)‐Pc, a compound which shows a high intracellular accumulation, with perinuclear distribution in confocal microscopy. By choosing Ga(III)Pc non‐toxic dose, we performed in vitro experimental PDT hampering cellular proliferation. Our proposed Ga(III)‐Pc could complete a future PS panel for neuroblastoma alternate therapy. 相似文献
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39.
Maria Crisan Marian Taulescu Diana Crisan Rodica Cosgarea Alina Parvu Cornel C?toi Tudor Drugan 《PloS one》2013,8(10)
The glycation process is involved in both the intrinsic (individual, genetic) and extrinsic (ultraviolet light, polution and lifestyle) aging processes, and can be quantified at the epidermal or dermal level by histological, immunohistochemical (IHC), or imagistic methods. Our study is focused on a histological and immunohistological comparison of sun-protected regions versus sun-exposed regions from different age groups of skin phototype III subjects, related to the aging process. Skin samples collected from non-protected and UV protected regions of four experimental groups with different ages, were studied using histology and IHC methods for AGE-CML [N(epsilon)-(carboxymethyl)lysine]. A semi-quantitative assessment of the CML expression in the microvascular endothelium and dermal fibroblasts was performed. The Pearson one-way ANOVA was used to compare data between the groups. In the dermis of sun-exposed skin, the number and the intensity of CML positive cells in both fibroblasts and endothelial cells (p<0.05) was higher compared to sun-protected skin, and was significantly increased in older patients. The sun-exposed areas had a more than 10% higher AGE-CML score than the protected areas. No statistically significant correlation was observed between the histological score and the IHC expression of CML. We concluded that in healthy integument, the accumulation of final glycation products increases with age and is amplified by ultraviolet exposure. The study provides new knowledge on differences of AGE-CML between age groups and protected and unprotected areas and emphasizes that endothelium and perivascular area are most affected, justifying combined topical and systemic therapies. 相似文献
40.
Rodica Gilca Geneviève Deceuninck Brigitte Lefebvre Raymond Tsang Rachid Amini Vladimir Gilca Monique Douville-Fradet France Markowski Philippe De Wals 《PloS one》2012,7(11)