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71.
Footprint analysis of gait using a pressure sensor system. 总被引:12,自引:0,他引:12
Ekaterina B Titianova Plamen S Mateev Ina M Tarkka 《Journal of electromyography and kinesiology》2004,14(2):275-281
The purpose of this study was to investigate if the detailed pressure data of the footprints of normal gait add essential information to the spatio-temporal variables of gait. The gait of 62 healthy adult subjects was investigated using GAITRite pressure sensor system. Each footprint was divided into 12 equal trapezoids and after that the hindfoot, midfoot and forefoot analysis was developed. A typical activation pattern of the sensors with two peaks of active area and peak pressure distribution during normal walking was obtained. The first peak reflected the heel strike, and the second peak reflected push-off at the end of the stance phase. The lowest pressure values were in the midfoot, where the lateral part of the foot activated sensors more than the medial part. The footprint patterns of right and left legs were symmetrical and corresponded with the symmetry found in the spatio-temporal variables of gait. The variability for the active area and the peak pressure were more pronounced for the lateral part of the midfoot and a smaller variation was seen in areas with concentrated observations (e.g. 1st, 2nd and 5th lateral trapezoids). Increasing active area in the forefoot was associated with decreasing pressure sensor activity in the midfoot. The footprint patterns identified the symmetry between the legs and at the same time revealed the velocity performance. 相似文献
72.
73.
Plamen L. Simeonov Jaime Gomez-Ramirez Pridi Siregar 《Progress in biophysics and molecular biology》2013
This paper summarizes the results in Integral Biomathics obtained to this moment and provides an outlook for future research in the field. 相似文献
74.
Ludmila Ivanova Plamen Dimitrov Dora Ovcharova Jocilyn Dellava Daniel J. Hoffman 《Economics & Human Biology》2006,4(3):383-397
Major economic transitions typically entail changes in the availability of and purchasing power for different types of foods leading to long-term changes in the composition of the diet. Bulgaria, a former Eastern Bloc country, underwent a difficult and protracted transition from a centralized to market economy with acute economic crises and a much slower recovery of income levels than in Poland, the Czech Republic, and Hungary. Using annual data from the Bulgarian National Household Survey, we study changes in the reported consumption of major foods (excluding alcoholic drinks) and their constituent macronutrients from 1985 to 2002, examining also the differences in dietary patterns between the period prior to and following the transition. The consumption of most major food items decreased, resulting in a fall in per capita energy consumption of 429 kcal/day (1.80 MJ/d), following the economic transition of 1991. As expected, the consumption of foods that were more expensive per unit of energy decreased greater than cheaper foods, -34% for animal products and -19% for visible fats, but only -10% for carbohydrates. These changes are related to the changes in income and market prices as well as the general negative trend in economic growth and hyperinflation in the mid-1990s. Thus, Bulgaria experienced a decrease in food consumption without significant changes in the dietary pattern following the economic transition of 1991. The fact that part of this decline may be attributed to continued economic challenges suggests that future transitions in the diet may be expected as economic development proceeds. 相似文献
75.
Lei Cheng Kaustubh Khedekar Morteza Rezaei Talarposhti Andrea Perego Michael Metzger Saravanan Kuppan Sarah Stewart Plamen Atanassov Nobumichi Tamura Nathan Craig Iryna V. Zenyuk Christina M. Johnston 《Liver Transplantation》2020,10(28)
Pt catalysts in polymer electrolyte fuel cells degrade heterogeneously as the catalyst particles are exposed to local variations throughout the catalyst layer during operation. State‐of‐the‐art analytical techniques for studying degradation of Pt catalysts do not possess fine spatial resolution to elucidate such non‐uniform degradation behavior at a large electrode level. A new methodology is developed to spatially resolve and quantify the heterogeneous Pt catalyst degradation over a large area (several cm2) of aged MEAs based on synchrotron X‐ray microdiffraction. PEFC single cells are aged using voltage cycling as an accelerated stress test and the degradation heterogeneity at a micrometer length scale is visualized by mapping Pt catalyst particle size after voltage cycling. It is demonstrated in detail that the Pt catalyst particle size growth is non‐uniform and follows the flow field geometry. The Pt particle size growth is greater in the area under the flow field land, while it is minimal in the area under the flow field channel. Additional non‐uniformity is observed with the Pt particle size increasing more rapidly at the air outlet area than the Pt particle size at the inlet area. 相似文献
76.
Shiou-chi Chang Bogdan I. Fedeles Jie Wu James C. Delaney Deyu Li Linlin Zhao Plamen P. Christov Emily Yau Vipender Singh Marco Jost Catherine L. Drennan Lawrence J. Marnett Carmelo J. Rizzo Stuart S. Levine F. Peter Guengerich John M. Essigmann 《Nucleic acids research》2015,43(11):5489-5500
Etheno DNA adducts are a prevalent type of DNA damage caused by vinyl chloride (VC) exposure and oxidative stress. Etheno adducts are mutagenic and may contribute to the initiation of several pathologies; thus, elucidating the pathways by which they induce cellular transformation is critical. Although N2,3-ethenoguanine (N2,3-εG) is the most abundant etheno adduct, its biological consequences have not been well characterized in cells due to its labile glycosidic bond. Here, a stabilized 2′-fluoro-2′-deoxyribose analog of N2,3-εG was used to quantify directly its genotoxicity and mutagenicity. A multiplex method involving next-generation sequencing enabled a large-scale in vivo analysis, in which both N2,3-εG and its isomer 1,N2-ethenoguanine (1,N2-εG) were evaluated in various repair and replication backgrounds. We found that N2,3-εG potently induces G to A transitions, the same mutation previously observed in VC-associated tumors. By contrast, 1,N2-εG induces various substitutions and frameshifts. We also found that N2,3-εG is the only etheno lesion that cannot be repaired by AlkB, which partially explains its persistence. Both εG lesions are strong replication blocks and DinB, a translesion polymerase, facilitates the mutagenic bypass of both lesions. Collectively, our results indicate that N2,3-εG is a biologically important lesion and may have a functional role in VC-induced or inflammation-driven carcinogenesis. 相似文献
77.
Gibbons HS Broomall SM McNew LA Daligault H Chapman C Bruce D Karavis M Krepps M McGregor PA Hong C Park KH Akmal A Feldman A Lin JS Chang WE Higgs BW Demirev P Lindquist J Liem A Fochler E Read TD Tapia R Johnson S Bishop-Lilly KA Detter C Han C Sozhamannan S Rosenzweig CN Skowronski EW 《PloS one》2011,6(3):e17836
Background
Despite the decades-long use of Bacillus atrophaeus var. globigii (BG) as a simulant for biological warfare (BW) agents, knowledge of its genome composition is limited. Furthermore, the ability to differentiate signatures of deliberate adaptation and selection from natural variation is lacking for most bacterial agents. We characterized a lineage of BGwith a long history of use as a simulant for BW operations, focusing on classical bacteriological markers, metabolic profiling and whole-genome shotgun sequencing (WGS).Results
Archival strains and two “present day” type strains were compared to simulant strains on different laboratory media. Several of the samples produced multiple colony morphotypes that differed from that of an archival isolate. To trace the microevolutionary history of these isolates, we obtained WGS data for several archival and present-day strains and morphotypes. Bacillus-wide phylogenetic analysis identified B. subtilis as the nearest neighbor to B. atrophaeus. The genome of B. atrophaeus is, on average, 86% identical to B. subtilis on the nucleotide level. WGS of variants revealed that several strains were mixed but highly related populations and uncovered a progressive accumulation of mutations among the “military” isolates. Metabolic profiling and microscopic examination of bacterial cultures revealed enhanced growth of “military” isolates on lactate-containing media, and showed that the “military” strains exhibited a hypersporulating phenotype.Conclusions
Our analysis revealed the genomic and phenotypic signatures of strain adaptation and deliberate selection for traits that were desirable in a simulant organism. Together, these results demonstrate the power of whole-genome and modern systems-level approaches to characterize microbial lineages to develop and validate forensic markers for strain discrimination and reveal signatures of deliberate adaptation. 相似文献78.
79.
Maria Kahlert Martyn Kelly Raino-Lars Albert Salomé F. P. Almeida Tomáš Bešta Saúl Blanco Michel Coste Luc Denys Luc Ector Markéta Fránková Daša Hlúbiková Plamen Ivanov Bryan Kennedy Petr Marvan Adrienne Mertens Juha Miettinen Joanna Picinska-Fałtynowicz Juliette Rosebery Elisabet Tornés Sirje Vilbaste Andrea Vogel 《Hydrobiologia》2012,680(1):109-124
The heterogeneity of oxygen distribution in a Hediste diversicolor burrow environment was investigated in a laboratory experiment using a 6-mm thick tank equipped with oxygen planar optodes.
The two-dimensional oxygen distribution in a complete burrow was monitored every 2 min for 4 h. Oxygen concentrations fluctuated
over a scale of minutes in the burrow lumen and wall (up to 2 mm) reflecting the balance between worm ventilation activity
and oxygen consumption. The magnitude of the three surrounding micro-horizons (oxic, oscillating and anoxic) induced by the
intermittent worm ventilation was spatially and temporally variable within the structure. Oxygen variations appeared to be
controlled by distance from the sediment–water interface and the direction of water circulation. Moreover, there was an apparent
‘buffer effect’, induced by the proximity to the overlying water, which reduced the variations of lumen and wall oxygen in
the upper part of the structure. These results highlight the heterogeneous distribution and dynamics of oxygen associated
with H. diversicolor burrows and ventilation activity. They also highlight the necessity of integrating this complexity into the current burrow-base
models in order to estimate the ecological importance of burrowing species in coastal ecosystems. 相似文献
80.
Bierhaus A Fleming T Stoyanov S Leffler A Babes A Neacsu C Sauer SK Eberhardt M Schnölzer M Lasitschka F Neuhuber WL Kichko TI Konrade I Elvert R Mier W Pirags V Lukic IK Morcos M Dehmer T Rabbani N Thornalley PJ Edelstein D Nau C Forbes J Humpert PM Schwaninger M Ziegler D Stern DM Cooper ME Haberkorn U Brownlee M Reeh PW Nawroth PP 《Nature medicine》2012,18(6):926-933
This study establishes a mechanism for metabolic hyperalgesia based on the glycolytic metabolite methylglyoxal. We found that concentrations of plasma methylglyoxal above 600 nM discriminate between diabetes-affected individuals with pain and those without pain. Methylglyoxal depolarizes sensory neurons and induces post-translational modifications of the voltage-gated sodium channel Na(v)1.8, which are associated with increased electrical excitability and facilitated firing of nociceptive neurons, whereas it promotes the slow inactivation of Na(v)1.7. In mice, treatment with methylglyoxal reduces nerve conduction velocity, facilitates neurosecretion of calcitonin gene-related peptide, increases cyclooxygenase-2 (COX-2) expression and evokes thermal and mechanical hyperalgesia. This hyperalgesia is reflected by increased blood flow in brain regions that are involved in pain processing. We also found similar changes in streptozotocin-induced and genetic mouse models of diabetes but not in Na(v)1.8 knockout (Scn10(-/-)) mice. Several strategies that include a methylglyoxal scavenger are effective in reducing methylglyoxal- and diabetes-induced hyperalgesia. This previously undescribed concept of metabolically driven hyperalgesia provides a new basis for the design of therapeutic interventions for painful diabetic neuropathy. 相似文献