Static and Dynamic Stiffness of Reinforced Concrete Beams Strengthened with Externally Bonded CFRP Strips

This paper presents experimental investigations of reinforced concrete (RC) beams flexurally strengthened with carbon fiber reinforced polymer (CFRP) strips. Seven 3300 mm × 250 mm × 150 mm beams of the same design, with the tension reinforcement ratio of 1.01%, were tested. The beams differed in the way they were strengthened: one of the beams was the reference, two beams were passively strengthened as precracked (series B-I), two beams were passively strengthened as unprecracked (series B-II) and two beams were actively strengthened as unprecracked (series B-III). Moreover, the strengthening parameters differed between the particular series. The parameters were: CFRP strip cross-sectional areas (series B-I, B-II) or prestressing forces (series B-III). The beams were statically loaded, up to the assumed force value, in the three-point bending test and deflections at midspan were registered. After unloading the beams were suspended on flexible ropes (the free-free beam system) and their eigenfrequencies were measured using operational modal analysis (OMA). The static measurements (deflections) and the dynamic measurements (eigenfrequencies) were conducted for the adopted loading steps until failure. Static stiffnesses and dynamic stiffnesses were calculated on the basis of respectively the deflections and the eigenfrequencies. The qualitative and quantitative differences between the parameters are described.     

How lonely they are? A degree of isolation among macrozoobenthos species in the Marine Protected Area, the Bay of Puck, the Southern Baltic

Extensive sampling (450 grabs) was performed all over the inner part of Puck Bay (105 km² area) in summers of 2007–2009. The GIS-based analysis of samples was performed to assess in detail the distribution of 32 benthic species. The minimum area of occurrence was less than 1 km² for Lekanosphaera rugicauda and the maximum was 83 km² for Cerastoderma glaucum. The material reveals that species with the pelagic larval stage were most widespread, with the least distance between individuals and the highest average density (e.g. Cerastoderma glaucum, Hydrobia ventrosa). The most isolated and the least dense species within the studied area were discretely mobile, non-larval crustaceans (e.g. Gammarus oceanicus and Lekanosphaera rugicauda), present at single sites with the largest distance from each other. We conclude that analysis of species distribution helps in understanding the threats to populations of marine invertebrates and marine spatial planning, through locating the isolated species and populations.     

Advances in the diagnosis and management of diabetic distal symmetric polyneuropathy

Distal symmetric polyneuropathy (DSPN) is the most common chronic complication of diabetes mellitus. The pathogenesis of DSPN is not fully elucidated, but it is certainly multifactorial in nature and attributable to metabolic and microvessel disorders related to chronic hyperglycemia, diabetes duration, and several cardiovascular risk factors. Early diagnosis and appropriate management are extremely important, since up to 50% of DSPN cases may be asymptomatic, and patients are unaware of foot injury leading to foot ulcers and amputation. Simple, validated tests such as the Neuropathy Disability Score and/or Vibration Perception Threshold may be used to diagnose DSPN. Similarly, neurological dysfunction screening questionnaires should be used to assess the quality and severity of DSPN symptoms. Using both methods enables prediction of the prognosis of diabetic patients with DSPN. No causative treatment of DSPN is known, but the results of clinical trials indicate that several treatment options are highly effective in symptomatic treatment of painful DSPN. The appropriate treatment of DSPN may improve the outcome, preventing or delaying the development of numerous diabetic complications.     

Effect of sodium dichloroacetate on apoptotic gene expression in human leukemia cell lines

Background

Sodium dichloroacetate (DCA) is an agent with anticancer properties against solid tumors. DCA also seems to have antileukemic activity. In order to affirm it we investigate the effect of DCA on cell viability and apoptotic gene expression profiles in leukemia cell lines: CEM/C1, CCRF/CEM, HL-60, HL-60/MX2.

Inter-observer and intra-observer reliability in the radiographic measurements of paediatric forefoot alignment

BackgroundFoot bones in children have more rounded shapes in radiograms than adults. Thus, the goal of this work was assessing inter- and intra-observer reliability in paediatric forefoot angle measurements.Material and methodsSix forefoot angles in 34 AP standing paediatric foot radiographs were measured by 5 researchers. A classic statistical analysis with use of IBM SPSS Statistics 25 was performed and a new method with two-way analysis of variance was applied.ResultsResults of statistical analysis revealed the properties of a subjective assessment related to specific angles. Kilmartin’s angle, calcaneus-fifth metatarsal angle and first ray angle are the most reliable; metatarsus adductus angle should be used with great caution in pediatric population. Engel’s angle is the most difficult for measuring and measurement error is the highest.ConclusionThe power of paediatric forefoot measurements is various. Several angles are reliable, while Engle’s angle is the most doubtful.