Pullulans produced by strains of Cryphonectria parasitica—II. Nuclear magnetic resonance evidence

The structure of pullullan-like polysaccharides produced as exocellular material by different strains of Cryphonectria parasitica, the fungus responsible for chestnut tree cankers, was investigated with nuclear magnetic resonance (NMR) techniques. ¹³C, mono- and bidimensional ¹H, and ¹H–¹³C heteronuclear correlated NMR spectra (HSQC and HMBC) were recorded. Advanced analysis of the NMR spectra allowed the main resonance of the atoms in the maltotriose and in the maltotetraose repeat units of pullulan-like polysaccharides from C. parasitica to be recognised with confidence. In all cases investigated, the presence of large amounts of -(1→6) maltotetraose subunits was evidenced, in addition to the -(1→6) maltotriose subunits, corresponding to the repeating unit of pullulan produced by Aureobasidium pullulans and other fungi. The results were in agreement with other data from this laboratory, obtained with independent techniques. The belief that in ‘pullulans’ the maximum amount of -(1→6) maltotetraose subunits is about 7% can thus be considered as definitely outdated.     

Internal fixation of malar fractures: an experimental biophysical study

Open reduction and internal fixation of displaced zygoma fractures are necessary to avoid immediate and delayed facial disfigurement. Interosseous wires, Kirschner wires, and more recently, rigid metallic miniplates have been recommended for fixation of these and other midfacial fractures. However, the precise physical stability of the zygoma with respect to wire versus miniplate fixation methods and with respect to the number and location of miniplates applied is not known. Noncomminuted zygoma fractures were simulated by saw osteotomy in eight fresh human cadaver heads (16 zygoma "fractures"). Each zygoma was sequentially fixated with three miniplates, two miniplates, one miniplate, and three interosseous wires across the orbital rim and arch "fractures". Static and oscillating loads simulating maximal physiologic masticatory stresses were applied to the fixated zygoma along the lines of action of the masseter muscle by means of a tensometer. The stability and adequacy of each pattern of fixation were recorded. Double-miniplate fixation across the orbital rim of simulated noncomminuted zygoma "fractures" is sufficient to withstand static and oscillating loading similar to physiologic masticatory forces. Neither single-miniplate fixation nor triple-wire fixation are sufficient to stabilize the zygoma against similar forces.     

Restoration of cut‐over bogs by floating raft formation: An experimental feasibility study

Abstract. Stimulation of floating peat by the introduction of poorly humified peat from four cut‐over bogs in The Netherlands was studied in a one‐year outdoor experiment. The pH of the various peat substrates was increased by adding different amounts of lime: 0–2 to 4–8 g‐CaCO₃.kg^‐1 fresh peat. Both peat type and lime addition were found to affect the buoyancy of the peat substrates. Low nutrient concentrations in the peat, together with a high bulk density, proved to be unfavourable for creating floating peat. Three of the peat types proved to be too acidic (pH < 4.5) to produce sufficient methane (ca. 400–600 μmol.L^‐1), and buoyancy was only achieved if lime was mixed in with the peat. The smallest amount of lime added (2 g.kg^‐1 fresh peat) was sufficient to maintain buoyancy for at least one year. Lime addition did not stimulate nutrient mobilization by mineralization, although P, N and K concentrations in the peat water were relatively high. It is concluded that floating peat can be initiated by the introduction of poorly humified peat. If the peat substrates are too acidic, lime can be added to stimulate buoyancy of the peat. Results are discussed in relation to restoration prospects.     

Femoral combs—a secondary sexual character in British Oscinellinae (Diptera: Chloropidae)

A specialised but variable group of setae on the middle femur of males of Chloropidae is described and its taxonomic importance discussed. This femoral comb has been found in 15 out of 24 genera of Oscinellinae, but was not found in 15 genera of Chloropinae.     

Purified lignin: Nutritional and health impacts on farm animals—A review

Lignin, the second most abundant natural compound after cellulose (Boudet and Grima-Pettenati, 1996), is a high-molecular weight polymer of phenolic compounds that occurs naturally in plants. It is mostly present in the cell wall, conferring structural support, impermeability and resistance to microbial attack. Commercial purified lignin is produced as a by-product of the paper industry, separated from wood by chemical pulping processes. These purified lignins are low molecular weight mono-phenolic fragments that have biological characteristics that differ from those of native lignin. Different chemical treatments during wood-pulping processes yield diverse types of purified lignin, such as Alcell lignin and Kraft lignin. Although these phenolic fragments may potentially have important applications in animal agriculture, research with purified lignin has not received much attention and there are few published results. In contrast to native lignin, purified lignin does not represent a barrier to digestion in monogastric or ruminant animals. Several in vitro and in vivo studies have demonstrated antimicrobial properties of the phenolic fragments in purified lignin. Recently, purified Alcell lignin has been shown to exhibit prebiotic effects in chickens, favouring growth of beneficial bacteria and improving the morphological structures of the intestines, as measured by increased villi height and goblet cell number. These findings suggest that purified lignin may exert health benefits in monogastric animals and could potentially be considered as a natural feed additive. Based on the few published studies, animal responses to purified lignin seem dependent on dosage, animal species and type and source of the lignin product. More research is required before establishing conclusive benefits of purified lignin on animal performance and health.     

Linear and nonlinear analyses of femoral fractures: Computational/experimental study

This paper describes two new methods for computational fracture analysis of human femur using Quantitative Computed Tomography (QCT) voxel-based finite element (FE) simulation. The paper also reports comprehensive mechanical testing for validation of the methods and evaluation of the required material properties. The analyses and tests were carried out on 15 human femurs under 11 different stance-type loading orientations. Several classical forms of subcapital, transcervical, basicervical, and intertrochanteric fractures plus a specific type of subtrochanteric fracture were created and analyzed. A new procedure was developed for prediction of the strengths and the fracture initiation patterns using a FE-based linear scheme. The predicted and observed fracture patterns were in correspondence, and the FE predictions of the fracture loads were in very good agreement with the experimental results. Moreover, the crack initiation and growth behaviors of two subtrochanteric fractures were successfully simulated through a novel implementation of the cohesive zone model (CZM) within a nonlinear FE analysis scheme. The CZM parameters were obtained through a series of experimental tests on different types of specimens and determination of a variety of material properties for different anatomic regions and orientations. The presented results indicated that the locations and patterns of crack initiation, the sequences of crack growth on different paths, and the compatibility of growth increments agreed very well with the observed specifications. Also, very good agreements were achieved between the measured and simulated fracture loads.     

降雨和汇流对黑土区坡面土壤侵蚀的影响试验研究

东北黑土区上坡汇流对坡面土壤侵蚀有重要影响,因此辨析降雨和汇流对黑土区坡面土壤侵蚀的影响对农田土壤侵蚀防治有重要意义。通过设计不同降雨强度和汇流速率以及二者组合的模拟降雨及上方汇流试验,分析了降雨和汇流对黑土坡面侵蚀的影响及其贡献。试验处理包括两个降雨强度(50 mm/h和100 mm/h)、两个汇流速率(50 mm/h和100 mm/h,即:10 L/min和20 L/min)、以及4种不同降雨强度和汇流速率的组合((50+50)mm/h、(50+100)mm/h、(100+50)mm/h和(100+100)mm/h)。结果表明,在50 mm/h和100 mm/h上方汇流引起的坡面侵蚀量仅分别是50 mm/h和100 mm/h降雨引起坡面侵蚀量的1.9%和0.6%;当降雨强度和坡上方汇流速率分别由50 mm/h增加至100 mm/h时,降雨试验处理下的坡面侵蚀量增加6.1倍,汇流试验处理下的坡面侵蚀量增加3.2倍,说明降雨对坡面土壤侵蚀的影响显著大于汇流的作用。在降雨和汇流组合试验中,总供水强度(降雨强度+汇流速率)为150 mm/h时,降雨强度为100 mm/h和汇流速率为50 mm/h组合试验的坡面侵蚀量是降雨强度为50 mm/h和汇流速率为100 mm/h组合试验坡面侵蚀量的7.9倍。在相同汇流条件下,降雨强度由50 mm/h增加到100 mm/h时,降雨强度的增加对坡面侵蚀量的贡献率为89.6%-99.5%;而在相同降雨条件下,坡面汇流速率由50 mm/h增加100 mm/h时,汇流速率的增加对坡面侵蚀量的贡献率为17.2%-78.7%,说明在东北黑土区防治坡面汇流对坡面土壤侵蚀影响也尤为重要。     

Examination of antimicrobial effect of fluoxetine in experimental sepsis model: An in vivo study

Since most infectious diseases can develop into sepsis, it is still a major medical problem. Some in-vivo studies showed promising properties of fluoxetine in the treatment of infections. This study aims the antimicrobial effect of fluoxetine on the inflammatory process used in the treatment of sepsis-modeled rats. Besides, to investigate the efficacy of fluoxetine on modifying the antibiotic effect of imipenem in the inflammatory response. An experimental sepsis model was divided into negative control, positive control, fluoxetine 5 mg/kg, imipenem 60 mg/kg, and combined (fluoxetine; imipenem). Procalcitonin (PCT), high-sensitivity C-reactive protein (hs-CRP), lactate, myeloperoxidase activity (MPO), the inflammation markers interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-alfa (TNF-α), and monocyte chemoattractant protein-1 (MCP-1) levels were measured by enzyme-linked immunosorbent assay method. Oxidative stress markers, total oxidant status (TOS), total antioxidant status (TAS), total thiol (TT), and native thiol (NT) were measured using photometric methods. Oxidative stress index (OSI) was calculated according to TAS and TOS levels. The statistical analysis was performed by Statistical Package for Social Sciences version 22.0. After treatment with fluoxetine, imipenem, and combined groups, IL-1β, IL-6, TNF-α, MPO activity, MCP-1, hs-CRP, PCT, lactate, and the oxidative stress markers OSI, and disulfide levels were decreased (p < 0.05). The TT, NT, and TAS levels significantly statistically increased (p < 0.05). This research demonstrates that fluoxetine has effects as anti-inflammatory and antioxidant, and the combined treatment with antibioticum imipenem indicates positive synergistic effects in the experimental sepsis model.