Individual Plates Research Articles

A microbiological multi-plate method to detect cephalosporin residues in milk

The aim of this study was to determine the detection capability (CCβ) of a multi-plate diffusion method for selected cephalosporins for which the maximum residue limits (MRLs) in milk have been set (ceftiofur, cefoperazone, cephalexine, cephazoline, cephalonium, cephapirine, cefquinome). The multiplate method was composed of Bacillus subtilis BGA CCM 4062 plates (agar pH of 6, 8 and 7.2); Kocuria rhizophila CCM 552 plate, Geobacillus stearothermophilus CCM 5965 plate and Escherichia coli CCM 7372 plate. Geobacillus stearothermophilus plate showed the highest sensitivity. CCβ for the tested cephalosporins was determined at MRLs or lower, except for cefquinome, which was undetectable even at 12 × the MRL. Kocuria rhizophila plate showed the highest sensitivity to ceftiofur (CCβ = 100 μg/l); cephazoline and cephalonium could not be detected even at 12 × times the MRL. Escherichia coli plate was most sensitive to cefoperazone (CCβ = 60 μg/l). Other than cephapirine, none of the cephalosporins could be detected by B. subtilis BGA (pH 6, 8 and 7.2) plates even at 12 × the MRL. Our results demonstrate the differences in sensitivity to selected cephalosporins of the individual plate methods that together form the multi-plate method. The multi-plate method is sensitive enough to detect most of the tested cephalosporins, with the exception of cefquinome, which could not be detected at levels close to MRL.

Establishing a Fed-Batch Process for Protease Expression with Bacillus licheniformis in Polymer-Based Controlled-Release Microtiter Plates.

Introducing fed-batch mode in early stages of development projects is crucial for establishing comparable conditions to industrial fed-batch fermentation processes. Therefore, cost efficient and easy to use small-scale fed-batch systems that can be integrated into existing laboratory equipment and workflows are required. Recently, a novel polymer-based controlled-release fed-batch microtiter plate is described. In this work, the polymer-based controlled-release fed-batch microtiter plate is used to investigate fed-batch cultivations of a protease producing Bacillus licheniformis culture. Therefore, the oxygen transfer rate (OTR) is online-monitored within each well of the polymer-based controlled-release fed-batch microtiter plate using a µRAMOS device. Cultivations in five individual polymer-based controlled-release fed-batch microtiter plates of two production lots show good reproducibility with a mean coefficient of variation of 9.2%. Decreasing initial biomass concentrations prolongs batch phase while simultaneously postponing the fed-batch phase. The initial liquid filling volume affects the volumetric release rate, which is directly translated in different OTR levels of the fed-batch phase. An increasing initial osmotic pressure within the mineral medium decreases both glucose release and protease yield. With the volumetric glucose release rate as scale-up criterion, microtiter plate- and shake flask-based fed-batch cultivations are highly comparable. On basis of the small-scale fed-batch cultivations, a mechanistic model is established and validated. Model-based simulations coincide well with the experimentally acquired data.

Mir-374-5p, mir-379-5p, and mir-503-5p Regulate Proliferation and Hypertrophic Differentiation of Growth Plate Chondrocytes in Male Rats

Growth plate chondrocytes undergo sequential differentiation to form the resting zone, the proliferative zone (PZ), and the hypertrophic zone (HZ). The important role of microRNAs (miRNAs) in the growth plate was previously revealed by cartilage-specific ablation of Dicer, an enzyme essential for biogenesis of many miRNAs. To identify specific miRNAs that regulate differentiation of PZ chondrocytes to HZ chondrocytes, we microdissected individual growth plate zones from juvenile rats and performed miRNA profiling using a solution hybridization method and miRNA sequencing. Thirty-four miRNAs were differentially expressed between the PZ and the HZ, and we hypothesized that some of the miRNAs that are preferentially expressed in the PZ may promote proliferation and inhibit hypertrophic differentiation. Consistent with this hypothesis, transfection of inhibitors for four of these miRNAs (mir-369-3p, mir-374-5p, mir-379-5p, and mir-503-5p) decreased proliferation in primary epiphyseal chondrocytes. The inhibitors for three of these miRNAs (mir-374-5p, mir-379-5p, and mir-503-5p) also increased expression of multiple genes that are associated with chondrocyte hypertrophic differentiation. We next hypothesized that preferential expression of these miRNAs in the PZ is driven by the parathyroid hormone-related protein (PTHrP) concentration gradient across the growth plate. Consistent with this hypothesis, treatment of primary chondrocytes with a parathyroid hormone (PTH)/PTHrP receptor agonist, PTH1-34, increased expression of mir-374-5p, mir-379-5p, and mir-503-5p. Taken together, our findings suggest that the PTHrP concentration gradient across the growth plate induces differential expression of mir-374-5p, mir-379-5p, and mir-503-5p between the PZ and the HZ. In the PZ, the higher expression levels of these miRNAs promote proliferation and inhibit hypertrophic differentiation. In the HZ, downregulation of these miRNAs inhibits proliferation and promotes hypertrophic differentiation.

Mechanistic Studies on Cationization in MALDI-MS Employing a Split Sample Plate Set-up.

In the analysis of polymers by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS), a commonly observed ionization pathway is cation-adduct formation, as polymers often lack easily ionizable (basic/acidic) functional groups. The mechanism of this process has been hypothesized to involve gas-phase cation attachment. In previous experiments, a split sample plate set-up has been introduced, enabling separate deposition of the components on individual MALDI plates. The plates are divided by a small gap of a few micrometers, allowing simultaneous laser irradiation from both plates, while precluding the possibility of any other interactions prior to ablation. Here, we extend on these studies by using different polymer-salt combinations to test the generalizability of a gas-phase ionization process. Clear evidence for in-plume ionization is presented for the model polymers poly (methyl methacrylate) and polystyrene. Furthermore, the contribution of in-plume processes to the overall ion formation by cationization is gauged, providing a first estimate for the importance of this pathway.

Archaeometric characterisation and origin of black coatings on prehistoric pottery

Black or dark grey vessel surfaces with characteristic metallic lustre are recognised from various archaeological contexts throughout Europe. This feature is commonly attributed to the application of graphite-bearing coatings onto ceramic vessels. However, recent experimental studies have shown that a very similar visual effect can alternatively be achieved by polishing and, subsequently, firing in a reducing atmosphere (so-called smudging). In this study, experimentally manufactured ceramics as well as samples of prehistoric ware (dated to the Neolithic Age, late Bronze Age and early Iron Age) have been analysed to find the distinguishing features between graphite-based and non-mineral black coatings. In the low-magnification BSE images the well-preserved graphite-coated surfaces are characterized by a distinctive spotty pattern with numerous dark grey angular fragments of monomineralic or nearly monomineralic metamorphic rocks scattered in the clay groundmass. Provided that polished thin sections are skilfully prepared, individual graphite plates can be easily recognized in the near-surface layer of the sherds using polarized reflected light microscopy. A relatively homogeneous appearance is typical of the low-magnification BSE images of surfaces coated by smudging. At higher magnifications, presence of blurred darkish stains (presumably organic-derived, as indicated by elevated levels of biogenic elements) is characteristic of this kind of non-mineral black coatings. SEM-EDS and optical microscopy have been supplemented by micro-Raman spectroscopy, which allows differentiation between various carbonaceous phases.

Aerodynamic interaction of collective plates in side-by-side arrangement

In the tip-reversal upstroke of avian flight, individual feathers twist so as to create gaps between them. Although this behavior allows the feathers to function as individual lift-generating bodies, the lift generation mechanism of these multiple bodies remains unclear. This paper reports a numerical investigation of multiple stationary plates arranged side by side in a uniform flow. The aim is to elucidate the collective mechanism of the flow generated by the plates and the lift contribution of each plate. The angle of attack of each plate and the gap between the plates are varied to determine their influence on the flow and lift of the collection of plates. The time-averaged lift increases from the lowermost to the uppermost plate, and, at a high angle of attack, the total lift coefficient of the plates becomes greater than that of a single plate solely placed in a uniform flow. At a high angle of attack, vortex shedding from the upper plates is synchronized with some phase difference, resulting in synchronized lift fluctuations for individual plates and a reduction in the overall fluctuation amplitude. With an optimal gap ratio and angle of attack, the collective behavior of plates in side-by-side arrangement can be advantageous to enhance lift-generation performance.

The illustrations to Dugdale’s History of St Paul’s Cathedral: subscribers and their sentiments

ABSTRACT This article considers William Dugdale’s History of St Paul’s Cathedral (1658) as an elegy for a great national church that had been neglected and vandalised during the Commonwealth years. Its dilapidated condition is an eloquent commentary on the plight of the suppressed episcopal Church. Dugdale’s intention of showing the cathedral in an idealised state as it might have been before the Civil War required many illustrations which had to be paid for by supporters of the Anglican mode of worship, and the article pays particular attention to the sponsors of the individual plates, and to the sentiments (in Latin) which the subscribers could place on the engravings they had paid for. The cumulative effect of these sentiments is an overwhelming sense of the decay of piety in Commonwealth England.

Pilot Evaluation of Aggregate Plate Waste as a Measure of Students’ School Lunch Consumption (OR13-08-19)

ObjectivesWeighing individual plate waste provides reliable estimates of food intake by physically weighing individual food components to the nearest gram before and after a meal. Weighing aggregate, school-level food waste may be an inexpensive and less time-consuming alternative. However, it has not been determined whether aggregate plate waste is an accurate measure of individual plate waste. This pilot study therefore aimed to evaluate the accuracy of aggregate plate waste for quantifying food waste in a school cafeteria setting in comparison to individual weighed plate waste. MethodsThis study took place in an urban, low-income school district in Massachusetts. Four elementary schools that shared two identical cafeterias and served the same foods each day participated in the study. Participating students in the four schools had similar demographic characteristics. Cafeterias were randomly assigned to either individual or aggregate plate waste measurements. Plate waste was collected for 4 days from approximately n = 850 students in each cafeteria on the same days. For individual plate waste, the % consumed was calculated for each food item on each student’s tray. In the cafeteria with aggregate-level measurements, waste was separated by component (entrée, vegetable, fruit, and milk), and weighed to calculate the % consumed. Intraclass correlation coefficients (ICCs) were calculated to assess the agreement between aggregate plate waste and individual-level plate waste. ResultsAgreement was excellent for entrées (ICC = 0.90) and vegetables (ICC = 0.78), but poor for milk (ICC = 0.22) and fruits (ICC = 0.23). The overall agreement for all four components combined was excellent (ICC = 0.75). ConclusionsResults suggest that aggregate plate waste may be a reasonable measure of individually weighed plate waste, but additional research is warranted. Funding SourcesA grant from Arbella Insurance funded the data collection. The current analysis had no funding or support. Supporting Tables, Images and/or Graphs▪▪

Pilot Evaluation of Aggregate Plate Waste as a Measure of Students’ School Lunch Consumption

Weighing an individual's plate waste provides reliable estimates of food intake by physically weighing individual food components to the nearest gram before and after a meal. Weighing aggregate, school-level food waste may be an inexpensive and less time-consuming alternative. However, it has not been determined whether aggregate plate waste is an accurate measure of individually weighed plate waste. This pilot study aimed to evaluate the accuracy of aggregate plate waste for quantifying food waste in a school cafeteria setting in comparison with individually weighed plate waste. A pilot validation study in which aggregate plate waste was compared against individually weighed plate waste in a school cafeteria setting. This study took place in an urban, low-income school district in Massachusetts in the spring of 2014. Four elementary schools with identical cafeterias and meals participated in the study. Approximately 1,700 students participated in this study. For individually weighed plate waste, the percent discarded was calculated by dividing the weight of each discarded item by the average weight of the food item served and the percent consumed was calculated as the residual. For aggregate-level measurements, waste was separated by component (entrée, vegetable, fruit, and milk), and the weight discarded was calculated based on the weight of the cumulative amount remaining and an average weight for each food item served, with the percent consumed calculated as the residual. Intraclass correlation coefficients (ICCs) were calculated to assess the agreement between aggregate plate waste and individual-level plate waste values. Agreement was excellent for entrées (ICC=0.90) and vegetables (ICC=0.78), but poor for milk (ICC=0.22) and fruits (ICC=0.23). The overall agreement for all four components combined was excellent (ICC=0.75). Results suggest that aggregate plate waste may provide a reasonable estimate of individually weighed plate waste, but additional research is warranted.

A force-measuring and behaviour-recording system consisting of 24 individual 3D force plates for the study of single limb forces in climbing animals on a quasi-cylindrical tower

This study describes the design of a new force measuring array with a quasi-cylindrical surface for measuring the 3D ground reaction forces of animals climbing on a surface with high curvature. This force-measuring array was assembled from 24 individual 3D force sensors, each with a resolution at the millinewton (mN) level, which were installed from top to bottom in four columns and six rows, with sensors in neighbouring columns staggered in height. Three cameras were used to simultaneously record the climbing behaviours of animals (in these experiments tree frogs) on the cylinder-like force measuring array. We were thus able to simultaneously record the ground reaction forces of each of the four limbs of tree frogs (here six individuals of the Chinese gliding or flying frog, Rhacophorus dennysi, with forelimb spans in the range 163–201 mm) climbing or descending both smooth and rough surfaces on a quasi-cylindrical structure with an overall diameter of 79 mm. We describe the design and calibration of the individual force sensors, their installation and arrangement on the quasi-cylindrical climbing tower, the recording of ground reaction forces and climbing behaviour, data transformations necessitated by the angular relationship of neighbouring sensors, and data processing using MATLAB scripts. Additionally, we present preliminary data on the use of a clamping grip by climbing frogs and the existence of small pull-off forces that aid toe-pad detachment at the end of each locomotor stance phase.

The usage of an individual plate for osteosynthesis at hip joint arthroplasty in a patient with a long-term transacetabular fracture with bone fragments displacement

The usage of an individual plate for osteosynthesis at hip joint arthroplasty in a patient with a long-term transacetabular fracture with bone fragments displacement

Experimental Analysis of a Novel Cooling Material for Large Format Automotive Lithium-Ion Cells

Cooling the surface of large format batteries with solid conductive plates, or fins, has an inherent advantage of reducing the number of liquid seals relative to some mini-channel cold plate designs, as liquid is not passed through the numerous individual plates directly. This may reduce the overall pack leakage risk which is of utmost importance due to safety concerns associated with the possibility of a cell short circuit and thermal runaway event. However, fin cooling comes at a cost of an increased thermal resistance which can lead to higher cell temperatures and a poorer temperature uniformity under aggressive heat generation conditions. In this paper, a novel graphite-based fin material with an in-plane thermal conductivity 5 times greater than aluminium with the same weight is presented for advanced battery cooling. The thermal performance of the fin is benchmarked against conventional copper and aluminium fins in an experimental programme cycling real 53 Ah pouch cells. The results from the extensive experimental testing indicate that the new fin can reduce both the peak measured temperature and surface temperature gradient by up to 8 °C and 5 °C respectively, when compared to aluminium fins under an aggressive electric vehicle duty-cycle.

Growth and mineralogy in dental plates of the holocephalan Harriotta raleighana (Chondrichthyes): novel dentine and conserved patterning combine to create a unique chondrichthyan dentition

The dentition in extant holocephalans (Chondrichthyes) comprises three pairs of continuously growing dental plates, rather than the separate teeth characterizing elasmobranchs. We investigated how different types of dentine in these plates, including hypermineralized dentine, are arranged, and how this is renewed aborally, in adult and juvenile dentitions of Harriotta raleighana (Rhinochimeridae). Individual plates were analysed using x-ray computed tomography (μCT), scanning electron microscopy (SEM) in back scattered mode with energy dispersive X-ray (EDX) analysis, and optical microscopy on hard tissue sections.ResultsHarriotta dental plates are made entirely of dentine tissue, mostly as trabecular dentine, bone itself being absent. Hypermineralized dentine forms in restricted ovoid and tritor spaces within trabecular dentine, inside a shell of outer and inner dentine layers. Trabecular dentine is ubiquitous but changes to sclerotic osteodentine near the oral surface by increasing density, remaining less mineralized than the hypermineralized dentine. All structures are renewed aborally, within a vascular dental pulp, a tissue suggested to be a source of stem cells for tissue renewal. Ca density profiles and concentrations of Mg, P, and Ca ions reveal extreme differences in the level and type of mineralization. Early mineralization in ovoids and tritors has very high levels of Mg, then a sudden increase in mineralization to a high total mineral content, whereas there is gradual change in trabecular dentine, remaining at a low level.Hypermineralized dentine fills the prepatterned ovoid, rod and tritor spaces, early at the aboral surface within the trabecular dentine. Deposition of the hypermineralized dentine (HD, proposed as new specific name, whitlockin replacing pleromin) is from surfaces that are lined with large specialized odontoblasts, (whitloblasts, instead of pleromoblasts) within cell body spaces connecting with extensive, ramifying tubules. Early mineralization occurs amongst this maze of tubules that penetrate far into the dentine, expanding into a mass of saccules and membranous bodies, dominating in the absence of other organic matrix. This early stage has hydroxyapatite, also significantly rich in Mg, initiated as a poorly crystalline phase. In the hypermineralized dentine, formation occurs as clusters of variably shaped crystals, arising from a sudden phase transition.ConclusionsIn the hypermineralized dentine, high MgO + CaO + P2O5 suggests that almost pure Mg containing tricalciumphosphate (MgTCP: (ß-Ca3(PO4)2) (whitlockite) is present, with little or no hydroxyapatite. Serial replacement of tritors and ovoids is suggested to occur within the dental plate, probably representing a relic of patterning, as classically found in elasmobranch dentitions.

Origin and Quantification of Increased Core Loss in MnZn Ferrite Plates of a Multi-Gap Inductor

Inductors realized with high permeable MnZn ferrite require, unlike iron-powder cores with an inherent dis-tributed gap, a discrete air gap in the magnetic circuit to prevent saturation of the core material and/or tune the inductance value. This large discrete gap can be divided into several partial gaps in order to reduce the air gap stray field and consequently the proximity losses in the winding. The multi-gap core, realized by stacking several thin ferrite plates and inserting a non-magnetic spacer material between the plates, however, exhibits a substan-tial increase in core losses which cannot be explained from the intrinsic properties of the ferrite. In this paper, a comprehensive overview of the scientific literature regarding machining induced core losses in ferrite, dating back to the early 1970s, is provided which suggests that the observed excess core losses could be attributed to a deterioration of ferrite properties in the surface layer of the plates caused by mechanical stress exerted during machining. However, in a first experimental analysis no structural evidence for a deteriorated layer close to the surface is identified by means of Scanning Electron Microscopy (SEM). Therefore, in a next step, a new calorimetric measurement setup based on temperature rise monitoring is proposed in this paper in order to quantify and differentiate between core losses associated with the bulk and the surface of the ferrite plates and therefore to pinpoint the measured excess core loss to shallow layers of ferrite with deteriorated magnetic performance. Electrical measurement of the surface related core losses utilizing the widely accepted two-winding wattmeter method with reactive power compensation is outlined in the appendix but was not employed in this work due to comparably low measurement accuracy. By means of the proposed measurement technique, the bulk and surface core loss density of the MnZn ferrite material 3F4 from FerroxCube was determined for sinusoidal flux density amplitude varying from 75 mT up to 200 mT and excitation frequencies ranging from 200 kHz to 1 MHz. The measured core loss densities (W/cm 3 ) show good agreement with the Steinmetz model provided by the manufacturer validating the proposed calorimetric core loss measurement technique. The measured surface loss density (W/cm 2 ) can also be well predicted with a Steinmetz model, whereby the frequency exponent α in the surface is slightly smaller and the flux density exponent β is slightly larger compared to the Steinmetz parameter of the bulk ferrite. It is shown that the ratio between surface and bulk core losses of a composite core assembled from individual plates is only a function of plate thickness and does not depend on the actual cross section area. Critical plate thickness is then defined to be reached when the total power loss in the composite core has doubled compared to a solid (single-piece) core sample. This new quantity provides a very helpful figure for multi-gap inductor designs. Besides the deteriorated surface layers, several other mechanisms potentially contributing to increased core losses in multi-gap inductors were identified and are finally discussed in the appendix of this paper: flux crowding in the core due to tolerances and imperfections in machining and assembly; deterioration of ferrite properties due to pressure buildup in the stack of plates during the curing of the employed epoxy resin; ohmic loss in the ferrite associated with the current flowing in the conduction path provided by the low impedance of the ferrite material at high frequencies and the parasitic capacitance between winding and the ferrite core.

Formulae for Calculating Elastic Local Buckling Stresses of Full Structural Cross-sections

Formulae for determining the full cross-section elastic local buckling stress of structural steel profiles under a comprehensive range of loading conditions, accounting for the interaction between the individual plate elements, are presented. Element interaction, characterised by the development of rotational restraint along the longitudinal edges of adjoined plates, is shown to occur in cross-sections comprising individual plates with different local buckling stresses, but also in cross-sections where the isolated plates have the same local buckling stress but different local buckling half-wavelengths. The developed expressions account for element interaction through an interaction coefficient ζ that ranges between 0 and 1 and are bound by the theoretical limits of the local buckling stress of the isolated critical plates with simply-supported and fixed boundary conditions along the adjoined edges. A range of standard European and American hot-rolled structural steel profiles, including I-sections, square and rectangular hollow sections, channel sections, tee sections and angle sections, as well as additional welded profiles, are considered. The analytical formulae are calibrated against results derived numerically using the finite strip method. For the range of analysed sections, the elastic local buckling stress is typically predicted to within 5% of the numerical value, whereas when element interaction is ignored and the plates are considered in isolation with simply-supported boundary conditions along the adjoined edges, as is customary in current structural design specifications, the local buckling stress of common structural profiles may be under-estimated by as much as 50%. The derived formulae may be adopted as a convenient alternative to numerical methods in advanced structural design calculations (e.g. using the direct strength method or continuous strength method) and although the focus of the study is on structural steel sections, the functions are also applicable to cross-sections of other isotropic materials.

Functional Reconstruction of Mandibular Segment Defects With Individual Preformed Reconstruction Plate and Computed Tomographic Angiography-Aided Iliac Crest Flap

With the development of imaging technology and computer-assisted surgery in oral and maxillofacial surgery, digital technology is widely used in vascularized bone flap grafts for mandibular reconstruction. The aim of this study was to use digital technology throughout the treatment process to show that digital techniques can provide a reliable and accurate match between the mandible and the iliac crest flap to achieve functional reconstruction of mandibular segment defects. Twenty patients underwent 3-dimensional (3D) computed tomography (CT), mirroring technology, 3D model prototyping, and CT angiography (CTA) for treatment planning. Individual preformed reconstruction plates were fabricated and iliac crest flaps were designed preoperatively. After complete resection of the mandibular lesion, the iliac crest flap was shaped to reconstruct the mandibular defects. During follow-up (range, 12 to 36months), the facial shape, facial symmetry, and mouth opening of all patients recovered well. The 3D CT reconstruction also was evaluated for height, width, length, and bone healing of the iliac crest flap. Postoperative examination showed ideal bone union between the iliac crest flap and the mandible at 6months. Nine patients received implant-supported fixed dentures to restore dentition. After follow-up, all patients were satisfied with their facial esthetics and function. The new mandible provided a suitable3D position for implant-supported fixed partial dentures. Use of digital techniques throughout the course of treatment improves the predictability and convenience of functional mandibular reconstruction. Individual preformed reconstruction plates and CTA effectively guaranteed the accuracy of iliac flap preparation.

Corrosion and Anodizing Behavior of T1 (Al2CuLi) Precipitates in Al-Cu-Li Alloy

T1 (Al2CuLi) phase precipitates, the main strengthening precipitates in third generation aluminum-copper-lithium (Al-Cu-Li) alloys, play a critical role in determining the corrosion behavior of these alloys. Herein, the T1 precipitates, sufficiently large to be visualized by scanning electron microscopy, were intentionally grown in a commercial Al-Cu-Li alloy through a high temperature annealing process. The corrosion and anodizing behavior of the alloy associated with individual T1 precipitate plates was subsequently investigated. It was observed that corrosion initiated instantaneously on T1 precipitate plates when the alloy was exposed to laboratory air. When immersed in NaCl solution, T1 precipitate plates corroded through a dealloying process and then, drove anodic dissolution of the adjacent aluminum alloy matrix by forming copper-rich nanoparticles at the sites of dealloyed T1 precipitates. The T1 phase precipitates were anodized relatively faster than the aluminum matrix in tartaric-sulfuric acid solution under a constant voltage of 14 V. The anodic film formed from T1 precipitates was dissolved quickly by the anodizing electrolyte during anodizing at relatively higher temperatures, resulting in cavities of sizes similar to those of T1 precipitate plates.

On course to smart large-diameter pipe production

Abstract In the production of longitudinally submerged-arc welded (LSAW) large-diameter steel pipes – covering diameters in the range of 18 to 56 inch – a complex sequence of manufacturing processes has to be planned and optimized to match strict market requirements. Thus, two approaches are essential. On the one hand process optimizations have to be done with regard to the process interrelations along the whole process chain. On the other hand process deviations based on material variations have to be managed with reference to each individual steel plate. In this context, a new concept for process chain control is presented comprising an up-to-date calculation model for offline and real-time optimization of the LSAW pipe production process chain – including measuring and feedback-control systems. Core processes are controlled in consideration of real-time information coming from upstream and downstream processes. Due to intelligent algorithms, interrelations between subsequent forming processes (e.g. plate edge crimping, pipe forming, pipe closing, tack welding, pipe expanding) are processed by a higher-level process chain model. As a practical example, the efficiency of the real-time feedback control algorithm is shown with focus on the pipe forming press. Influencing factors (e.g. variations in yield stress and wall thickness, positioning accuracy) are discussed on the basis of extensive simulations. Corresponding model algorithms are presented and compared with practical results. The presented concept aims at a reduced start-up time for producing new pipe dimensions and at tighter tolerances for finished pipe dimensions. Furthermore, it allows for traceable real-time optimization of current production in existing LSAW pipe mills.

Bottom-up effects on biomechanical properties of the skeletal plates of the sea urchin Paracentrotus lividus (Lamarck, 1816) in an acidified ocean scenario

Sea urchins, ecologically important herbivores of shallow subtidal temperate reefs, are considered particularly threatened in a future ocean acidification scenario, since their carbonate structures (skeleton and grazing apparatus) are made up of the very soluble high-magnesium calcite, particularly sensitive to a decrease in pH. The biomechanical properties of their skeletal structures are of great importance for their individual fitness, because the skeleton provides the means for locomotion, grazing and protection from predators. Sea urchin skeleton is composed of discrete calcite plates attached to each other at sutures by organic ligaments. The present study addressed the fate of the sea urchin Paracentrotus lividus (Lamarck, 1816) skeleton in acidified oceans, taking into account the combined effect of reduced pH and macroalgal diet, with potential cascading consequences at the ecosystem level. A breaking test on individual plates of juvenile specimens fed different macroalgal diets has been performed, teasing apart plate strength and stiffness from general robustness. Results showed no direct short-term effect of a decrease in seawater pH nor of the macroalgal diet on single plate mechanical properties. Nevertheless, results from apical plates, the ones presumably formed during the experimental period, provided an indication of a possible diet-mediated response, with sea urchins fed the more calcified macroalga sustaining higher forces before breakage than the one fed the non-calcified algae. This, on the long term, may produce bottom-up effects on sea urchins, leading to potential shifts in the ecosystem equilibrium under an ocean acidified scenario.

Dosimetry verification of radioactive seed implantation for recurrent malignant tumor of head and neck assisted by 3D printing individual guide plate

Objective To compare the dose distributions of postoperative plans with preoperative plans for 3D printing guide plate assist radioactive seeds implantations, explore the effects of the technology for seeds implantations in dosimetry level. Methods From January 2016 to December 2016, a total of 42 patients of local recurrent malignant tumor of head and neck received 3D printing guide plate assist radioactive seeds implantations in in Peking University Third Hospital, and included in the retrospective study. The prescribed dose was 110-160 Gy. All patients carried out preoperative planning design, individual guide plate production, and compared the dose distribution of postoperative plan with preoperative plan. Dose parameters include D90, mPD, V100, V150, V200, CI, EI and HI. Statistical method was paired t-test. Results A total of 42 3D printing individual templates were produced. The mean GTV volume of all patients was 28.6 cm3, and mean D90 of postoperative target area (GTV) was 142.6 Gy. For postoperative plans, the mean D90, mPD, V100, V150, V200 was 142.6 Gy, 77.3 Gy, 92.48%, 68.40% and 42.98%, respectively, and 144.5 Gy, 70.2 Gy, 91.45%, 63.12% and 34.74%, respectively, in preoperative plans. Except mPD, V150, V200(t=-2.166, -2.863, -4.778, P<0.05), there was no significant difference between the two groups. Conclusions 3D printing guide plate could provide good accuracy for positioning and direction. For local recurrent malignant tumor of head and neck, the actual dose distributions in postoperative validations were close to the expectations of preoperative plans which mean the improvement of accuracy in treatment. Key words: 3D printing; Radioactive seed implantation; Dosimetry; Malignant tumor; Head and neck; Cancer