The structure and mechanics of Moso bamboo material

Bamboo has been used structurally for thousands of years. Recently, structural bamboo products analogous to wood products have become of interest both commercially and academically. This file contains original experimental results of an investigation of both the microstructure and mechanical properties of natural Moso bamboo (Phyllostachys pubescens). One of the primary aims of the investigation is to contribute data and knowledge in order to facilitate the design of products and structures with bamboo. The authors of the dataset hope making the data available allows for easy comparison and combination with others’ results, thusly furthering this goal. The raw experimental data contained in this file is the dataset presented in the article “The Structure and Mechanics of Moso Bamboo Material” in Journal of the Royal Society Interface, with which the dataset shares a name. The data is also used in “Understanding the Structural Properties of Moso Bamboo to Engineer Sustainable Structural Bamboo Products” in the 2014 World Conference Engineering Timber Engineering Proceedings. Bamboo is known to have radial and longitudinal density gradients in the tissue. In this study, the microstructural and mechanical aspects of these gradients are the primary focus. Internodes from a single culm of Moso bamboo, obtained from Bamboo Craftsman Company (Portland, Oregon), are used. Microstructural images obtained with scanning electron microscopy (SEM) are used to determine volume fractions and solid fractions of the parenchyma and vascular bundles. These images are given in this dataset. The mechanical properties measured are: the axial Young's modulus in bending, axial modulus of rupture (in bending), axial compressive strength, and radial and tangential compressive strengths. Small mechanical test specimens (for every test type) are cut at different longitudinal (internodes) and radial positions to assess the gradients’ effects on mechanical properties. Raw data from these tests with dimensions, as well as density-property summary files are given in this file. Several readme files are present within the file to explain the structure and organization of the file.This dataset is based upon work supported by the National Science Foundation OISE: 1258574

A protocol for a systematic review of clinical guidelines and published systematic reviews on the early detection of oral cancer

Background: The predicted increase in incidence of oral cavity cancer (OCC) coupled with high mortality and poor prognosis – particularly when diagnosed at a late/advanced stage – highlights the need for prevention and early detection/screening to reverse these trends. Dental healthcare professionals in primary care settings have a pivotal role in this effort. Aim: The aim of this protocol is to detail the process for assessing the evidence for the best practice and methods of early detection/screening for OCC in primary care dental settings by undertaking a systematic review of global clinical guidelines and published systematic reviews. Method: Searches for clinical guidelines and systematic reviews will be conducted in the following databases: Cochrane library, Medical Literature Analysis and Retrieval System Online (Ovid), Excerpta Medical dataBASE, PubMed, Turning Research into Practice, SCOPUS and Web of Science Core Collection. Our search will extend to include Google Scholar and international professional organizations/associations websites. In addition, we will handsearch the bibliographies and undertake citation searches of the selected papers. Quality appraisal will be undertaken using the Appraisal of Guidelines for Research and Evaluation version II instrument for the clinical guidelines and both A MeaSurement Tool to Assess Systematic Reviews and Risk of Bias in Systematic Reviews tools for the systematic reviews. A narrative synthesis approach will be used to assess the evidence of extracted data, primarily taking account of quality appraisal and recency of publication. Discussion: The synthesis of evidence will determine best practice for OCC early detection/screening by primary care dental healthcare professionals and will evaluate the relationship between clinical guidelines and the evidence base available from systematic reviews in this area

Development and mechanical characterization of novel ceramic foams fabricated by gel-casting

Porous ceramic materials are of considerable interest for a variety of chemical and industrial applications in extremely harsh conditions, particularly at very high temperatures for long time periods. A combined gel-casting-fugitive phase process employing agar as a natural gelling agent and polyethylene spheres as pore formers was exploited to produce porous ceramic bodies. Alumina and alumina–zirconia powders were used to prepare samples having a porosity of about 65–70–75 vol%. The composite powder was produced by a surface modification route, i.e. by coating a well-dispersed alpha-alumina powder with a zirconium chloride aqueous solution. On thermal treatment, ultra-fine tetragonal zirconia grains were formed on the surface of the alumina particles. SEM observations and image analysis were used to characterize the microstructure of porous samples and uniaxial compressive tests were carried out to measure their mechanical behavior

The effect of pore size on cell adhesion in collagen-GAG scaffolds.

The biological activity of scaffolds used in tissue engineering applications hypothetically depends on the density of available ligands, scaffold sites at which specific cell binding occurs. Ligand density is characterized by the composition of the scaffold, which defines the surface density of ligands, and by the specific surface area of the scaffold, which defines the total surface of the structure exposed to the cells. It has been previously shown that collagen-glycosaminoglycan (CG) scaffolds used for studies of skin regeneration were inactive when the mean pore size was either lower than 20 microm or higher than 120 microm (Proc. Natl. Acad. Sci., USA 86(3) (1989) 933). To study the relationship between cell attachment and viability in scaffolds and the scaffold structure, CG scaffolds with a constant composition and solid volume fraction (0.005), but with four different pore sizes corresponding to four levels of specific surface area were manufactured using a lyophilization technique. MC3T3-E1 mouse clonal osteogenic cells were seeded onto the four scaffold types and maintained in culture. At the experimental end point (24 or 48 h), the remaining viable cells were counted to determine the percent cell attachment. A significant difference in viable cell attachment was observed in scaffolds with different mean pore sizes after 24 and 48 h; however, there was no significant change in cell attachment between 24 and 48 h for any group. The fraction of viable cells attached to the CG scaffold decreased with increasing mean pore size, increasing linearly (R2 = 0.95, 0.91 at 24 and 48 h, respectively) with the specific surface area of the scaffold. The strong correlation between the scaffold specific surface area and cell attachment indicates that cell attachment and viability are primarily influenced by scaffold specific surface area over this range (95.9-150.5 microm) of pore sizes for MC3T3 cells

Influence of freezing rate on pore structure in freeze-dried collagen-GAG scaffolds.

The cellular structure of collagen-glycosaminoglycan (CG) scaffolds used in tissue engineering must be designed to meet a number of constraints with respect to biocompatibility, degradability, pore size, pore structure, and specific surface area. The conventional freeze-drying process for fabricating CG scaffolds creates variable cooling rates throughout the scaffold during freezing, producing a heterogeneous matrix pore structure with a large variation in average pore diameter at different locations throughout the scaffold. In this study, the scaffold synthesis process was modified to produce more homogeneous freezing by controlling of the rate of freezing during fabrication and obtaining more uniform contact between the pan containing the CG suspension and the freezing shelf through the use of smaller, less warped pans. The modified fabrication technique has allowed production of CG scaffolds with a more homogeneous structure characterized by less variation in mean pore size throughout the scaffold (mean: 95.9 microm, CV: 0.128) compared to the original scaffold (mean: 132.4 microm, CV: 0.185). The pores produced using the new technique appear to be more equiaxed, compared with those in scaffolds produced using the original technique

The effect of pore size on permeability and cell attachment in collagen scaffolds for tissue engineering.

The permeability of scaffolds and other three-dimensional constructs used for tissue engineering applications is important as it controls the diffusion of nutrients in and waste out of the scaffold as well as influencing the pressure fields within the construct. The objective of this study was to characterize the permeability/fluid mobility of collagen-GAG scaffolds as a function of pore size and compressive strain using both experimental and mathematical modeling techniques. Scaffolds containing four distinct mean pore sizes (151, 121, 110, 96 microns) were fabricated using a freeze-drying process. An experimental device was constructed to measure the permeability of the scaffold variants at different levels of compressive strain (0, 14, 29 and 40% while a low-density open-cell foam cellular solids model utilizing a tetrakaidecahedral unit cell was used to accurately model the permeability of each scaffold variant at all level of applied strain. The results of both the experimental and the mathematical analysis revealed that scaffold permeability increases with increasing pore size and decreases with increasing compressive strain. The excellent comparison between experimentally measured and predicted scaffold permeability suggests that cellular solids modelling techniques can be utilized to predict scaffold permeability under a variety of physiological loading conditions as well as to predict the permeability of future scaffolds with a wide variety of pore microstructures

Deep Convolutional Neural Networks for Raman Spectrum Recognition: A Unified Solution

Machine learning methods have found many applications in Raman spectroscopy, especially for the identification of chemical species. However, almost all of these methods require non-trivial preprocessing such as baseline correction and/or PCA as an essential step. Here we describe our unified solution for the identification of chemical species in which a convolutional neural network is trained to automatically identify substances according to their Raman spectrum without the need for preprocessing. We evaluated our approach using the RRUFF spectral database, comprising mineral sample data. Superior classification performance is demonstrated compared with other frequently used machine learning algorithms including the popular support vector machine method

Developing sustainable capacity-building in mental health research: implementation outcomes of training of trainers in systematic reviewing.

Less than 1% of biomedical research papers originate in Africa. Locally relevant mental health research, including synthesis of existing evidence, is essential for developing interventions and strengthening health systems, but institutions may lack the capacity to deliver training on systematic reviewing for publication in international journals. This paper describes the development and implementation of a training-of-trainers (ToT) course on systematic reviewing. The ToT prepared junior faculty ('trainers') from universities in Ethiopia, Malawi, and Zimbabwe to lead a five-day systematic reviewing workshop. Using an evaluation framework based on implementation science outcomes, the feasibility of the ToT was assessed by tracking the number of workshops the trainers subsequently conducted and the number of trainers and trainees who participated; acceptability was assessed through post-workshop surveys on trainee perspectives; impact was evaluated through trainee scores on a 15-item multiple choice test on systematic reviewing concepts; and sustainability was assessed based on whether the workshop was integrated into university curricula. Twelve trainers (86% of those trained) facilitated a total of seven workshops in their home countries (total 103 trainees). The first workshop run in each country was evaluated, and there was a significant improvement in mean knowledge scores between pre- and post-tests among trainees (MD= 3.07, t= 5.90, 95% CI 2.02-4.11). In two of the three countries, there are efforts to integrate the systematic review workshop into university curricula. The cost of the workshop led by the international trainer was $1480 per participant, whereas the trainer-led workshops cost approximately$240 per participant. Overall, ToT is relatively new to research capacity building, although it has been used widely in clinical settings. Our findings suggest ToT is a promising, low-cost way to develop both technical skills of individuals and the pedagogical capacity of universities, and to promote sustainability of research capacity building programs that often have time-limited grant funding

Extended ageing time and temperature effects on quality of sub-primal cuts of boxed beef

[EN]Most of the information indicating ageing improves tenderness has been collected on the loin and rib-eye muscles over relatively short ageing times, assuming that all muscles will react similarly. In the present study, the effect of extended ageing times on instrumental texture (56 d) and sensory characteristics (42 d) of six different beef sub-primals [striploin (SL), inside round (IR), outside round (OR), eye of round (ER), blade eye (BE) and chuck tender (CT)] was studied. The effects of two ageing temperatures (1and 58C) were also compared. In general, ageing increased tenderness (P<0.05) of SL, BE, ER and CT sub-primals, although BE shear force increased after 42 d of ageing. On the other hand, ageing had no effect on IR tenderness (P<0.05) and resulted in a decrease in tenderness of OR (P<0.05) until day 35, with a later increase after 42 d of ageing. Increasing ageing temperature (58C) had limited effect on tenderness, but ageing time and temperature increases led to lower flavour and higher off-flavour intensity (P<0.05) of the studied sub-primals. These results suggest that cutspecific maximum ageing times and rigid adherence to temperature maximums would be of benefit to optimize postslaughter processes and meat quality[FRE]La plupart des données indiquant que le rassissement améliore la tendreté ont été recueillies sur les muscles de la longe et du faux-filet sur un temps relativement court, partant de l’hypothèse que les muscles réagissent tous de la même manière. Cette étude examine l’incidence d’un rassissement prolongé sur la texture (56 jours) et sur les propriétés organoleptiques (42 jours) de six coupes sous-primaires de boeuf [contre-filet (CF), intérieur de ronde (IR), extérieur de ronde (ER), noix de ronde (NR), noix de palette (NP) et bas de tendre (BT)]. Les auteurs ont aussi comparé l’effet de deux températures de rassissement (1et 58C). Dans l’ensemble, le rassissement accroît la tendreté (P<0,05) des morceaux CF, NP, NR et BT, bien que la résistance de la NP au cisaillement augmente après 42 jours. Parallèlement, le rassissement n’a aucune incidence sur la tendreté de l’IR (P<0,05) et diminue celle de l’ER (P<0,05) jusqu’au 35e jour, avant de l’amé liorer passé le 42e jour. Augmenter la température du rassissement (58C) a des effets restreints sur la tendreté , mais ajouteé à un rassissement plus long, la hausse de température atte´nue la saveur et intensifie l’arrière-goût (P<0,05) des pièces de viande examinées. Ces ré sultats laissent croire que l’établissement d’une dureé de rassissement adapteé au morceau et un strict respect de la température maximale optimiseraient les opérations suivant l’abattage et la qualité de la viande

Spatially-localized bench-top X-ray scattering reveals tissue-specific microfibril orientation in Moso bamboo

Background : Biological materials have a complex, hierarchical structure, with vital structural features present at all size scales, from the nanoscale to the macroscale. A method that can connect information at multiple length scales has great potential to reveal novel information. This article presents one such method with an application to the bamboo culm wall. Moso (Phyllostachys edulis) bamboo is a commercially important bamboo species. At the cellular level, bamboo culm wall consists of vascular bundles embedded in a parenchyma cell tissue matrix. The microfibril angle (MFA) in the bamboo cell wall is related to its macroscopic longitudinal stiffness and strength and can be determined at the nanoscale with wide-angle X-ray scattering (WAXS). Combining WAXS with X-ray microtomography (XMT) allows tissue-specific study of the bamboo culm without invasive chemical treatment. Results : The scattering contribution of the fiber and parenchyma cells were separated with spatially-localized WAXS. The fiber component was dominated by a high degree of orientation corresponding to small MFAs (mean MFA 11 degrees). The parenchyma component showed significantly lower degree of orientation with a maximum at larger angles (mean MFA 65 degrees). The fiber ratio, the volume of cell wall in the fibers relative to the overall volume of cell wall, was determined by fitting the scattering intensities with these two components. The fiber ratio was also determined from the XMT data and similar fiber ratios were obtained from the two methods, one connected to the cellular level and one to the nanoscale. X-ray diffraction tomography was also done to study the differences in microfibril orientation between fibers and the parenchyma and further connect the microscale to the nanoscale. Conclusions : The spatially-localized WAXS yields biologically relevant, tissue-specific information. With the custommade bench-top set-up presented, diffraction contrast information can be obtained from plant tissue (1) from regions-of-interest, (2) as a function of distance (line scan), or (3) with two-dimensional or three-dimensional tomography. This nanoscale information is connected to the cellular level features.Peer reviewe