•Using CO2 instead of N2 did not result in any decrease in the yield of biochar.•Biochars had similar fixed-carbon contents and molar H:C and O:C ratios.•The yield of CO significantly increased at ...the expense of the yield of produced CO2.
This study analyzes the effects of using a different atmosphere (pureN2 or pure CO2) at two levels of absolute pressure (0.1 and 1.1MPa) on the pyrolysis of vine shoots at a constant peak temperature of 600°C. Recycling CO2 from residual flue gases into the pyrolysis process may be economically beneficial, since CO2 can replace the use of an expensive N2 environment. In addition, the use of a moderate pressure (e.g., 1.1MPa) can result in higher carbonization efficiencies and an improvement in the pyrolysis gas (in terms of yield and composition). Results from our study suggest that the use of CO2 instead of N2 as pyrolysis environment led to similar carbonization efficiencies (i.e., fixed-carbon yields) and mass yields of biochar. The chemical properties related to the potential stability of biochar (i.e., fixed-carbon content and molar H:C and O:C ratios) were very similar for both pyrolysis atmospheres. Under an atmosphere of CO2, the yield of produced CO2 was drastically decreased at the expense of an increase in the yield of CO, probably as a consequence of the promotion of the reverse Boudouard reaction, especially at high pressure. The enhanced reverse Boudouard reaction can also explain the relatively high BET specific surface area and the macro-porosity development observed for the biochar produced under a CO2 environment at 1.1MPa. In summary, the pressurized pyrolysis of biomass under an atmosphere of CO2 appears as a very interesting route to produce highly stable and porous biochars and simultaneously improving the yield of CO.
We present a new methodology that enables a significant sensitivity improvement for transverse magneto-optical Kerr effect (T-MOKE) detection. For this purpose, we developed a novel measurement ...scheme, in which the polarization detection conditions are changed during the measurement sequence in a pre-defined way. An analytical expression of the associated T-MOKE signal pattern was derived, which allowed us to analyze and classify our experimental data in a straightforward way. Furthermore, this new measurement approach enables the identification of noise and false background signals that might be generated by the sample under investigation, the environment or the detection system itself and it provides a pathway to unambiguously separate all these effects from true T-MOKE signals. These capabilities significantly increase the sensitivity and robustness of T-MOKE detection. The method enabled us to measure magneto-optical signals for samples that are paramagnetic at room temperature or exhibit really small magneto-optical responses, even in the presence of false signals that were far larger in size. Our new methodology was integrated into a scanning wafer tool, which allows for nondestructive, laterally resolved surface characterization measurements and even has the capability of measuring optical and magneto-optical properties simultaneously.
Mechanical stability of epithelia requires firm attachment to the basement membrane via hemidesmosomes. Dysfunction of hemidesmosomal proteins causes severe skin-blistering diseases. Two plakins, ...plectin and BP230 (BPAG1e), link the integrin α6β4 to intermediate filaments in epidermal hemidesmosomes. Here, we show that a linear sequence within the isoform-specific N-terminal region of BP230 binds to the third and fourth FnIII domains of β4. The crystal structure of the complex and mutagenesis analysis revealed that BP230 binds between the two domains of β4. BP230 induces closing of the two FnIII domains that are locked in place by an interdomain ionic clasp required for binding. Disruption of BP230-β4 binding prevents recruitment of BP230 to hemidesmosomes in human keratinocytes, revealing a key role of this interaction for hemidesmosome assembly. Phosphomimetic substitutions in β4 and BP230 destabilize the complex. Thus, our study provides insights into the architecture of hemidesmosomes and potential mechanisms of regulation.
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•Mutual binding sites in integrin α6β4 and BP230 have been identified•Crystal structure of β4-BP230 complex has been solved•Binding of BP230 induces conformation change in β4 as observed by DEER•Binding of BP230 to β4 is necessary for recruitment of BP230 into hemidesmosomes
BP230 connects the integrin α6β4 to intermediate filaments in hemidesmosomes. Manso et al. report the crystal structure of BP230 complexed to β4 and the conformational change in β4 caused by BP230. They identified residues important for binding and propose potential mechanisms of regulation of hemidesmosome assembly and disassembly.
The presence of clustered microcalcifications is one of the earliest signs in breast cancer detection. Although there exist many studies broaching this problem, most of them are nonreproducible due ...to the use of proprietary image datasets. We use a known subset of the currently largest publicly available mammography database, the Digital Database for Screening Mammography (DDSM), to develop a computer-aided detection system that outperforms the current reproducible studies on the same mammogram set. This proposal is mainly based on the use of extracted image features obtained by independent component analysis, but we also study the inclusion of the patient’s age as a nonimage feature which requires no human expertise. Our system achieves an average of 2.55 false positives per image at a sensitivity of 81.8% and 4.45 at a sensitivity of 91.8% in diagnosing the BCRP_CALC_1 subset of DDSM.
Plectin and BPAG1e belong to the plakin family of high-molecular-weight proteins that interconnect the cytoskeletal systems and anchor them to junctional complexes. Plectin and BPAG1e are ...prototypical plakins with a similar tripartite modular structure. The N- and C-terminal regions are built of multiple discrete structural domains, while the central rod domain mediates dimerization by coiled-coil interactions. Owing to the mosaic organization of plakins, the structure of their constituent individual domains or small multi-domain segments can be analyzed isolated. Yet, understanding the integrated function of large regions, oligomers, and heterocomplexes of plakins is difficult due to the large and segmented structure. Here, we describe methods for the production of plectin and BPAG1e samples suitable for structural and biophysical analysis. In addition, we discuss the combination of hybrid methods that yield information at several resolution levels to study the complex, multi-domain, and flexible structure of plakins.
One of the most challenging task for Computer Aided Diagnosis (CADx) systems designed to diagnose breast cancer is to be able to differentiate between benign and malignant masses. In this work we ...present a study made as part of an ongoing project whose aim is to develop an image-based CADx system for diagnosing mass lesions. Our system is based on image-based and non-image features. Image-based features are obtained using Independent Component Analysis (ICA), and both age and mammogram density are tested as non-image features. Performance results are provided for all the valid masses in a public database, obtaining a statistically significant improvement by adding age to image-based features. How- ever, the addition of the density of the mammogram does not improve the system performance.
•A new hygrothermal test procedure based on hot-box apparatus is presented.•The hygrothermal behavior of a multi-holed wall is solved by FEM–DOE–GDO methodology.•This new hybrid method saves a 70% of ...energy and time with respect to current tests.•The numerical and experimental results have shown a very good agreement.
The aim of this paper is the development of a new hybrid methodology to study the moisture transport and heat transfer in masonry structures made up of light concrete hollow bricks (LWHBs) from the numerical and experimental points of view. In order to solve this coupled nonlinear hygrothermal analysis, an instrumented one square meter wall was subjected to eight different moisture stages in the laboratory using a special testing device during a total time of 1480h. In order to simulate the different experimental stages, steady and transient states were implemented in the finite element models. Furthermore, the design of experiments methodology (DOE) and the goal design optimization (GDO) technique are used to calculate the best optimal parameters from the laboratory tests. Once the optimal parameters have been obtained, the finite element models for each stage are solved so that the moisture and temperature distributions were calculated. In this sense, a very good agreement between the numerical and experimental results is achieved. Finally, the most important conclusions of this study and advantages of this new methodology are exposed.
One of the parameters that are usually stored for mammograms is the BI-RADS density, which gives an idea of the breast tissue composition. In this work, we study the effect of BI-RADS density in our ...ongoing project for developing an image-based CAD system to detect masses in mammograms. This system consists of two stages. First, a blind feature extraction is performed for regions of interest (ROIs), using Independent Component Analysis (ICA). Next, in the second stage, those features form the input vectors to a classifier, neural network, or SVM classifier. To train and test our system, the Digital Database for Screening Mammography (DDSM) was used. The results obtained show that the maximum variation in the performance of our system considering only prototypes obtained from mammograms with a concrete value of density (both for training and test) is about 7%, yielding the best values for density equal to 1, and the worst for density equal to 4, for both classifiers. Finally, with the overall results (i.e., using prototypes from mammograms with all the possible values of densities), we obtained a difference in performance that is only 2% lower than the maximum, also for both classifiers.
Integrin α6β4 is a major component of hemidesmosomes that mediate the stable anchorage of epithelial cells to the underlying basement membrane. Integrin α6β4 has also been implicated in cell ...proliferation and migration and in carcinoma progression. The third and fourth fibronectin type III domains (FnIII‐3,4) of integrin β4 mediate binding to the hemidesmosomal proteins BPAG1e and BPAG2, and participate in signalling. Here, it is demonstrated that X‐ray crystallography, small‐angle X‐ray scattering and double electron–electron resonance (DEER) complement each other to solve the structure of the FnIII‐3,4 region. The crystal structures of the individual FnIII‐3 and FnIII‐4 domains were solved and the relative arrangement of the FnIII domains was elucidated by combining DEER with site‐directed spin labelling. Multiple structures of the interdomain linker were modelled by Monte Carlo methods complying with DEER constraints, and the final structures were selected against experimental scattering data. FnIII‐3,4 has a compact and cambered flat structure with an evolutionary conserved surface that is likely to correspond to a protein‐interaction site. Finally, this hybrid method is of general application for the study of other macromolecules and complexes.
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