The functional and biological significance of the selected CASP12 targets are described by the authors of the structures. The crystallographers discuss the most interesting structural features of the target proteins and assess whether these features were correctly reproduced in the predictions submitted to the CASP12 experiment. This article is protected by copyright. All rights reserved.

Spectrochimica Acta Part B: Atomic Spectroscopy, 130 (2017) 35-38. doi:10.1016/j.sab.2017.02.006

Deconstruction of cellulose, the most abundant plant cell wall polysaccharide, requires the cooperative activity of a large repertoire of microbial enzymes. Modular cellulases contain non-catalytic type A Carbohydrate-Binding Modules (CBMs) that specifically bind to the crystalline regions of cellulose, thus promoting enzyme efficacy through proximity and targeting effects. Although type A CBMs play a critical role in cellulose recycling, their mechanism of action remains poorly understood. Here we produced a library of recombinant CBMs representative of the known diversity of type A modules. The binding properties of 40 CBMs, in fusion with an N-terminal green fluorescence protein (GFP) domain, revealed that type A CBMs possess the ability to recognize different crystalline forms of cellulose and chitin over a wide range of temperatures, pHs and ionic strengths. A Spirochaeta thermophila CBM64, in particular, displayed plasticity in its capacity to bind both crystalline and soluble carbohydrates under a wide range of extreme conditions. The structure of S. thermophila StCBM64C revealed an untwisted, flat, carbohydrate-binding interface comprising the side chains of four tryptophan residues in a coplanar linear arrangement. Significantly, two highly conserved asparagine side chains, each one located between two tryptophan residues, are critical to insoluble and soluble glucan recognition but not to bind xyloglucan. Thus, CBM64 compact structure and its extended and versatile ligand interacting platform illustrates how type A CBMs target their appended plant cell wall degrading enzymes to a diversity of recalcitrant carbohydrates under a wide range of environmental conditions.

This paper focuses on the analysis of InGaZnO thin-film transistors (TFTs) and circuits under the influence of different temperatures and bias stress, shedding light into their robustness when used in real-world applications. For temperature-dependent measurements, a temperature range of 15 to 85 • C was considered. In case of bias stress, both gate and drain bias were applied for 60 min. Though isolated transistors show a variation of drain current as high as 56% and 172% during bias voltage and temperature stress, the employed circuits were able to counteract it. Inverters and two-TFT current mirrors following simple circuit topologies showed a gain variation below 8%, while the improved robustness of a cascode current mirror design is proven by showing a gain variation less than 5%. The demonstration that the proper selection of TFT materials and circuit topologies results in robust operation of oxide electronics under different stress conditions and over a reasonable range of temperatures proves that the technology is suitable for applications such as smart food packaging and wearables.

A utilização de Polímeros Reforçados com Fibras (FRP) no reforço de estruturas de Betão Armado (BA) tem tido cada vez mais aceitação devido à sua elevada resistência e rigidez, baixo peso específico e excelente resistência aos efeitos dos agentes ambientais. No entanto, actualmente, é comum utilizarem-se técnicas de reforço que dificilmente permitem tirar partido da resistência total destes materiais. Com o objectivo de explorar a capacidade total de Polímeros Reforçados com Fibras de Carbono (CFRP), foram estudadas e desenvolvidas duas novas técnicas de reforço de vigas à flexão designadas por Continuous Reinforcement Embedded at Ends (CREatE) e Horizontal Near Surface Mounted Reinforcement (HNSMR). Posteriormente realizou-se um estudo comparativo entre o desempenho destes sistemas de reforço e o de duas outras técnicas já estudadas e usuais, nomeadamente os sistemas Externally Bonded Reinforcement (EBR) e Near Surface Mounted Reinforcement (NSMR). A técnica CREatE provou ser a mais eficaz de todas as alternativas testadas mobilizando a totalidade do compósito de CFRP e dotando as vigas de BA com uma maior capacidade resistente e com uma ductilidade mais elevada.Como complemento deste trabalho experimental, desenvolveu-se também um programa de cálculo em MATLAB, capaz de simular o problema em estudo através de um modelo numérico de análise não linear através do equilíbrio de secções. A representatividade dos dados obtidos foi verificada através de uma análise comparativa entre os valores numéricos e os obtidos experimentalmente.The use of Fiber Reinforced Polymers (FRP) in order to strengthen Reinforced Concrete (RC) structures has been increasingly accepted due to their strength and stiffness, low weight and excellent resistance to the effects of environmental aggressive agents. However, the bonding techniques available and described in the literature can not allow the full use of the mechanical properties of these materials and premature failures are often observed and described by several researchers. In order to explore the full capacity of CFRP composites, two new bonding strengthening techniques of RC beams when subjected to 4-point bending tests were studied and developed. For these new techniques, the designation of Continuous Reinforcement Embedded at Ends (CREatE) and Horizontal Near Surface Mounted Reinforcement (HNSMR) has been assigned. Posteriorly, a comparative study has been carried out between those strengthening systems performance and two traditional techniques, namely, the Externally Bonded Reinforcement (EBR) and Near Surface Mounted Reinforcement (NSMR). The CREatE technique has proved to be the most effective of all alternatives tested, with the full utilization of the CFRP composite and the highest strength, combined with the highest ductility. A code using MATLAB software was developed as a complement of this experimental work, which is able to simulate the problem under study through a nonlinear numerical model based on the equilibrium of sections. The representativeness of the numerical data has been verified afterwards through a comparative analysis between those and the experimental results.

Despite the success of exploiting the properties of amorphous oxide semiconductors for device applications, the charge transport in these materials is still not clearly understood. The observation of a definite Hall voltage suggests that electron transport in the conduction band is free-electron-like. However, the temperature dependence of the Hall and field-effect mobilities cannot be explained using a simple bandlike model. Here, we perform gated Hall effect measurements in field-effect transistors, which allow us to make two independent estimates of the charge carrier concentration and determine the Hall factor providing information on the energy dependence of the relaxation time. We demonstrate that the Hall factor in a range of sputtered and solution-processed quaternary amorphous oxides, such as a-InGaZnO, is close to two, while in ternary oxides, such as InZnO, it is near unity. This suggests that quaternary elements like Ga act as strong ionized impurity scattering centers in these materials.

The employment of printing techniques as cost-effective methods to fabricate low cost, flexible, disposable and sustainable solar cells is intimately dependent on the substrate properties and the adequate electronic devices to be powered by them. Among such devices, there is currently a growing interest in the development of user-oriented and multipurpose systems for intelligent packaging or on-site medical diagnostics, which would greatly benefit from printable solar cells as their energy source for autonomous operation. This chapter first describes and analyzes different types of cellulose-based substrates for flexible and cost effective optoelectronic and bio devices to be powered by printed solar cells. Cellulose is one of the most promising platforms for green recyclable electronics and it is fully compatible with large-scale printing techniques, although some critical requirements must be addressed. Paper substrates exist in many forms. From common office paper, to packaging cardboard used in the food industry, or nanoscale engineered cellulose (e.g. bacterial cellulose). However, it is the structure and content of paper that determines its end use. Secondly, proof-of-concept of optoelectronic and bio devices pro-duced by inkjet printing are described and show the usefulness of solar cells as a power source or as a chemical reaction initiator for sensors.

Chemical solution deposition is a low cost, scalable and high performance technique to obtain metal oxide thin films. Recently, solution combustion synthesis has been introduced as a chemical route to reduce the processing temperature. This synthesis method takes advantage of the chemistry of the precursors as a source of energy for localized heating. According to the combustion chemistry some organic solvents can have a dual role in the reaction, acting both as solvent and fuel. In this work, we studied the role of 2-methoxyethanol in solution based synthesis of ZTO thin films and its influence on the performance of ZTO TFTs. The thermal behaviour of ZTO precursor solutions confirmed that 2-methoxyethanol acts simultaneously as a solvent and fuel, replacing the fuel function of urea. The electrical characterization of the solution based ZTO TFTs showed a slightly better performance and lower variability under positive gate bias stress when urea was not used as fuel, confirming that the excess fuel contributes negatively to the device operation and stability. Solution based ZTO TFTs demonstrated a low hysteresis ($Δ$V = −0.3 V) and a saturation mobility of 4–5 cm2 V−1 s−1.

In this paper we deal with analog active filter design using discrete components taking into consideration tolerance effects. Sensitivity analysis is performed to determine the most influential components in the considered circuit, thus relative higher precision is offered to those parameters. Further, an in-loop optimization technique is considered, thus actual IC models are handled. An application example is presented. HSpice simulation results, supported by Monte Carlo analysis, are given to highlight efficiency of the proposed selection technique.

There are many different ways to reduce the construction industry's impact on environment. The incorporation of waste in the fabrication of construction materials may be beneficial for both the waste management sector and the construction industry. The aim of this research was to investigate the use of three different waste materials (construction and demolition waste, brick powder and fly ash) as filler in asphalt mixtures. Limestone filler was used as reference material. The materials were characterized in terms of their geometrical, physical and chemical properties, and the interaction with bitumen was assessed with two mastic test methods using four different bitumens. The specific surface of waste materials shows a wide-ranging variation due to material specific shape and texture of particles. However, the Rigden voids and bitumen number tests adequately measure the stiffening effect of these materials. The delta ring and ball test results showed there is a good relation with the filler content when the results are affected by the bitumen type. The f/b ratio for a specific bitumen–filler combination can be determined from the maximum filler-to-bitumen ratio and the recommended stiffening increase. The mastics with these waste materials showed strong resistance to water damage.

Piezoelectric energy harvesting has received great attention over the last 20 years. The main goal of this work is to discuss the potential advantages of introducing non-linearities in the dynamics of a beam type piezoelectric vibration energy harvester. The described device is essentially a cantilever beam partially covered by piezoelectric material with a force electromagnetically applied to the beam. Through experimental tests it has been confirmed the benefits of introducing non-linearities in these types of systems.

Cellulosomes are sophisticated multi-enzymatic nanomachines produced by anaerobes to effectively deconstruct plant structural carbohydrates. Cellulosome assembly involves the binding of enzyme-borne dockerins (Doc) to repeated cohesin (Coh) modules located in a non-catalytic scaffoldin. Docs appended to cellulosomal enzymes generally present two similar Coh-binding interfaces supporting a dual-binding mode, which may confer increased positional adjustment of the different complex components. Ruminococcus flavefaciens’ cellulosome is assembled from a repertoire of 223 Doc-containing proteins classified into 6 groups. Recent studies revealed that Docs of groups 3 and 6 are recruited to the cellulosome via a single-binding mode mechanism with an adaptor scaffoldin. To investigate the extent to which the single-binding mode contributes to the assembly of R. flavefaciens cellulosome, the structures of two group 1 Docs bound to Cohs of primary (ScaA) and adaptor (ScaB) scaffoldins were solved. The data revealed that group 1 Docs display a conserved mechanism of Coh recognition involving a single-binding mode. Therefore, in contrast to all cellulosomes described to date, the assembly of R. flavefaciens cellulosome involves single but not dual-binding mode Docs. Thus, this work reveals a novel mechanism of cellulosome assembly and challenges the ubiquitous implication of the dual-binding mode in the acquisition of cellulosome flexibility.

n/a