Unlocking lager's flavour palette by metabolic engineering of Saccharomyces pastorianus for enhanced ethyl ester production.

Despite being present in trace amounts, ethyl esters play a crucial role as flavour compounds in lager beer. In yeast, ethyl hexanoate, ethyl octanoate and ethyl decanoate, responsible for fruity and floral taste tones, are synthesized from the toxic medium chain acyl-CoA intermediates released by the fatty acid synthase complex during the fatty acid biosynthesis, as a protective mechanism. The aim of this study was to enhance the production of ethyl esters in the hybrid lager brewing yeast Saccharomyces pastorianus by improving the medium chain acyl-CoA precursor supply.

Draft genome sequence of the Cas9 expressing strain IMX2600, a laboratory and platform strain from the CEN.PK lineage for cell-factory research.

The biobased-economy aims to create a circular biotechnology ecosystem to transition from a fossil fuel-based to a sustainable industry based on biomass. For this, new microbial cell-factories are essential. We present the draft genome of the CEN.

Expanding the genome editing toolbox of Saccharomyces cerevisiae with the endonuclease ErCas12a.

ErCas12a is a class 2 type V CRISPR-Cas nuclease isolated from Eubacterium rectale with attractive fundamental characteristics, such as RNA self-processing capability, and lacks reach-through royalties typical for Cas nucleases. This study aims to develop a ErCas12a-mediated genome editing tool applicable in the model yeast Saccharomyces cerevisiae. The optimal design parameters for ErCas12a editing in S.

Improving CRISPR-Cas9 mediated genome integration in interspecific hybrid yeasts.

Saccharomyces pastorianus is not a classical taxon, it is an interspecific hybrid resulting from the cross of Saccharomyces cerevisiae and Saccharomyces eubayanus. Exhibiting heterosis for phenotypic traits such as wort α-oligosaccharide consumption and fermentation at low temperature, it has been domesticated to become the main workhorse of the brewing industry. Although CRISPR-Cas9 has been shown to be functional in S.

A high birefringence liquid crystal for lenses with large aperture.

This work presents the application of an experimental nematic liquid crystal (LC) mixture (1929) in a large aperture lens. The LC material is composed of terphenyl and biphenyl derivatives compounds with an isothiocyanate terminal group and fluorinated lateral substituents. The substitution with a strongly polar isothiocyanate group and an aromatic rigid core provides [Formula: see text]-electron coupling, providing high birefringence ([Formula: see text] at 636 nm and 23 °C) and low viscosity ([Formula: see text] = 17.

Aspherical liquid crystal lenses based on a variable transmission electrode.

In this work, a technique to generate aspherical liquid crystal lenses with positive and negative optical power is experimentally demonstrated. The main enabling element is a micro-metric electrode with variable spatial size. This produces a decreasing resistance towards the lens centre that generates the desired voltage/phase profiles.

Electro-Optical and Photo Stabilization Study of Nematic Ternary Mixture.

Liquid crystal materials composed of mixed nematic compounds find broad use in liquid crystal displays and photonic applications. A ternary mixture formed from three different nematic compounds shows peculiar behavior such as tunable electro-optical properties dependent on the frequency of the driving voltage. The paper presents an analysis of the response time and phase retardation of a frequency tunable nematic liquid crystal mixture (under code name 5005).

gEL DNA: A Cloning- and Polymerase Chain Reaction-Free Method for CRISPR-Based Multiplexed Genome Editing.

Even for the genetically accessible yeast , the CRISPR-Cas DNA editing technology has strongly accelerated and facilitated strain construction. Several methods have been validated for fast and highly efficient single editing events, and diverse approaches for multiplex genome editing have been described in the literature by means of Cas9 or Cas12a endonucleases and their associated guide RNAs (gRNAs). The gRNAs used to guide the Cas endonuclease to the editing site are typically expressed from plasmids using native Pol II or Pol III RNA polymerases.

Multifunctional light beam control device by stimuli-responsive liquid crystal micro-grating structures.

There is an increasing need to control light phase with tailored precision via simple means in both fundamental science and industry. One of the best candidates to achieve this goal are electro-optical materials. In this work, a novel technique to modulate the spatial phase profile of a propagating light beam by means of liquid crystals (LC), electro-optically addressed by indium-tin oxide (ITO) grating microstructures, is proposed and experimentally demonstrated.

Positive-negative tunable liquid crystal lenses based on a microstructured transmission line.

In this work, a novel technique to create positive-negative tunable liquid crystal lenses is proposed and experimentally demonstrated. This structure is based on two main elements, a transmission line acting as a voltage divider and concentric electrodes that distribute the voltage homogeneously across the active area. This proposal avoids all disadvantages of previous techniques, involving much simpler fabrication process (a single lithographic step) and voltage control (one or two sources).

The Young Interferometer as an Optical System for a Variable Depolarizer Characterization.

This article proposes an interferometric method for a variable depolarizer characterization with features that distinguish it from the polarimetric system. Information about the behavior of a vertically aligned nematic cell as a variable depolarizer can be extracted from Young interferometer measurements in real time. These results could be significant for understanding the polarization phenomena in depolarizing media such as biological tissue.

Tunable liquid crystal multifocal microlens array.

A novel liquid crystal microlens array with tunable multifocal capability, high optical power and fill-factor is proposed and experimentally demonstrated. A specific hole pattern design produces a multifocal array with only one voltage control. Three operations modes are possible, "Off", "Tunable Multifocal" and "Unifocal".

Low aberration and fast switching microlenses based on a novel liquid crystal mixture.

In this work, we present a novel kind of LC mixture (5005) for photonic applications, with emphasis on a LC microlens array. This mixture is a nematic composition of three different families of rod like liquid crystals. The key is that frequency dependence of parallel component of electric permittivity is different for each component, resulting in a strongly dependent on frequency dielectric anisotropy.

Liquid crystal spherical microlens array with high fill factor and optical power.

A novel liquid crystal spherical microlens array with high optical power and almost 100% of fill-factor is proposed and experimentally demonstrated. The combination of a specific structure and electrical waveforms applied to the electrodes generates an array of spherical microlenses with square aperture. The manufacturing process is simple (patterned electrodes) and the microlenses are reconfigurable by low voltage signals (the electrodes are in contact with the LC layer).

Morphology of SiO films as a key factor in alignment of liquid crystals with negative dielectric anisotropy.

Control of liquid crystal (LC) orientation using a proper SiO alignment layer is essential for the optimization of vertically aligned nematic (VAN) displays. With this aim, we studied the optical anisotropy of thin SiO films by generalized ellipsometry as a function of deposition angle. The columnar SiO structure orientation measured by a noninvasive ellipsometry technique is reported for the first time, and its morphology influence on the LC alignment is demonstrated for large deposition angles.

Tunable liquid crystal cylindrical micro-optical array for aberration compensation.

A tunable aberration compensation device for rectangular micro-optical systems is proposed and demonstrated. This device, which is based in nematic liquid crystal and a micro-electrode structure, forms gradients in the index of refraction as a function of voltage. We have developed a fringe skeletonizing application in order to extract the 3D wavefront from an interference pattern.

Modal liquid crystal microaxicon array.

A novel tunable liquid crystal microaxicon array is proposed and experimentally demonstrated. The proposed structure is capable of generating tunable axicons (thousands of elements) of micrometric size, with simple control (four control voltages) and low voltage, and is totally reconfigurable. Depending on the applied voltages, control over the diameter, as well as the effective wedge angle, can be achieved.

Improving the Pass-Band Return Loss in Liquid Crystal Dual-Mode Bandpass Filters by Microstrip Patch Reshaping.

In this paper, the design and experimental characterization of a tunable microstrip bandpass filter based on liquid crystal technology are presented. A reshaped microstrip dual-mode filter structure has been used in order to improve the device performance. Specifically, the aim is to increase the pass-band return loss of the filter by narrowing the filter bandwidth.

A novel high-sensitivity, low-power, liquid crystal temperature sensor.

A novel temperature sensor based on nematic liquid crystal permittivity as a sensing magnitude, is presented. This sensor consists of a specific micrometric structure that gives considerable advantages from other previous related liquid crystal (LC) sensors. The analytical study reveals that permittivity change with temperature is introduced in a hyperbolic cosine function, increasing the sensitivity term considerably.

Point diffraction interferometer with a liquid crystal monopixel.

In this work a novel point diffraction interferometer based on a variable liquid crystal wave plate (LCWP) has been implemented. The LCWP consists of a 3x3 cm(2) monopixel cell with parallel alignment. The monopixel cell was manufactured such that the electrode covers the entire surface except in a centered circular area of 50 μm of diameter.

Hand orientation for grasping and arm joint rotation patterns in healthy subjects and hemiparetic stroke patients.

We previously demonstrated that the hand orientation for grasping (azimuth) is strongly coupled to arm movement direction in the horizontal plane. The question is whether this coupling is directly controlled or secondary to a regulation of the arm angular configuration. To this purpose, we quantified hand orientation and arm joint rotations during unconstrained reaching movements in healthy subjects and in patients with hemiparesis due to stroke since they use altered joint rotation patterns for reaching.

Coupling between reaching movement direction and hand orientation for grasping.

In a previous work, we demonstrated that orientation of the hand in the horizontal plane (azimuth) at the time of grasping depends on the direction of the reaching movement in the horizontal plane. Here we report three experiments to further investigate the generality of this coupling. Azimuth of the hand for grasping was studied while subjects were reaching for objects placed at various locations on a horizontal board.