Real‐Time NMR Monitoring of Spatially Segregated Enzymatic Reactions in Multilayered Hydrogel Assemblies**

Compartmentalized chemical reactions at the microscale are important in biotechnology, yet monitoring the molecular content at these small scales is challenging. To address this challenge, we integrate a compact, reconfigurable reaction cell featuring electrochemical functionality with high-resolution NMR spectroscopy. We demonstrate the operation of this system by monitoring the activity of enzymes immobilized in chemically distinct layers within a multi-layered chitosan hydrogel assembly. As a benchmark, we observed the parallel activities of urease (Urs), catalase (Cat), and glucose oxidase (GOx) by monitoring reagent and product concentrations in real-time. Simultaneous monitoring of an independent enzymatic process (Urs) together with a cooperative process (GOx + Cat) was achieved, with chemical conversion modulation of the GOx + Cat process demonstrated by varying the order in which the hydrogel was assembled

Economic globalization and decentralization : a centrifugal or centripetal relationship?

One of the most significant economic trends in the last decades has been the integration of countries in international markets. What have been the consequences of global economic integration upon the territorial organization of the states? Has it contributed to centralize powers or to further decentralization? The literature so far has provided inconclusive evidence. In this paper we shed new light on the relationship between economic globalization and territorial politics by using a varied source of data such as the Regional Authority Index, and the KOF indices of globalization for the period 1970-2010. Results show that economic globalization is positively associated to decentralization, particularly in those countries with more regionalist parties and where levels of inequality are lower. Conversely, higher levels of regional inequality can revert the effect

Video Summarization Using Deep Semantic Features

Computer Vision - ACCV 2016: 13th Asian Conference on Computer Vision, Nov 20-24, 2016, Taipei, TaiwanThis paper presents a video summarization technique for an Internet video to provide a quick way to overview its content. This is a challenging problem because finding important or informative parts of the original video requires to understand its content. Furthermore the content of Internet videos is very diverse, ranging from home videos to documentaries, which makes video summarization much more tough as prior knowledge is almost not available. To tackle this problem, we propose to use deep video features that can encode various levels of content semantics, including objects, actions, and scenes, improving the efficiency of standard video summarization techniques. For this, we design a deep neural network that maps videos as well as descriptions to a common semantic space and jointly trained it with associated pairs of videos and descriptions. To generate a video summary, we extract the deep features from each segment of the original video and apply a clustering-based summarization technique to them. We evaluate our video summaries using the SumMe dataset as well as baseline approaches. The results demonstrated the advantages of incorporating our deep semantic features in a video summarization technique

The acceptance and kinetic resolution of alpha-Methyl Substituted Aldehydes by Norcoclaurine Synthase

Norcoclaurine synthase (NCS) catalyzes a stereoselective Pictet-Spengler reaction to give the key intermediate, (S)-norcoclaurine in benzylisoquinoline alkaloid (BIA) biosynthesis. This family of alkaloids contains many bioactive molecules including morphine and berberine. Recently, NCS has been demonstrated to accept a variety of aldehydes and some ketones as substrates, leading to a range of chiral tetrahydroisoquinoline (THIQ) products. Here, we report the unusual acceptance of a-substituted aldehydes, in particular a-methyl substituted aldehydes, by wild-type Thalictrum flavum NCS (Δ33TfNCS) to give THIQ products. Moreover, the kinetic resolution of several a-substituted aldehydes to give THIQs with two defined chiral centers in a single step with high conversions was achieved. Several dopamine analogues were also accepted as substrates and reactions were amenable to scale-up. Active site mutants of TfNCS were then used which demonstrated the potential to enhance the stereoselectivities in the reaction and improve yields. Rationale for the acceptance of these substrates and improved activity with different mutants has been gained from a co-crystallized structure of Δ33TfNCS with a non-productive mimic of a reaction intermediate bound in the active site. Finally, molecular dynamics simulations were performed to study the binding of dopamine and an a-substituted aldehyde and provided further insight into the reaction with these substrates

Progress and Research Needs of Plant Biomass Degradation by Basidiomycete Fungi

Peer reviewe

Video summarization using deep semantic features

Abstract This paper presents a video summarization technique for an Internet video to provide a quick way to overview its content. This is a challenging problem because finding important or informative parts of the original video requires to understand its content. Furthermore the content of Internet videos is very diverse, ranging from home videos to documentaries, which makes video summarization much more tough as prior knowledge is almost not available. To tackle this problem, we propose to use deep video features that can encode various levels of content semantics, including objects, actions, and scenes, improving the efficiency of standard video summarization techniques. For this, we design a deep neural network that maps videos as well as descriptions to a common semantic space and jointly trained it with associated pairs of videos and descriptions. To generate a video summary, we extract the deep features from each segment of the original video and apply a clustering-based summarization technique to them. We evaluate our video summaries using the SumMe dataset as well as baseline approaches. The results demonstrated the advantages of incorporating our deep semantic features in a video summarization technique

Acceptance and Kinetic Resolution of α-Methyl-Substituted Aldehydes by Norcoclaurine Synthases

Norcoclaurine synthase (NCS) catalyzes a stereoselective Pictet-Spengler reaction to give the key intermediate, (S)-norcoclaurine in benzylisoquinoline alkaloid (BIA) biosynthesis. This family of alkaloids contains many bioactive molecules including morphine and berberine. Recently, NCS has been demonstrated to accept a variety of aldehydes and some ketones as substrates, leading to a range of chiral tetrahydroisoquinoline (THIQ) products. Here, we report the unusual acceptance of α-substituted aldehydes, in particular α-methyl substituted aldehydes, by wild-type Thalictrum flavum NCS (33TfNCS) to give THIQ products. Moreover, the kinetic resolution of several α-substituted aldehydes to give THIQs with two defined chiral centers in a single step with high conversions was achieved. Several dopamine analogues were also accepted as substrates and reactions were amenable to scale-up. Active site mutants of TfNCS were then used which demonstrated the potential to enhance the stereoselectivities in the reaction and improve yields. Rationale for the acceptance of these substrates and improved activity with different mutants has been gained from a co-crystallized structure of 33TfNCS with a non-productive mimic of a reaction intermediate bound in the active site. Finally, molecular dynamics simulations were performed to study the binding of dopamine and an α-substituted aldehyde and provided further insight into the reaction with these substrates

Microfluidics Featuring Multilayered Hydrogel Assemblies Enable Real-Time NMR-Monitoring of Enzyme Cascade Reactions

Compartmentalized chemical reactions at the microscale are interesting from many perspectives including (multi)functional surfaces and biotechnology. Monitoring the molecular content as a measure of functional performance at these small scales is challenging. As a means to address this challenge, we leverage microtechnology and biocompatible materials to integrate a compact, reconfigurable reaction cell featuring electrochemical functionality with high-resolution nuclear magnetic resonance spectroscopy (NMR). We demonstrate the operation of this system by monitoring the activity of enzymes immobilized in chemically distinct layers within a multi-layered chitosan hydrogel assembly. As a benchmark, we observed the parallel activities of urease (Urs), catalase (Cat), and glucose oxidase (GOx) by recording NMR spectra to extract reagent and product concentrations in real-time. As a result, simultaneous monitoring of a cooperative enzymatic process (GOx + Cat) together with an independent process (Urs) is achieved. Using Michaelis-Menten progress curve analysis of the NMR data, kinetic data is extracted: in the case of GOx, the Michaelis constants (KM) are consistent with previous reports, while for Urs, deviations are observed, attributed to an inhibitory effect under our reaction conditions. The system therefore enables the construction of complex reaction cascades with spatial control, as would be interesting in, for example, metabolic engineering and multiplexed sensing applications

The acceptance and kinetic resolution of alpha-Methyl Substituted Aldehydes by Norcoclaurine Synthase

Norcoclaurine synthase (NCS) catalyzes a stereoselective Pictet-Spengler reaction to give the key intermediate, (S)-norcoclaurine in benzylisoquinoline alkaloid (BIA) biosynthesis. This family of alkaloids contains many bioactive molecules including morphine and berberine. Recently, NCS has been demonstrated to accept a variety of aldehydes and some ketones as substrates, leading to a range of chiral tetrahydroisoquinoline (THIQ) products. Here, we report the unusual acceptance of a-substituted aldehydes, in particular a-methyl substituted aldehydes, by wild-type Thalictrum flavum NCS (Δ33TfNCS) to give THIQ products. Moreover, the kinetic resolution of several a-substituted aldehydes to give THIQs with two defined chiral centers in a single step with high conversions was achieved. Several dopamine analogues were also accepted as substrates and reactions were amenable to scale-up. Active site mutants of TfNCS were then used which demonstrated the potential to enhance the stereoselectivities in the reaction and improve yields. Rationale for the acceptance of these substrates and improved activity with different mutants has been gained from a co-crystallized structure of Δ33TfNCS with a non-productive mimic of a reaction intermediate bound in the active site. Finally, molecular dynamics simulations were performed to study the binding of dopamine and an a-substituted aldehyde and provided further insight into the reaction with these substrates