48 research outputs found
A genome-wide comparison between selected and unselected Valle del Belice sheep reveals differences in population structure and footprints of recent selection
About three decades of breeding and selection in the Valle del Belìce sheep are expected to have left several genomic footprints related to milk production traits. In this study, we have assembled a dataset with 451 individuals of the Valle del Belìce sheep breed: 184 animals that underwent directional selection for milk production and 267 unselected animals, genotyped for 40,660 single-nucleotide polymorphisms (SNPs). Three different statistical approaches, both within (iHS and ROH) and between (Rsb) groups, were used to identify genomic regions potentially under selection. Population structure analyses separated all individuals according to their belonging to the two groups. A total of four genomic regions on two chromosomes were jointly identified by at least two statistical approaches. Several candidate genes for milk production were identified, corroborating the polygenic nature of this trait and which may provide clues to potential new selection targets. We also found candidate genes for growth and reproductive traits. Overall, the identified genes may explain the effect of selection to improve the performances related to milk production traits in the breed. Further studies using high-density array data, would be particularly relevant to refine and validate these results
Homo-PROTACs:bivalent small-molecule dimerizers of the VHL E3 ubiquitin ligase to induce self-degradation
E3 ubiquitin ligases are key enzymes within the ubiquitin proteasome system which catalyze the ubiquitination of proteins, targeting them for proteasomal degradation. E3 ligases are gaining importance as targets to small molecules, both for direct inhibition and to be hijacked to induce the degradation of non-native neo-substrates using bivalent compounds known as PROTACs (for 'proteolysis-targeting chimeras'). We describe Homo-PROTACs as an approach to dimerize an E3 ligase to trigger its suicide-type chemical knockdown inside cells. We provide proof-of-concept of Homo-PROTACs using diverse molecules composed of two instances of a ligand for the von Hippel-Lindau (VHL) E3 ligase. The most active compound, CM11, dimerizes VHL with high avidity in vitro and induces potent, rapid and proteasome-dependent self-degradation of VHL in different cell lines, in a highly isoform-selective fashion and without triggering a hypoxic response. This approach offers a novel chemical probe for selective VHL knockdown, and demonstrates the potential for a new modality of chemical intervention on E3 ligases.Targeting the ubiquitin proteasome system to modulate protein homeostasis using small molecules has promising therapeutic potential. Here the authors describe Homo-PROTACS: small molecules that can induce the homo-dimerization of E3 ubiquitin ligases and cause their proteasome-dependent degradation
Continuous-time model predictive control of food extruder
This paper presents the design and implementation of a continuous-time model predictive controller using Laguerre functions. The application is to control motor torque and specific mechanic energy of an extrusion pilot plant via manipulating screw speed and liquid pump speed. The continuous-time transfer function models are developed using the approach based on state variable filters. The predictive control system is implemented through the existing real-time Supervisory Control And Data Acquisition (SCADA) system in the extruder. Experimental results show satisfactory closed-loop performance of the predictive control system designed
Cation encapsulation within a ten-oxygen spheroidal cavity of conformationally preorganized 1,5-3,7-calix[8]bis-crown-3 derivatives
Conformationally preorganized, D-2d-symmetrical 1,5-3,7-calix[8]bis-crown-3 derivatives have been synthesized which are able to encapsulate cations with a size dependent selectivity
Singly bridged calix[8]crowns
Crowned calix[8]arenes are obtained by direct alkylation of p-tert-butylcalix[8]arene (1) with poly(ethylene glycol) ditosylates in the presence of various bases. K2CO3 promotes the preferential formation of 1,3-calix[8]crowns. Cs2CO3 mainly gives the 1,5-isomers, which are selectively obtained in high yields when shorter chains are used (1,5-crown-2, 88%; 1,5-crown-3, 78%). Nail affords the 1,4-isomers in yields up to 46%, often as the sole crown derivative, besides unreacted 1. 1,2-Calix-[8]crowns are also obtained in appreciable amount in some instances. The observed regioselectivity is rationalized in terms of preferential formation of specific anions in dependence of the base strength. Dynamic NMR and modeling studies prove that the polyether chain, depending on its bridging mode, may significantly reduce the available space for the through the annulus passages leading to derivatives conformationally blocked (on the NMR time scale)
Continuous-time system identification of a food extruder: experiment design and data analysis
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Accelerated Chemical Reaction Optimization Using Multi-Task Learning.
Functionalization of C-H bonds is a key challenge in medicinal chemistry, particularly for fragment-based drug discovery (FBDD) where such transformations require execution in the presence of polar functionality necessary for protein binding. Recent work has shown the effectiveness of Bayesian optimization (BO) for the self-optimization of chemical reactions; however, in all previous cases these algorithmic procedures have started with no prior information about the reaction of interest. In this work, we explore the use of multitask Bayesian optimization (MTBO) in several in silico case studies by leveraging reaction data collected from historical optimization campaigns to accelerate the optimization of new reactions. This methodology was then translated to real-world, medicinal chemistry applications in the yield optimization of several pharmaceutical intermediates using an autonomous flow-based reactor platform. The use of the MTBO algorithm was shown to be successful in determining optimal conditions of unseen experimental C-H activation reactions with differing substrates, demonstrating an efficient optimization strategy with large potential cost reductions when compared to industry-standard process optimization techniques. Our findings highlight the effectiveness of the methodology as an enabling tool in medicinal chemistry workflows, representing a step-change in the utilization of data and machine learning with the goal of accelerated reaction optimization
Accelerated Chemical Reaction Optimization Using Multi-Task Learning
Functionalization of C–H bonds is a key challenge
in medicinal
chemistry, particularly for fragment-based drug discovery (FBDD) where
such transformations require execution in the presence of polar functionality
necessary for protein binding. Recent work has shown the effectiveness
of Bayesian optimization (BO) for the self-optimization of chemical
reactions; however, in all previous cases these algorithmic procedures
have started with no prior information about the reaction of interest.
In this work, we explore the use of multitask Bayesian optimization
(MTBO) in several in silico case studies by leveraging
reaction data collected from historical optimization campaigns to
accelerate the optimization of new reactions. This methodology was
then translated to real-world, medicinal chemistry applications in
the yield optimization of several pharmaceutical intermediates using
an autonomous flow-based reactor platform. The use of the MTBO algorithm
was shown to be successful in determining optimal conditions of unseen
experimental C–H activation reactions with differing substrates,
demonstrating an efficient optimization strategy with large potential
cost reductions when compared to industry-standard process optimization
techniques. Our findings highlight the effectiveness of the methodology
as an enabling tool in medicinal chemistry workflows, representing
a step-change in the utilization of data and machine learning with
the goal of accelerated reaction optimization
NMR Metabolomics Protocols for Drug Discovery
Drug discovery is an extremely difficult and challenging endeavor with a very high failure rate. The task of identifying a drug that is safe, selective and effective is a daunting proposition because disease biology is complex and highly variable across patients. Metabolomics enables the discovery of disease biomarkers, which provides insights into the molecular and metabolic basis of disease and may be used to assess treatment prognosis and outcome. In this regard, metabolomics has evolved to become an important component of the drug discovery process to resolve efficacy and toxicity issues, and as a tool for precision medicine. A detailed description of an experimental protocol is presented that outlines the application of NMR metabolomics to the drug discovery pipeline. This includes: (1) target identification by understanding the metabolic dysregulation in diseases, (2) predicting the mechanism of action of newly discovered or existing drug therapies, (3) and using metabolomics to screen a chemical lead to assess biological activity. Unlike other OMICS approaches, the metabolome is “fragile”, and may be negatively impacted by improper sample collection, storage and extraction procedures. Similarly, biologically-irrelevant conclusions may result from incorrect data collection, pre-processing or processing procedures, or the erroneous use of univariate and multivariate statistical methods. These critical concerns are also addressed in the protocol
Accelerated Chemical Reaction Optimization Using Multi-Task Learning
Functionalization of C–H bonds is a key challenge
in medicinal
chemistry, particularly for fragment-based drug discovery (FBDD) where
such transformations require execution in the presence of polar functionality
necessary for protein binding. Recent work has shown the effectiveness
of Bayesian optimization (BO) for the self-optimization of chemical
reactions; however, in all previous cases these algorithmic procedures
have started with no prior information about the reaction of interest.
In this work, we explore the use of multitask Bayesian optimization
(MTBO) in several in silico case studies by leveraging
reaction data collected from historical optimization campaigns to
accelerate the optimization of new reactions. This methodology was
then translated to real-world, medicinal chemistry applications in
the yield optimization of several pharmaceutical intermediates using
an autonomous flow-based reactor platform. The use of the MTBO algorithm
was shown to be successful in determining optimal conditions of unseen
experimental C–H activation reactions with differing substrates,
demonstrating an efficient optimization strategy with large potential
cost reductions when compared to industry-standard process optimization
techniques. Our findings highlight the effectiveness of the methodology
as an enabling tool in medicinal chemistry workflows, representing
a step-change in the utilization of data and machine learning with
the goal of accelerated reaction optimization