- Bio-regeneration of different rich CO2 absorption solvent via microalgae cultivation. [Journal Article]
- BTBioresour Technol 2019 Jul 10; 290:121781
- As one of the most mature carbon capture technologies, thermal regeneration of rich CO2 absorption solvent is a crucial challenge due to its high energy consumption (typically in the range of 3-6 MJ/…
As one of the most mature carbon capture technologies, thermal regeneration of rich CO2 absorption solvent is a crucial challenge due to its high energy consumption (typically in the range of 3-6 MJ/kg CO2). In this work, a concept of bio-regeneration was proposed using microalgae to convert bicarbonate (which is one of the dominant components in rich solution) into value-added biomass. To evaluate the performance of bio-regeneration, different rich solution (including NH4HCO3, KHCO3 and NaHCO3) were investigated. Experimental results indicated that NH4HCO3 could be a promising bicarbonate carrier for the proposed absorption-microalgae hybrid process, which had a higher biomass productivity (55.36 mg·L-1·d-1) compared to KHCO3 and NaHCO3 and carbon sequestration capacity could be up to 158.3 mg·L-1·d-1. Meanwhile, pH adjustment was an effective approach to further intensify the performance of hybrid process. As a result, bio-regeneration of solvents could be a promising alternative to the conventional thermal regeneration.
- Phenotypes of Gastroesophageal Reflux Disease: Where Rome, Lyon, and Montreal Meet. [Review]
- CGClin Gastroenterol Hepatol 2019 Jul 15
- Gastroesophageal reflux disease (GERD) is now one of the most common diagnoses made in a gastroenterology practice. From a conventional pathophysiological perspective GERD is conceptualized as incomp…
Gastroesophageal reflux disease (GERD) is now one of the most common diagnoses made in a gastroenterology practice. From a conventional pathophysiological perspective GERD is conceptualized as incompetence of the antireflux barrier at the esophagogastric junction; the more severe that incompetence, the worse the disease. However, it is increasingly clear that many presentations of GERD represent distinct phenotypes with unique predisposing cofactors and pathophysiology outside of this paradigm. Three major consensus initiatives have grappled with this dilemma (the Montreal Consensus, The Rome Foundation, and the Lyon Consensus), each from a different perspective. Montreal struggled to define the disease, Rome sought to characterize its "functional" attributes, while Lyon examined its physiological attributes. Our objective in this review is to merge the three, developing the concept that what has come to be known as GERD is actually a family of syndromes with a complex matrix of contributing pathophysiology. A corollary to this is that the concept of one size fits all to therapeutics does not apply and that while escalating treatment with proton pump inhibitors (PPIs) may be pertinent to healing esophagitis, its applicability beyond that is highly questionable. Similarly, failing to recognize the modulating effects of anxiety, hypervigilance, visceral and central hypersensitivity on symptom severity has greatly over-simplified the problem. That over-simplification has led to excessive use of PPIs for everything captured under the GERD umbrella and revealed a broad spectrum of syndromes less amenable to PPI therapy in any dose. It is with this in mind that we delineate this precision medicine concept of GERD.
- The molecular tweezer CLR01 reduces aggregated, pathologic, and seeding-competent α-synuclein in experimental multiple system atrophy. [Journal Article]
- BBBiochim Biophys Acta Mol Basis Dis 2019 Jul 15
- Multiple system atrophy (MSA) is a fatal, adult-onset neurodegenerative disorder that has no cure and very limited treatment options. MSA is characterized by deposition of fibrillar α-synuclein (α-sy…
Multiple system atrophy (MSA) is a fatal, adult-onset neurodegenerative disorder that has no cure and very limited treatment options. MSA is characterized by deposition of fibrillar α-synuclein (α-syn) in glial cytoplasmic inclusions in oligodendrocytes. Similar to other synucleinopathies, α-syn self-assembly is thought to be a key pathologic event and a prominent target for disease modification in MSA. Molecular tweezers are broad-spectrum nanochaperones that prevent formation of toxic protein assemblies and enhance their clearance. The current lead compound, CLR01, has been shown to inhibit α-syn aggregation but has not yet been tested in the context of MSA. To fill this gap, here, we conducted a proof-of-concept study to assess the efficacy of CLR01 in remodeling MSA-like α-syn pathology in the PLP-α-syn mouse model of MSA. Six-month-old mice received intracerebroventricular CLR01 (0.3 or 1 mg/kg per day) or vehicle for 32 days. Open-field test revealed a significant, dose-dependent amelioration of an anxiety-like phenotype. Subsequently, immunohistochemical and biochemical analyses showed dose-dependent reduction of pathological and seeding-competent forms of α-syn, which correlated with the behavioral phenotype. CLR01 treatment also promoted dopaminergic neuron survival in the substantia nigra. To our knowledge, this is the first demonstration of an agent that reduces formation of putative high-molecular-weight oligomers and seeding-competent α-syn in a mouse model of MSA, supporting the view that these species are key to the neurodegenerative process and its cell-to-cell progression in MSA. Our study suggests that CLR01 is an attractive therapeutic candidate for disease modification in MSA and related synucleinopathies, supporting further preclinical development.
- Exploiting Hydrogenophaga pseudoflava for aerobic syngas-based production of chemicals. [Journal Article]
- MEMetab Eng 2019 Jul 15
- Gasification is a suitable technology to generate energy-rich synthesis gas (syngas) from biomass or waste streams, which can be utilized in bacterial fermentation processes for the production of che…
Gasification is a suitable technology to generate energy-rich synthesis gas (syngas) from biomass or waste streams, which can be utilized in bacterial fermentation processes for the production of chemicals and fuels. Established microbial processes currently rely on acetogenic bacteria which perform an energetically inefficient anaerobic CO oxidation and acetogenesis potentially hampering the biosynthesis of complex and ATP-intensive products. Since aerobic oxidation of CO is energetically more favorable, we exploit in this study the Gram-negative β-proteobacterium Hydrogenophaga pseudoflava DSM1084 as novel host for the production of chemicals from syngas. We sequenced and annotated the genome of H. pseudoflava and established a genetic engineering toolbox, which allows markerless chromosomal modification via the pk19mobsacB system and heterologous gene expression on pBBRMCS2-based plasmids. The toolbox was extended by identifying strong endogenous promotors such as PgapA2 which proved to yield high expression under heterotrophic and autotrophic conditions. H. pseudoflava showed relatively fast heterotrophic growth in complex and minimal medium with sugars and organic acids which allows convenient handling in lab routines. In autotrophic bioreactor cultivations with syngas, H. pseudoflava exhibited a growth rate of 0.06 h-1 and biomass specific uptakes rates of 14.2 ± 0.3 mmoL H2 gCDW-1 h-1, 73.9 ± 1.8 mmol CO gCDW-1 h-1, and 31.4 ± 0.3 mmol O2 gCDW-1 h-1. As proof of concept, we engineered the carboxydotrophic bacterium for the aerobic production of the C15 sesquiterpene (E)-α-bisabolene from the C1 carbon source syngas by heterologous expression of the (E)-α-bisabolene synthase gene agBIS. The resulting strain H. pseudoflava (pOCEx1:agBIS) produced 59 ± 8 μg (E)-α-bisabolene L-1 with a volumetric productivity Qp of 1.2 ± 0.2 μg L-1 h-1 and a biomass-specific productivity qp of 13.1 ± 0.6 μg gCDW-1 h-1. The intrinsic properties and the genetic repertoire of H. pseudoflava make this carboxydotrophic bacterium a promising candidate for future aerobic production processes to synthesize more complex or ATP-intensive chemicals from syngas.
- Does mindfulness change the mind? A novel psychonectome perspective based on Network Analysis. [Journal Article]
- PlosPLoS One 2019; 14(7):e0219793
- If the brain is a complex network of functionally specialized areas, it might be expected that mental representations could also behave in a similar way. We propose the concept of 'psychonectome' to …
If the brain is a complex network of functionally specialized areas, it might be expected that mental representations could also behave in a similar way. We propose the concept of 'psychonectome' to formalize the idea of psychological constructs forming a dynamic network of mutually dependent elements. As a proof-of-concept of the psychonectome, networks analysis (NA) was used to explore structural changes in the network of constructs resulting from a psychological intervention. NA was applied to explore the effects of an 8-week Mindfulness-Based Stress Reduction (MBSR) program in healthy participants (N = 182). Psychological functioning was measured by questionnaires assessing five key domains related to MBSR: mindfulness, compassion, psychological well-being, psychological distress and emotional-cognitive control. A total of 25 variables, covering the five constructs, were considered as nodes in the NA. Participants significantly improved in most of the psychological questionnaires. More interesting from a network perspective, there were also significant changes in the topological relationships among the elements. Expected influence and strength centrality indexes revealed that mindfulness and well-being measures were the most central nodes in the networks. The nodes with highest topological change after the MBSR were attentional control, compassion measures, depression and thought suppression. Also, cognitive appraisal, an adaptive emotion regulation strategy, was associated to rumination before the MBSR program but became related to mindfulness and well-being measures after the program. Community analysis revealed a strong topological association between mindfulness, compassion, and emotional regulation, which supports the key role of compassion in mindfulness training. These results highlight the importance of exploring psychological changes from a network perspective and support the conceptual advantage of considering the interconnectedness of psychological constructs in terms of a 'psychonectome' as it may reveal ways of functioning that cannot be analyzed through conventional analytic methods.
- Prediction of ground reaction forces while walking in water. [Journal Article]
- PlosPLoS One 2019; 14(7):e0219673
- Despite being a key concept in rehabilitation, controlling weight-bearing load while walking, following lower limb injury is very hard to achieve. Walking in water provides an opportunity to prescrib…
Despite being a key concept in rehabilitation, controlling weight-bearing load while walking, following lower limb injury is very hard to achieve. Walking in water provides an opportunity to prescribe load for people who have pain, weakness or weight bearing restrictions related to stages of healing. The aim of this experimental study was to evaluate and validate regression models for predicting ground reaction forces while walking in water. One hundred and thirty seven individuals (24±5 years, 1.71±0.08 m and 68.7±12.5 kg) were randomly assigned to a regression group (n = 113) and a validation group (n = 24). Trials were performed at a randomly assigned water depth (0.75 to 1.35 m), and at a self-selected speed. Independent variables were: immersion ratio, velocity, body mass, and waist, thigh and leg circumferences. Stepwise regression was used for the prediction of ground reaction forces and validation included agreement and consistency statistical analyses. Data from a force plate were compared with predicted data from the created model in the validation group. Body mass, immersion ratio, and velocity independently predicted 95% of the vertical and resultant ground reaction force variability, while, together, velocity and thigh circumference explained 81% of antero-posterior ground reaction force variability. When tested against the data measured in validation samples, the models output resulted in statistically similar values, intraclass correlation coefficients ranging from 0.88 to 0.90 and standard errors of measurement, 11.8 to 42.3 N. The models introduced in this study showed good predictive performance in our evaluation procedures and may be considered valid in the prediction of vertical, antero-posterior and resultant ground reaction forces while walking in water. All predictive variables can be easily determined in clinical practice. Future studies should focus on the validation of these models in specific populations.
- Occupational Therapists' Creativity: Tapping Into Client Centeredness Using a Novel Creativity Questionnaire. [Journal Article]
- AJAm J Occup Ther 2019 Jul/Aug; 73(4):7304205110p1-7304205110p8
- CONCLUSIONS: This study supports the importance of creativity in client-centered practice and provides a quantitative measure of this concept, which could be used in future longitudinal studies.
- Exploration of Occupational Deprivation Among Syrian Refugees Displaced in Jordan. [Journal Article]
- AJAm J Occup Ther 2019 Jul/Aug; 73(4):7304205030p1-7304205030p9
- CONCLUSIONS: Further research studies are required to investigate the influence of sociocultural differences on the meaning and consequences of OD. Contextual factors and living difficulties associated with OD need to be further explored.
- Strategy and Methodology in the Synthesis of Multicomponent Molecular Solids: The Quest for Higher Cocrystals. [Journal Article]
- ACAcc Chem Res 2019 Jul 18
- Crystal engineering is the art and science of making crystals by design. Crystallization is inherently a purifying phenomenon. Bringing together more than one organic compound into the same crystal a…
Crystal engineering is the art and science of making crystals by design. Crystallization is inherently a purifying phenomenon. Bringing together more than one organic compound into the same crystal always needs deliberate action. Cocrystals are important because they offer a route to the controlled modulation of crystal properties. The route to cocrystal synthesis was opened up with the heterosynthon concept, which considers the complementary recognition of chemical groups from different molecules. Using this concept, binary cocrystals of enormous variety have been generated, even as crystal engineering has evolved into a form of solid-state supramolecular synthesis. Introducing a third component (a component is somewhat arbitrarily defined as an organic substance that is a solid at room temperature, mostly with the idea of excluding solvates) in a stoichiometric manner requires substantially greater effort and a careful balance of intermolecular interactions-their strengths, directional properties, and distance falloff characteristics. The first systematic ternary cocrystal synthesis was reported around 15 years ago. Drawing in a fourth component in stoichiometric amounts is exceedingly difficult, and we reported such syntheses in 2016. To date, a limited number of ternary cocrystals have been realized (around 120 in all, with a half from our group) and an even smaller number of quaternary cocrystals (around 30, all from our group, barring one). It is impressive that our experiments largely yielded the intended higher cocrystal (three- or four-component) with very small traces of contaminating binaries and pure compounds. A fifth or sixth component may be brought into the solid in the manner of a solid solution in that these components are situated at one of the sites of the quaternary cocrystal. To date, five components have not been included stoichiometrically within the same crystal. This is still an open challenge. The merit in synthesizing (higher) cocrystals is that one can systematically engineer property modularity: Each component is associated with a distinct property. This is important in the pharmaceutical industry, where each component can, in principle, confer a different, desirable property-drug action, solubility, or permeability. However, difficult synthetic targets are also addressed in chemistry simply because they are there. The intellectual satisfaction in making something that is very difficult to make renders the enterprise worthwhile in itself, and new chemistry usually gets uncovered in the process. The development of synthetic organic chemistry can undoubtedly be credited to various reliable methods for chemical transformations, and many difficult total syntheses were achieved by employing these methods over two centuries of research. In contrast, supramolecular synthesis (of multicomponent cocrystals and other assemblies) is in no way at a similar level of sophistication because the subject is still relatively young. Our group and others have reported the synthesis of many higher cocrystals with reliable, reproducible, and robust design strategies. There is a general perception that the isolation of some of these cocrystals is a matter of luck! The crux of this Account is that far from being a serendipitous matter, higher cocrystals may only be made with a judicious combination of strategy and methodology-the essence of synthesis.
New Search Next
- Hydrogen Bond Enhanced Halogen Bonds: A Synergistic Interaction in Chemistry and Biochemistry. [Journal Article]
- ACAcc Chem Res 2019 Jul 18
- The halogen bond (XB) has become an important tool for molecular design in all areas of chemistry, including crystal and materials engineering and medicinal chemistry. Its similarity to the hydrogen …
The halogen bond (XB) has become an important tool for molecular design in all areas of chemistry, including crystal and materials engineering and medicinal chemistry. Its similarity to the hydrogen bond (HB) makes the relationship between these interactions complex, at times competing against and other times orthogonal to each other. Recently, our two laboratories have independently reported and characterized a synergistic relationship, in which the XB is enhanced through direct intramolecular HBing to the electron-rich belt of the halogen. In one study, intramolecular HBing from an amine polarizes the iodopyridinium XB donors of a bidentate anion receptor. The resulting HB enhanced XB (or HBeXB) preorganizes and further augments the XB donors. Consequently, the affinity of the receptor for halogen anions was significantly increased. In a parallel study, a meta-chlorotyrosine was engineered into T4 lysozyme, resulting in a HBeXB that increased the thermal stability and activity of the enzyme at elevated temperatures. The crystal structure showed that the chlorine of the noncanonical amino acid formed a XB to the protein backbone, which augmented the HB of the wild-type enzyme. Calorimetric analysis resulted in an enthalpic contribution of this Cl-XB to the stability of the protein that was an order of magnitude greater than previously determined in biomolecules. Quantum mechanical (QM) calculations showed that rotating the hydroxyl group of the tyrosine to point toward rather than away from the halogen greatly increased its potential to serve as a XB donor, equivalent to what was observed experimentally. In sum, the two systems described here show that the HBeXB concept extends the range of interaction energies and geometries to be significantly greater than that of the XB alone. Additionally, surveys of structural databases indicate that the components for this interaction are already present in many existing molecular systems. The confluence of the independent studies from our two laboratories demonstrates the reach of the HBeXB across both chemistry and biochemistry and that intentional engineering of this enhanced interaction will extend the applications of XBs beyond these two initial examples.