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Novel insights into insect mediated polystyrene biodegradation through bacterial genome analyses
Abstract Plastic pollution is a significant environmental challenge of contemporary age. Polystyrene (PS), among the most commonly used plastic polymers worldwide, is highly durable and difficult to degrade. Despite various disposal strategies, PS continues to impact biodiversity, human health, and ecosystems. Recently, the scientific community has focused on the potential role of microorganisms for plastic biodegradation, particularly those from the gut of plastivorous insects. In a previous study, three bacterial strains, each representing a distinct taxonomic group (Klebsiella, Pseudomonas, and Stenotrophomonas), were isolated from Alphitobius diaperinus larvae after rearing on a PS diet and enriched in a medium with PS as the sole carbon source. The Stenotrophomonas sp. strain, here identified as S. indicatrix, showed the greatest potential for PS degradation. The present study investigates the genetic profile of the newly isolated S. indicatrix strain DAI2m/c through genome sequencing, to identify enzyme-encoding genes involved in the intracellular metabolic pathways responsible for the biodegradation of the styrene monomer. Our findings indicate that the genome of S. indicatrix strain DAI2m/c encodes all enzymes required for one of the two recognized styrene degradation pathways, suggesting its ability to convert styrene into byproducts that are then utilized for cellular energy production.
Cardiovascular-Liver-Metabolic Health: Recommendations in Screening, Diagnosis, and Management of Metabolic Dysfunction-Associated Steatotic Liver Disease in Cardiovascular Disease via Modified Delphi Approach
There is a new awareness of the widespread nature of metabolic dysfunction–associated steatotic liver disease (MASLD) and its connection to cardiovascular disease (CVD). This has catalyzed collaboration between cardiologists, hepatologists, endocrinologists, and the wider multidisciplinary team to address the need for earlier identification of those with MASLD who are at increased risk for CVD. The overlap in the pathophysiologic processes and parallel prevalence of CVD, metabolic syndrome, and MASLD highlight the multisystem consequences of poor cardiovascular–liver–metabolic health. Metabolic dysfunction and associated insulin resistance, together with the predilection for ectopic fat deposition in the liver and surrounding tissues, are associated with elevated risk of endothelial dysfunction, systemic inflammatory response, and ectopic fat deposition in the epicardium. This complex pathophysiology can accelerate atherogenic dyslipidemia, atherogenesis, diastolic dysfunction, valvular calcification, and cardiac arrhythmias. Despite the mounting evidence of mechanistic pathways underpinning MASLD and CVD, current recommendations have not clearly focused upon MASLD as a risk factor or target for intervention in CVD. We have brought together a diverse range of international experts committed to promoting cardiovascular–liver–metabolic health and related outcomes across the globe. The overarching goal of this document is to offer a construct for clinicians in the cardiovascular field with regards to (1) diagnosis and screening of MASLD through the use of noninvasive serum and imaging tests; (2) screening for CVD in all individuals with MASLD regardless of established atherosclerotic risk factors; and (3) the approach to management of MASLD with respect to prevention of CVD through lifestyle, as well as pharmacologic and surgical strategies. To achieve this, the modified Delphi method was applied and a series of evidence-based quality standard recommendations have been identified.
Improving the resilience of urban transportation to natural disasters: the case of Changchun, China
What Is the Mechanism of Atrial Fibrillation Initiation?
Modeling and dynamic analysis of split torsion transmission system considering backlash and center distance errors
Sickle Trait and Alpha Thalassemia Increase NOS-Dependent Vasodilation of Human Arteries Through Disruption of Endothelial Hemoglobin-eNOS Interactions
BACKGROUND: Severe malaria is associated with impaired nitric oxide (NO) synthase (NOS)–dependent vasodilation, and reversal of this deficit improves survival in murine models. Malaria might have selected for genetic polymorphisms that increase endothelial NO signaling and now contribute to heterogeneity in vascular function among humans. One protein potentially selected for is alpha globin, which, in mouse models, interacts with endothelial NOS (eNOS) to negatively regulate NO signaling. We sought to evaluate the impact of alpha globin gene deletions on NO signaling and unexpectedly found human arteries use not only alpha but also beta globin to regulate eNOS. METHODS: The eNOS-hemoglobin complex was characterized by multiphoton imaging, gene expression analysis, and coimmunoprecipitation studies of human resistance arteries. Novel contacts between eNOS and hemoglobin were mapped using molecular modeling and simulation. Pharmacological or genetic disruption of the eNOS-hemoglobin complex was evaluated using pressure myography. The association between alpha globin gene deletion and blood pressure was assessed in a population study. RESULTS: Alpha and beta globin transcripts were detected in the endothelial layer of the artery wall. Imaging colocalized alpha and beta globin proteins with eNOS at myoendothelial junctions. Immunoprecipitation demonstrated that alpha globin and beta globin form a complex with eNOS and cytochrome b5 reductase. Modeling predicted negatively charged glutamic acids at positions 6 and 7 of beta globin to interact with positively charged arginines at positions 97 and 98 of eNOS. Arteries from donors with a glutamic acid–to–valine substitution at beta globin position 6 (sickle trait) exhibited increased NOS-dependent vasodilation. Alpha globin gene deletions were associated with decreased arterial alpha globin expression, increased NOS-dependent vasodilation, and lower blood pressure. Mimetic peptides that targeted the interactions between hemoglobin and eNOS recapitulated the effects of these genetic variants on human arterial vasoreactivity. CONCLUSIONS: Alpha and beta globin subunits of hemoglobin interact with eNOS to restrict NO signaling in human resistance arteries. Malaria-protective genetic variants that alter the expression of alpha globin or the structure of beta globin are associated with increased NOS-dependent vasodilation. Targeting the hemoglobin-eNOS interface could potentially improve NO signaling in diseases of endothelial dysfunction such as severe malaria or chronic cardiovascular conditions.
Experimental study on steady-state operation of organic Rankine cycle system under different operating conditions
Insights into the photocatalytic removal of malachite green organic pollutant by highly efficient hard responsive Ba1 − xCoxDyyFe12−yO19 catalysts
Full-dimensional accurate potential energy surface and dynamics for the unimolecular isomerization reaction CH3NC ⇌ CH3CN
The reaction CH3NC ⇌ CH3CN, a model reaction for the study of unimolecular isomerization, is important in astronomy and atmospheric chemistry and has long been studied by numerous experiments and theories. In this work, we report the first full-dimensional accurate potential energy surface (PES) of this reaction by the permutation invariant polynomial-neural network method based on 30 974 points, whose energies are calculated at the CCSD(T)-F12a/AVTZ level. Then, ring polymer molecular dynamics is used to derive the free energy barrier of the reaction at the experimental temperature range of 472.55–532.92 K. Reaction kinetics are studied at the high-pressure limit and in the fall-off region by standard transition state theory and the master equation, respectively. The calculated temperature- and pressure-dependent rate coefficients are in good agreement with previous experimental and theoretical results. Furthermore, quasi-classical trajectory simulations are performed on this PES to study the intramolecular energy transfer dynamics at initial vibrational energies of 4.336, 5.204, and 6.505 eV.
Efficacy of home based computerized adaptive cognitive training in patients with post stroke cognitive impairment: a randomized controlled trial
TIP 4 P 2005 Ice : Simulating water with two molecular states
Rigid, non-polarizable water models are very efficient from a computational point of view, and some of them have a great ability in predicting experimental properties. There is, however, little room for improvement in simulating water with this strategy, whose main shortcoming is that water molecules do not change their interaction parameters in response to the local molecular landscape. In this work, we propose a novel modeling strategy that involves using two rigid non-polarizable models as states that water molecules can adopt depending on their molecular environment. During the simulation, molecules dynamically transition from one state to another depending on a local order parameter that quantifies some local structural feature. In particular, molecules belonging to low- and high-tetrahedral order environments are represented with the TIP4P/2005 and TIP4P/Ice rigid models, respectively. In this way, the interaction between water molecules is strengthened when they acquire a tetrahedral coordination, which can be viewed as an effective way of introducing polarization effects. We call the resulting model TIP4P2005Ice and show that it outperforms either of the rigid models that build it. This multi-state strategy only slows down simulations by a factor of 1.5 compared to using a standard non-polarizable model and holds great promise for improving simulations of water and aqueous solutions.
Impact of thermal denaturation on renal volume reduction after partial nephrectomy using soft coagulation hemostasis
Polariton spectra under the collective coupling regime. I. Efficient simulation of linear spectra and quantum dynamics
We outline two general theoretical techniques to simulate polariton quantum dynamics and optical spectra under the collective coupling regimes described by a Holstein–Tavis–Cummings (HTC) model Hamiltonian. The first one takes advantage of sparsity of the HTC Hamiltonian, which allows one to reduce the cost of acting polariton Hamiltonian onto a state vector to the linear order of the number of states, instead of the quadratic order. The second one is applying the well-known Chebyshev series expansion approach for quantum dynamics propagation and to simulate the polariton dynamics in the HTC system; this approach allows us to use a much larger time step for propagation and only requires a few recursive operations of the polariton Hamiltonian acting on state vectors. These two theoretical approaches are general and can be applied to any trajectory-based non-adiabatic quantum dynamics methods. We apply these two techniques with our previously developed Lindblad-partially linearized density matrix approach to simulate the linear absorption spectra of the HTC model system, with both inhomogeneous site energy disorders and dipolar orientational disorders. Our numerical results agree well with the previous analytic and numerical work.
External validation of an artificial intelligence model using clinical variables, including ICD-10 codes, for predicting in-hospital mortality among trauma patients: a multicenter retrospective cohort study
Influence of nonequilibrium vibrational dynamics on spin selectivity in chiral molecular junctions
We explore the role of molecular vibrations in the chirality-induced spin selectivity (CISS) effect in the context of charge transport through a molecular nanojunction. We employ a mixed quantum–classical approach that combines Ehrenfest dynamics for molecular vibrations with the hierarchical equations of motion method for the electronic degrees of freedom. This approach treats the molecular vibrations in a nonequilibrium manner, which is crucial for the dynamics of molecular nanojunctions. To explore the effect of vibrational dynamics on spin selectivity, we also introduce a new figure of merit, the displacement polarization, which quantifies the difference in vibrational displacements for opposing lead magnetizations. We analyze the dynamics of single trajectories, investigating how the spin selectivity depends on voltage and electronic–vibrational coupling. Furthermore, we investigate the dynamics and temperature dependence of ensemble-averaged observables. We demonstrate that spin selectivity is correlated in time with the vibrational polarization, indicating that the dynamics of molecular vibrations is the driving force of CISS in this model within the Ehrenfest approach.
Facial features of cartoon characters and their perceived attributes
Photochemical pathways in astronomical ices: A computational study of singlet oxygen reactions with hydrocarbons
Complex organic molecules are widespread in different areas of the interstellar medium, including cold areas, such as molecular clouds, where chemical reactions occur in ice. Among the observed molecules are oxygen-bearing organic molecules, which are of high interest given their significant role in astrobiology. Despite the observed rich chemistry, the underlying molecular mechanisms responsible for molecular formation in such cold dilute areas are still not fully understood. In this paper, we study the unique chemistry taking place in astronomically relevant ices, where UV radiation is a central driving force for chemical reactions. Photofragmentation of ice components gives rise to highly reactive species, such as the O(1D) atom. These species provide a pathway for chemical complexity even in cold areas. Using quantum chemistry calculations, we demonstrate that O(1D) reacts barrierlessly with hydrocarbons. Moreover, photoprocessing of the reaction products (and other components of the ice), followed by radical recombination, is found to be an essential part of the overall mechanism. In ice containing O(1D) and hydrocarbons, the formation of formaldehyde in methane ice, acetaldehyde in ethane ice, and carbon monoxide in acetylene ice, and the consumption of alcohol in all systems, was predicted in agreement with experimental results.
Potential of CoMn2O4 spinel as soot oxidation catalyst and its kinetics thereof
AbstractEfficient catalysts for soot oxidation are critical for mitigating environmental pollution. In this study, CoMn2O4 spinel catalysts were synthesised using reverse co-precipitation and co-precipitation methods to evaluate their performance in soot oxidation and kinetic behaviour. All samples exhibited a tetragonal phase (XRD) and spherical morphology with rough surfaces (SEM). Raman spectroscopy confirmed structural disorder and oxygen vacancies, while XPS analysis revealed the presence of low-valence Mn ions, facilitating oxygen vacancy formation critical for soot oxidation. Additionally, the co-existence of Co and Mn ions contributed to a synergistic effect, enhancing the catalytic properties of the spinel structure. The reverse co-precipitation method produced a catalyst with a higher concentration of oxygen vacancies and active oxygen species among the samples. This sample demonstrated superior catalytic performance, achieving a T50% of 424 °C, low activation energy (153 kJ/mol) and pre-exponential factor (25 min− 1). Soot TPR analysis highlighted the role of catalyst reducibility, while thermogravimetric analysis revealed that activation energy and pre-exponential factors were influenced by surface composition. These findings provide valuable insights into the design of efficient catalysts for soot oxidation, emphasising the importance of synthesis methods and surface characteristics.
Solvatochromic charge model of isonitrile probes for investigating hydrogen-bond dynamics with 2DIR spectroscopy
Isonitrile-derivatized amino acids are emerging as highly effective infrared (IR) probes for investigating the structures and dynamics of hydrogen (H)-bonds. These probes enable the quantification of chemical exchange processes in solute–solvent complexes via two-dimensional IR spectroscopy and hold significant promise for site-specific dynamic studies within proteins. Despite their potential, theoretical models that elucidate the solvatochromism of isonitriles remain underdeveloped. Here, we present the development and validation of a solvatochromic charge model for isonitrile (N≡C) probes. Using density functional theory calculations, we parameterized solvatochromic charges for isonitrile and integrated them into classical molecular dynamics (MD) simulations of β-isocyanoalanine in various solvents, including water and fluorinated alcohols. The model incorporates solvent-induced frequency shifts and accurately reproduces complex experimental line shapes, including asymmetric features from non-Gaussian dynamics. The model successfully reproduced the bimodal distribution of frequency shifts corresponding to free and H-bonded species in alcohols, as well as cross-peaks due to chemical exchange. Achieving reproducibility required long MD trajectories, which were computationally demanding. To manage this, we implemented graphics processing unit acceleration, drastically reducing the computational time and enabling the efficient processing of extensive MD data. While some discrepancies in population ratios suggest the need for refined solvent force field parameters and modeling transition dipole moment variations, the developed solvatochromic model is a reliable tool for studying the solvation dynamics. The model enables more detailed investigations of ultrafast dynamics in solute–solvent complexes and represents important steps toward modeling site-specific dynamics of biomolecules with isonitrile probes.