Inverse gas chromatography (IGC) is a versatile, powerful, sensitive and relatively fast technique for characterizing the physicochemical properties of materials. Due to its applicability in ...determining surface properties of solids in any form such as films, fibres and powders of both crystalline and amorphous structures, IGC became a popular technique for surface characterization, used extensively soon after its development. One of the most appealing features of IGC that led to its popularity among analytical scientists in early years was its similarity in principle to analytical gas chromatography (GC). The main aspect which distinguishes IGC experiments from conventional GC is the role of mobile and stationary phases. Contrary to conventional GC, the material under investigation is placed in the chromatographic column and a known probe vapour is used to provide information on the surface.
In this review, information concerning the history, instrumentation and applications is discussed. Examples of the many experiments developed for IGC method are selected and described. Materials that have been analysed include polymers, pharmaceuticals, minerals, surfactants, and nanomaterials. The properties that can be determined using the IGC technique include enthalpy and entropy of sorption, surface energy (dispersive and specific components), work of co/adhesion, miscibility and solubility parameters, surface heterogeneity, glass transition temperature, and specific surface area.
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•Inverse gas chromatography is a powerful tool in characterizing surfaces.•Dispersive and specific components of surface energy can be measured.•A wide variety of materials have been investigated over the years.•Review of the technique and past research has been conducted.
Lipid-polymer hybrid nanoparticles (LPHNPs) are next-generation core-shell nanostructures, conceptually derived from both liposome and polymeric nanoparticles (NPs), where a polymer core remains ...enveloped by a lipid layer. Although they have garnered significant interest, they remain not yet widely exploited or ubiquitous. Recently, a fundamental transformation has occurred in the preparation of LPHNPs, characterized by a transition from a two-step to a one-step strategy, involving synchronous self-assembly of polymers and lipids. Owing to its two-in-one structure, this approach is of particular interest as a combinatorial drug delivery platform in oncology. In particular, the outer surface can be decorated in multifarious ways for active targeting of anticancer therapy, delivery of DNA or RNA materials, and use as a diagnostic imaging agent. This review will provide an update on recent key advancements in design, synthesis, and bioactivity evaluation as well as discussion of future clinical possibilities of LPHNPs.
Ebola virus disease (EVD) often leads to severe and fatal outcomes in humans with early supportive care increasing the chances of survival. Profiling the human plasma lipidome provides insight into ...critical illness as well as diseased states, as lipids have essential roles as membrane structural components, signaling molecules, and energy sources. Here we show that the plasma lipidomes of EVD survivors and fatalities from Sierra Leone, infected during the 2014–2016 Ebola virus outbreak, were profoundly altered. Focusing on how lipids are associated in human plasma, while factoring in the state of critical illness, we found that lipidome changes were related to EVD outcome and could identify states of disease and recovery. Specific changes in the lipidome suggested contributions from extracellular vesicles, viremia, liver dysfunction, apoptosis, autophagy, and general critical illness, and we identified possible targets for therapies enhancing EVD survival.
We investigated disparities in the clinical management of self-harm following hospital presentation with self-harm according to level of socio-economic deprivation (SED) in England.
108 092 ...presentations to hospitals (by 57 306 individuals) after self-harm in the Multicenter Study of Self-harm spanning 17 years. Area-level SED was based on the English Index of Multiple Deprivation. Information about indicators of clinical care was obtained from each hospital's self-harm monitoring systems. We assessed the associations of SED with indicators of care using mixed effect models.
Controlling for confounders, psychosocial assessment and admission to a general medical ward were less likely for presentations by patients living in more deprived areas relative to presentations by patients from the least deprived areas. Referral for outpatient mental health care was less likely for presentations by patients from the two most deprived localities (most deprived: adjusted odd ratio aOR 0.77, 95% CI 0.71-0.83,
< 0.0001; 2nd most deprived: aOR 0.80, 95% CI 0.74-0.87,
< 0.0001). Referral to substance use services and 'other' services increased with increased SED. Overall, referral for aftercare was less likely following presentations by patients living in the two most deprived areas (most deprived: aOR 0.85, 95% CI 0.78-0.92,
< 0.0001; 2nd most deprived: aOR 0.86, 95% CI 0.79-0.94,
= 0.001).
SED is associated with differential care for patients who self-harm in England. Inequalities in care may exacerbate the risk of adverse outcomes in this disadvantaged population. Further work is needed to understand the reasons for these differences and ways of providing more equitable care.
Treatments for 'superbug' infections are the focus for innovative research, as drug resistance threatens human health and medical practices globally. In particular, Acinetobacter baumannii (Ab) ...infections are repeatedly reported as difficult to treat due to increasing antibiotic resistance. Therefore, there is increasing need to identify novel targets in the development of different antimicrobials. Of particular interest is fatty acid synthesis, vital for the formation of phospholipids, lipopolysaccharides/lipooligosaccharides, and lipoproteins of Gram-negative envelopes. The bacterial type II fatty acid synthesis (FASII) pathway is an attractive target for the development of inhibitors and is particularly favourable due to the differences from mammalian type I fatty acid synthesis. Discrete enzymes in this pathway include two reductase enzymes: 3-oxoacyl-acyl carrier protein (ACP) reductase (FabG) and enoyl-ACP reductase (FabI). Here, we investigate annotated FabG homologs, finding a low-molecular weight 3-oxoacyl-ACP reductase, as the most likely FASII FabG candidate, and high-molecular weight 3-oxoacyl-ACP reductase (HMwFabG), showing differences in structure and coenzyme preference. To date, this is the second bacterial high-molecular weight FabG structurally characterized, following FabG4 from Mycobacterium. We show that ΔAbHMwfabG is impaired for growth in nutrient rich media and pellicle formation. We also modelled a third 3-oxoacyl-ACP reductase, which we annotated as AbSDR. Despite containing residues for catalysis and the ACP coordinating motif, biochemical analyses showed limited activity against an acetoacetyl-CoA substrate in vitro. Inhibitors designed to target FabG proteins and thus prevent fatty acid synthesis may provide a platform for use against multidrug-resistant pathogens including A. baumannii.
Abstract
We present an in-depth analysis of gas morphologies for a sample of 25 Milky Way–like galaxies from the IllustrisTNG TNG50 simulation. We constrain the morphology of cold, warm, hot gas, and ...gas particles as a whole using a local shell iterative method and explore its observational implications by computing the hard-to-soft X-ray ratio, which ranges between 10
−3
and 10
−2
in the inner ∼50 kpc of the distribution and 10
−5
–10
−4
at the outer portion of the hot gas distribution. We group galaxies into three main categories: simple, stretched, and twisted. These categories are based on the radial reorientation of the principal axes of the reduced inertia tensor. We find that a vast majority (77%) of the galaxies in our sample exhibit twisting patterns in their radial profiles. Additionally, we present detailed comparisons between (i) the gaseous distributions belonging to individual temperature regimes, (ii) the cold gas distributions and stellar distributions, and (iii) the gaseous distributions and dark matter (DM) halos. We find a strong correlation between the morphological properties of the cold gas and stellar distributions. Furthermore, we find a correlation between gaseous distributions with a DM halo that increases with gas temperature, implying that we may use the warm–hot gaseous morphology as a tracer to probe the DM morphology. Finally, we show gaseous distributions exhibit significantly more prolate morphologies than the stellar distributions and DM halos, which we hypothesize is due to stellar and active galactic nucleus feedback.
Nearly half of the earth's photosynthetically fixed carbon derives from the oceans. To determine global and region specific rates, we rely on models that estimate marine net primary productivity ...(NPP) thus it is essential that these models are evaluated to determine their accuracy. Here we assessed the skill of 21 ocean color models by comparing their estimates of depth-integrated NPP to 1156 in situ 14C measurements encompassing ten marine regions including the Sargasso Sea, pelagic North Atlantic, coastal Northeast Atlantic, Black Sea, Mediterranean Sea, Arabian Sea, subtropical North Pacific, Ross Sea, West Antarctic Peninsula, and the Antarctic Polar Frontal Zone. Average model skill, as determined by root-mean square difference calculations, was lowest in the Black and Mediterranean Seas, highest in the pelagic North Atlantic and the Antarctic Polar Frontal Zone, and intermediate in the other six regions. The maximum fraction of model skill that may be attributable to uncertainties in both the input variables and in situ NPP measurements was nearly 72%. On average, the simplest depth/wavelength integrated models performed no worse than the more complex depth/wavelength resolved models. Ocean color models were not highly challenged in extreme conditions of surface chlorophyll-a and sea surface temperature, nor in high-nitrate low-chlorophyll waters. Water column depth was the primary influence on ocean color model performance such that average skill was significantly higher at depths greater than 250 m, suggesting that ocean color models are more challenged in Case-2 waters (coastal) than in Case-1 (pelagic) waters. Given that in situ chlorophyll-a data was used as input data, algorithm improvement is required to eliminate the poor performance of ocean color NPP models in Case-2 waters that are close to coastlines. Finally, ocean color chlorophyll-a algorithms are challenged by optically complex Case-2 waters, thus using satellite-derived chlorophyll-a to estimate NPP in coastal areas would likely further reduce the skill of ocean color models.
Human adipose tissue secretes a number of proinflammatory mediators that may contribute to the pathophysiology of obesity-related disorders. Understanding the regulatory pathways that control their ...production is paramount to developing effective therapeutics to treat these diseases. Using primary human adipose-derived stem cells as a source of preadipocytes and in vitro differentiated adipocytes, we found IL-8 and monocyte chemoattractant protein-1 (MCP-1) are constitutively secreted by both cell types and induced in response to serum deprivation. MicroRNA profiling revealed the rapid induction of microRNA 132 (miR-132) in these cells when switched to serum-free medium. Furthermore, miR-132 overexpression was sufficient to induce nuclear factor-κB translocation, acetylation of p65, and production of IL-8 and MCP-1. Inhibitors of miR-132 decreased acetylated p65 and partially inhibited the production of IL-8 and MCP-1 induced by serum deprivation. MiR-132 was shown to inhibit silent information regulator 1 (SirT1) expression through a miR-132 binding site in the 3′-untranslated region of SirT1. Thus, in response to nutritional availability, induction of miR-132 decreases SirT1-mediated deacetylation of p65 leading to activation of nuclear factor-κB and transcription of IL-8 and MCP-1 in primary human preadipocytes and in vitro differentiated adipocytes.
miR-132 regulates chemokine production in human adipocytes through repression of SirT1 mediated deacetylation of NFκB.
•Unfolded protein response markers are not altered in cigarette exposed placenta.•Preeclamptic (PE) placentas had higher pPERK in decidua & villi, and IRE1 in villi.•Apoptotic inhibitor ...IκBα(Ser32/36) was lower in cigarette exposed & PE placentas.
Maternal cigarette smoking (CS) and pre-eclampsia (PE) alter placental function and expression of important proteins which maintain homeostasis. Two interlinked pathways of interest are the unfolded protein response (UPR) and apoptosis. The UPR is upregulated in the PE placenta, but no data is available on the effects of CS and how it correlates with apoptotic expression. Samples of human placental tissue from normotensive non-smokers (n = 8), women with PE (n = 8), and CS (n = 8) were analysed using immunohistochemistry for 3 UPR markers (phosphorylated PKR-like endoplasmic reticulum (ER) kinase (pPERK), inositol-requiring enzyme 1 (IRE1), activating transcription factor 6 (ATF6)), and an antibody microarray for 19 apoptotic and stress regulating markers. For the PE group compared to the normotensive group, staining for pPERK was increased in decidual tissue and villi, and for IRE1, the overall percentage of stained villi per field of view was increased. There were no differences in UPR expression comparing CS to controls. Of the apoptotic markers, only IκBα (Ser32/36), which is part of an inhibitory pathway, showed a significant decrease in the PE and CS groups compared to controls. These findings suggest UPR regulation is more evident in PE with a general increase in ER stress due to decreased inhibition of apoptosis as compared to CS for which UPR was not altered.
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